Knightshade

Yup, about as "useful" a reply as expected. I keep posting pages of detailed explaination including repeated reliable sources who all agree with exactly what I'm saying... you keep posting "Nuh uh!" I'll leave it to the reader to figure out which has no idea how brakes actually work And no, the cars motor doesn't matter either in stopping distance, assuming it continues running at all to operate the power assisted parts of the braking system ... why in the world would it, and why do you keep asking questions that make even less sense than your last ones?

So yeah, basically no matter how many people, companies, and drivers who know WAY more about this than you tell you you're wrong, you won't admit it. Glad we're clear on that. At this point there's Brembo (who make the Lexus IS-F brakes) Stoptech (who make the Lexus F-sport brakes) The guy who designs ABS braking systems The guy who ACTUALLY COMPARED BOTH PADS ON A 2IS (there's your data) All the tech saavy folks on CL All saying you're wrong and I'm right. And in many cases going into great detail about why. On your side is: You and two guys from here, who insist you're right because... well...you say so. Compelling that is. I understand you want to save face, but in light of how ridiculous you look at this point you might wanna call it a day. And why exactly are motorcycles not relevant? Do motorcycles operate under different physical laws in your world? Shockingly the answer they arrive at is EXACTLY the same as the car guys did. The pads don't change stopping distance. Your answer there ought be good for a nice laugh. And for the record most ABS systems are sampling the sensors every 7-10 milliseconds... detecting an event requiring ABS intervention shouldn't take more than a few samples. If that's not quick enough to be instant for you I'm not sure what would be... but changing the pads wouldn't change the number of sampling cycles it'd take anyway... as usual you were grasping at straws by jumping up and down and saying "it says nearly instant, that's not instant!!" while having no idea what the difference was or why there was a difference, or how much of one there was. BTW- here's a quick Bio of the Pulp Friction author, one of the extensive list of people who says you're wrong- James Walker, Jr. is currently the supervisor of vehicle performance development for brake control systems at Delphi Energy & Chassis. His prior professional experience includes brake control system development, design, release, and application engineering at Kelsey-Hayes, Saturn Corporation, General Motors, Bosch, and the Ford Motor Company. Mr. Walker created scR motorsports consulting in 1997, and subsequently competed in seven years of SCCA Club Racing in the Showroom Stock and Improved Touring categories. Through scR motorsports, he has served actively as an industry advisor to Kettering University in the fields of brake system design and brake control systems. In addition, Mr. Walker contributes regularly to several automotive publications focusing on brake system analysis, design, and modification for racing and other high-performance applications. He is a recipient of the SAE Forest R. McFarland Award for distinction in professional development/education. Mr. Walker has a B.S. in mechanical engineering from GMI Engineering & Management Institute. But I'm sure you must know more about brakes than he does... right?

And hey, if all THOSE folks aren't enough... How's Brembo? http://www.brembo.com/ENG/HighPerformance-Brakes/FAQs/ Click on the one about stopping distances- Where can I find test data on stopping distances? At the speeds that stopping distance is generally measured from (60 to 70mph), the test is primarily testing the tire's grip on the pavement. As delivered from the manufacturer, nearly all vehicles are able to engage the ABS or lock the wheels at these speeds. Therefore, an increase in braking power will do nothing to stop the vehicle in a shorter distance. Gee look, they ALSO say -exactly- what I've been telling you. They go on to explain that brake system upgrades will only be useful to reduce fade and help when making repeated/VERY high speed stops. EXACTLY like I did.

Stop replying to 6 pages of scientific explanation with "Uh...you're wrong because... you are!" Slam the brake pedal you supply maximum force input This (virtually instantly) engages the calipers with maximum force This (virtually instantly) uses the pads to transmit that force to the rotors- this will be sufficient force to lock the wheels and engage ABS. No matter what pads you use, so long as those pads are capable of engaging ABS, it will happen exactly as quickly, with exactly the same stopping distance. The only thing pads with a higher coeficient of friction would accomplish in this scenario is being capable of transmitting more force than the wheels are capable of doing anything with. Useless extra force. Since you are already at the maximum amount of braking force the system will use when ABS is engaged. Going from 0 force to enough force to engage ABS will happen in the same amount of time no matter what pads you use as long as both pads can do it. The only difference "better" pads will make is that by your 6th 100-0 stop you will be less likely to see LONGER braking distance than with a "bad" pad because you'll take longer to fade. The first stop between the two will be identical. That is what the motorcycle article told you. That is what the guy who tested the 2IS pads told you. That is what the ABS system designer for Bosch told you. That is what the folks who built the F-sport brakes told you. I'm not sure how I can make that any simpler. It's pretty clear you just refuse to admit you're wrong no matter how much evidence is presented.

Found another nice page on this BTW- it's about bikes, but it's the same physics involved- http://www.msgroup.org/tip.aspx?num=125 "Since you know that you can lock a wheel while the bike is still moving, you know that the braking energy you apply to your brakes is NOT WHAT LIMITS HOW FAST YOU CAN STOP! That limit is determined by the amount of traction your tires have." "Further, since it takes more braking energy to stop (lock) a spinning wheel than to merely slow it down, and because a sliding tire (the result of locking your brake) has less traction than one that is not sliding, your normally functioning brakes are NOT WHAT LIMITS YOUR STOPPING DISTANCE! That limit is also determined by the traction of your tires." "Now, mind you that I have been talking about a panic stop capability - or even normal braking THE FIRST COUPLE OF TIMES. " Here again, with severe repeated duty pads can make a difference in that it'll be longer before the best stopping distance ability fades away. But they CAN NOT improve the stopping distance on a non-overheated system. If the pads being used can engage the ABS system when pushing hard on the brake pedal they will stop in the same distance as any other pads that can do the same on a cold properly working OEM system. They have to, because in both cases the maximum possible force is being applied to the wheels, exactly as quickly in both cases.

What part of -the entire rest of the article says you're wrong- do YOU not understand? Unless you can point out where it mentions that pads change braking distance. Which you still have yet to provide a single reliable source for. Changing pads can- Reduce the amount of force needed at the pedal to reach a specific braking force (up to the limits of the system)- this changes the "feel" of the car, but for a single stop doesn't change braking distance unless you're not pushing the pedal all the way down. Allow for the use of smaller/fewer caliper pistons.... which is nice when designing a whole braking system but not relevant for this example. Allow for a longer time of repeating heating of the brake system without fade- Great for racing, not of much relevance for street use. Change the speed at which the pads and rotors wear- again nice, but nothing to do with braking distance. That's about all they can do though. Notice how none of those things is reduce stopping distance? But really, you won't believe me, you won't believe the guys who actually tested it ON THIS CAR, you won't believe the guy who builds brake systems for a major manufacturer for a living, you won't believe the company that makes the F-sport brakes for Lexus.... so I'm pretty sure god himself could tell you you're wrong and you'll still grasp at straws like "Oooh, they said almost in one place!"

and So your saying that your normal road conditions and "non-racing driving style" require you to use maximum braking forces? I think we need to keep the same circumstances or keep the same controlled scene to referrence. Are we slamming on the brakes or not? Are we talking about doing it just once or repeatedly? Are we talking about all cars or one make? But my driving expereince says that both driving style and braking techniques, and reaction time effect stopping distance. OOohhh!!! I get it, you think the ABS system IS the shortest stopping distance! It's not. A trained driving proffesional will and can outbrake most ABS systems. ABS is designed to help the driver maintain control of the vehicle during emergency braking situations, not make the car stop more quickly. ABS may shorten stopping distances on wet or slippery roads and many systems will shorten stopping distances on dry roads. On very soft surfaces, such as loose gravel or unpacked snow, an ABS system may actually lengthen stopping distances. So what I would like to know is how your getting maximum brake force applied WITH ABS! Your not! You getting maximum controlled braking distances. Very different. This is a ridiculuos argument or debate. The scientist in that article is only putting fourth data from an ABS results standpoint. You seem to think that the acceleration example doesn't apply here, but it does. the scientist in your article is a moron! ALL MEASURABLE PERFORMANCE LEVELS ARE LIMITED TO THE TRACTION ABILITIES OF YOUR TIRES!!!! Acceleration, cornering, braking, suspension, all of it. Why are you just selecting the brake system to apply that statement to? Heres a question for you to chew on: A truck that weighs 3500 lbs with the body of the truck raised to 35 inches, an SUV that weighs 3500 lbs, and is 24 inches off the ground, and a BMW M6 that is 3500 lbs. that is 14 inches off the ground, and a LAmbo that is 3500 lbs that is 6 inches off the gorund. All have the exact same tires and all have the exact same brake system, and brake pads. Your saying they would all stop exactly the same distance from 80 mph? And yes, all have the same ABS system. Hmm, why do I not think so? There is alot more to the math of physics than you have touched upon. So, let's again talk about the pads only here for a moment. There are only two friction points for braking. The pads on the rotors and the tires on the road. And your saying, or atleast the report your citing states that the pads on the rotors don't matter, all that matters is the friction point between the tires and the road? And if I use a full race pad, like a Porterfeild R-4's or Performance Friction Brakes Compound 01, and 03 which offer great cold bite, coming in at 250 degrees and maintains a higher torque rate thru 1200 degrees with a smooth release in order to not overslow the car or overwhelm the cars set up. We are talking about just pads here. Which can easily be obtained. I think you have just misinterpreted the article. Oh, and btw, he said of course stopping distances were measured with several different compounds to see what produced the shortest stopping distances and they tested wear life. I can't figure out why you keep bringing up: Non-ABS systems Racing Since neither is what the topic is. Braking distance, as generally measured for use in repeatable testing, is not "Which brake engineer can best stop the car after you've raced it for 3 hours" It's a cold stop going from 0-60-0 (or 100, or whatever specific speed is used). And on ABS car it's essentially slamming on the brakes to engage the ABS system. Because anything else can't be easily repeated by anyone else. And that's the kind of stop that will matter to the average street driven car.... the single panic stop on an otherwise non overtaxed braking system. As I've said repeatedly, pads CAN NOT change this stopping distance. So did the author of the article, who designs ABS systems for a living. So did the guy who -actually tested this on a 2IS and found identical braking distances with both the high-friction high-dust pads and the low-dust TSIB pads. So did stoptech who make the F-sport brakes. What pads -can- do is reduce fade after extreme thermal conditions occur (ie repeating braking hard on a race track for example). The pads themselves still aren't reducing braking distance in and of themselves even then, they're just allowing the best stopping disance to continue to happen a bit longer than more thermally sensitive pads would... They're keeping the braking performance consistent longer. They still can not "improve" the distance it takes for a single cold system stop. They just make it take more repeated abuse of the system before that distance gets significantly longer.

Thanks! Here's a quote from that article that might sound familiar! "The brakes don't stop the vehicle - the tires do. The brakes slow the rotation of the wheels and tires. This means that braking distance measured on a single stop from a highway legal speed or higher is almost totally dependent upon the stopping ability of the tires in use" Gee, where'd we hear that before? It goes on in some depth, mostly echoing the contents of the pulp friction article, but it has some other good stuff in it. When it gets to discussing pads it mentions a few areas they matter- service life, thermally (for racing for example)... NOT stopping distance. But I guess me, some folks on club lexus who actually tested this stuff, a well known brake engineer, and stoptech (who make the F-sport brakes BTW) all don't know what we're talking about. Citing a company that is trying to sell you brakes? This means that braking distance measured on a single stop from a highway legal speed or higher is almost totally dependent upon the stopping ability of the tires in use Yes. The fact even the people who want to sell you pads are saying pads don't stop the car faster should mean something. I admit many brake companies aren't quite as honest as that. The almost there is to account for environment (as you like to note, a 50 mph head or tail wind would change distance, as it's an outside force entering the equation). A poorly maintained brake system (like water in the fluid, worn out pads and rotors, etc) could impact it. At no point in the entire multi-page article do that claim that pads alone can improve stopping distance on an otherwise functional modern brake system... In fact when they discuss pads at all they're very clear that that is NOT one of the things pads can change. Just like the professional brake engineer told you. Just like the guy on CL who tested the two pads told you. Just like I told you.

Thanks! Here's a quote from that article that might sound familiar! "The brakes don't stop the vehicle - the tires do. The brakes slow the rotation of the wheels and tires. This means that braking distance measured on a single stop from a highway legal speed or higher is almost totally dependent upon the stopping ability of the tires in use" Gee, where'd we hear that before? It goes on in some depth, mostly echoing the contents of the pulp friction article, but it has some other good stuff in it. When it gets to discussing pads it mentions a few areas they matter- service life, thermally (for racing for example)... NOT stopping distance. But I guess me, some folks on club lexus who actually tested this stuff, a well known brake engineer, and stoptech (who make the F-sport brakes BTW) all don't know what we're talking about.

Except we're not discussing the track, and we're not discussing "driving styles" We're discussing stopping distance. Which is measured with maximum braking force applied. If it was measured based on how hard you felt like pushing at any given moment then it'd be useless to compare one test to the next. The ford article you quote is using a car WITHOUT ABS. Which means the results are relying on the driver to modulate lockup of the wheels. They even mention this in the article: "The hardest part of stopping a car without ABS in a short distance is avoiding wheel lockup and skidding." They saw variance of almost 40 feet with the SAME pads because of this in their testing. With the new pads again they saw variance as much as 30 feet with the SAME pads. Hardly reliable data in that case. They do note the better "feel" and less fade of the other pads... both of which I mentioned as things that pads -can- improve for you. Your acceleration example has no bearing on stopping though, but I admit it's a great red herring. It'd be like saying it's impossible that a fat guy and a skinny guy will fall at the same speed, because clearly one can jump higher than the other going the other direction. It makes no real world sense, but it sounds like it should. (hint- the heavy and light guy will fall at exactly the same speed all else being equal) What I'm sure your dads group found was that different pads were good for different things, such as less fade, better pedal feel, longer lasting, etc. If they did real scientific testing on an ABS car and found different pads alone change stopping distance, by all means please provide their data and testing. But let me try to clarify the situation we're actually discussing- On a properly designed OEM braking system with ABS, which our cars have. We are discussing stopping distance under a normal road condition. This essentially means you need to stop in the least distance possible and will be essentially slamming the brake pedal, thus applying maximum force for brake input. In this case the calipers then contract with maximum force. The pads transfer this force to act as friction against the rotors. All of this happens almost instantly. Any pads that can transfer sufficient force from the calipers to the rotors so as to engage the ABS system, which again will happen almost instantly, will stop the car in the same distance all else being equal. This is exactly the point the pulp friction article makes. This is also exactly the results actually seen by the user who tested the high dust and low dust pads against each other and found identical braking distances with both. You can keep tossing out irrelevancies like "Uh, what if you're racing!" or "Uh, what if you change the brake proporitioning?" but those aren't what we are discussing. We're discussing the standard stopping distance between two sets of pads, both of which are capable of transfering the force required to engage ABS. And both pads will stop IN THE EXACT SAME DISTANCE. They have to. Because both are transferring the maximum possible useful braking force to the rotors The PF article even gives you all the math you need to prove it. Changing your pads can change a lot of things. I listed some of them. Stopping distance ain't one of em. (again, on a modern OEM system with ABS... I'm sure you can find some bizarrely configured old brake system where almost anything can change it including the type of shoes you wear).

Every component of tbe braking system has an effect on: 1) Driver tuning- that is, the "feel" of the system...does it require a little or a lot of pedal effort to get maximum effect, are the brakes smooth or grabby getting there, etc.. 2) Thermal control- If your brakes already work consistently under the conditions you drive it then doing things like putting on larger rotors will enhance nothing but the weight of the vehicle... However if your conditions are extreme enough (racing for example) then super sizing some parts can help manage this. 3) Temperature sensitivity- How quickly you'll need thermal control basically... this is usually a less desirable way to address heat issues than number 2, but it's cheaper. HERE is where pad material, fluid used, etc can matter... but it has no bearing on the standard stopping distance of a street car. 4) Compliance- Basically the overall efficiency of wear, feel, etc on the system. That's it. Not stopping distance. Note the above assumes a properly designed braking system, which OEM systems generally are these days. Obviously you can find a crazy example where a 1-ton truck has a system with 9" discs put on it and larger discs will stop it better. That's simply not the case with a properly built OEM brake system though... where changing a brake system component can certainly change a number of things, pedal feel, relative input required for maximum force, consistency under abuse at the track, unsprung weight, etc... but NOT typical stopping distance. As Pulp Friction concludes- If your ultimate goal is to decrease your stopping distance, look no further than the four palm-sized patches of rubber connecting your ride to the ground. Since that is what actually stops the car. I'd again encourage anyone whose mind isn't entirely closed to science and evidence to read that article... it explains in considerable detail what each braking system component does and does NOT do, and what you can, and can NOT, hope to change by changing that component. It might well save you a fair bit of money by understanding that just throwing a big brake kit on a car, or wasting money on drilled rotors, isn't always a great idea... for most folks who do it it's probably a bad one.

No data then huh? That's almost as good as saying your butt dyno says your new intake adds 20 HP. No, it's an understanding of physics. It would be impossible for it change the braking distance because the pads are not what stop the vehicle. It'd be like you asking me to provide data to "prove" that stickers don't add horsepower. Stopping power isn't just about clamping down on the disks with just anything that will grab them. If that were the case then the optimum would be carbon-carbon pads and rotors. Better yet stick a broom handle in the spokes and stop even faster. And no, I didn't ask you to prove a negative. Perhaps this or some of the other articles from a Google search will help you gain a better understanding of the factors related to brake pads and stopping ability. http://www.tirerack.com/brakestechpage-1/88.shtml http://www.sdt.com.au/safedrive-directory-...INGDISTANCE.htm http://www.bendix.com.au/ABSESCReplacementBrakePads.aspx http://ford.justanswer.com/questions/19ypo...erceptor-failed None of those links say that changing pads change stopping distance. The ford link is about ABS, which isn't the topic... the only mention of brake pads is they need to be capable of engaging ABS- WHICH WAS EXACTLY WHAT I TOLD YOU. If they can engage ABS they'll exert the maximum possible braking force. The Bendix link doesn't mention braking distance -at all- It does mention performance, which could be relevant to repeated frequent braking like at the track.... the one place I mentioned pads CAN matter because you want a consistent coeeficient of friction across multiple frequent stops.... so once again it AGREES WITH ME AND SAYS NOTHING ABOUT YOUR POINT. The SDT link is incredibly vague... it lists brake pads along with 10 other things (including the wind you're a big fan of).... but doesn't say why any of them matter. Once again, pads so worn they can not engage the ABS system or otherwise apply maximum braking force certainly CAN impact braking performance. But that isn't the topic. We're comparing two brake pads that both can do that. And the tirerack link mentions noise, dust, and smoothness...and pads certainly can change those. It says nothing about braking distance. Seriously, if you were correct, you'd think you could find one reliable source that actually says what you are saying. Ideally one that explains the science behind it. You know, kinda like my article does for 5 pages in great depth saying you're wrong. The only folks I've seen say it are people selling brake pads...or people who wasted money on em and want to justify their purchase.

I'm pretty sure changing the rotors, and calipers, and pads all at the same time isn't a real useful case for proving the pads by themselves change anything. Barkat- what article of yours did I not read? I've still yet to see you post one. - Wait, my bad, you went back and edited your old posts with links after the fact- I'll go look at those now The Pulp Friction article pretty clearly explains where you -can- see improvements from different pads... But stopping distance is NOT one of those areas, and it's quite clear about that. When I posted reference to someone having actually TESTED the two pads, they not only found results that -exactly- matched what I'm saying, they explained it using the exact same reasoning I'm using. So on my side we have: The actual facts. A world renowned brake systems engineer who says exactly what I'm saying. A number of pretty technically respected other forum users on CL who all agree with me (Lance Wolrab and Genby among them) On your side we have: You and one other forum user who insist it can't be true. But I understand... it's like arguing with the guys who insist "drilling" rotors is a good idea for a street car... no matter how much science you explain to them, they'll insist they're right. But go re-read page 5 of the article... where he explains that there are 4 areas you CAN impact by making brake system changes like different pads, larger rotors, etc... None of those areas is stopping distance though.

Since you seem to want a test of what we already know is true though, here's a guy who did it- http://www.clublexus.com/forums/showthread.php?t=290476 Read post number 7.... even better, lemme quote part of his explanation for why he got identical braking distance with both sets of pads- "Another thing to remember is that the brakes can only effectively stop the car as long as the tires don't loose traction (lock up) and the ABS is going to do this for you, so realistically the only thing in question here is the ability of the brake pad to clamp the rotor tight enough to make the wheel lock and it does that just as effectively as the original pad does" Gee, that sounds familiar. He goes on to add that for road racing/tracking you might see fade sooner with the new pads, but not in street use. Huh, that sounds kinda familiar too...

The pads do stop the car, as they stop the wheel/tire assembly. The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels. The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs. Read up. What stops the car is the force between the road and the tires. Period. I suggest -you- read up...lemme help http://www.scirocco.org/faq/brakes/pulpfriction/pfpage1.html The author has forgotten more about brakes than any 10 guys on here know. He's a world known brake engineer. Page 3 is where he gets to brake pads... Here's the most relevant parts- "Ths part might surprise some and offend others, but it is a big misconception that changing brake pad material will magically decrease your stopping distances. In fact, you may have even seen published "data" which attempts to correlate stopping distance to friction coefficient. Although it may appear that there is a relationship between the two, there really isn't, and here's why." He then goes on the explain why.... later he adds- "Brake pads with radical changes in coefficient over their operating range are not a racer's best friend. Be sure to select one that remains relatively stable under the operating conditions you are expecting, but don't expect any shorter stopping distances, because the brake pads don't stop the car" And especially- "So why change brake pad materials in the first place? Because increasing the coefficient of friction can allow for the use of smaller/fewer caliper pistons and/or will reduce the amount of pedal force that the driver needs to apply in order to generate a given rotor output force." We're not changing the pistons here though, so that's not relevant. And the amount of input force isn't either, as either pad can engage the ABS system, which means the driver is already applying the maximum possible pedal force. So, once again, I tell you, it's physically impossible for the two similar pads that both can engage the ABS system to change braking distance by a measurable amount. And so does the author of the article. Please don't ever mention physics here again. I think it's time for your remedial course. When you pass that then I'll listen. So you have nothing to actually dispute the professional brake engineer I quoted. Gotcha. As an aside, I encourage everyone to read that article, it dispells a lot of common misconceptions about brakes... especially good for the folks who think "drilling" is a good idea for rotors too. You guy says wind is a factor. Will a 50MPH wind stop your car faster than a 10MPH wind? Same thing goes for pads. The quicker they get your tires to stop, the quicker your car stops. Argue with that point all you want mr expert. But the pads do NOT make the tires stop faster. It's not possible for them to do so. The -only- thing the pads do is transfer the clamping force of the caliper to the rotor. Once you are at maximum force, where ABS engages, the ONLY relevant thing to the car stopping is the coefficient of friction between the tires and the road. That's it. Put any brake pad you want on the car and that'll still be true. So any pad that engages ABS will produce the same stopping distance as any other, all else being equal. Seriously, a guy who has spent most of his life designing and consulting on brakes with companies all over the world wrote that article. He just told you you're wrong, pads don't change braking distance. Yet you're still arguing about it. Without any sources, evidence, or anything really except insisting none of the facts are true. Why? And please, show me some of your 100 sources. Ideally from someone who is NOT trying to sell you their brake pads.

The pads do stop the car, as they stop the wheel/tire assembly. The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels. The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs. Read up. What stops the car is the force between the road and the tires. Period. I suggest -you- read up...lemme help http://www.scirocco.org/faq/brakes/pulpfriction/pfpage1.html The author has forgotten more about brakes than any 10 guys on here know. He's a world known brake engineer. Page 3 is where he gets to brake pads... Here's the most relevant parts- "Ths part might surprise some and offend others, but it is a big misconception that changing brake pad material will magically decrease your stopping distances. In fact, you may have even seen published "data" which attempts to correlate stopping distance to friction coefficient. Although it may appear that there is a relationship between the two, there really isn't, and here's why." He then goes on the explain why.... later he adds- "Brake pads with radical changes in coefficient over their operating range are not a racer's best friend. Be sure to select one that remains relatively stable under the operating conditions you are expecting, but don't expect any shorter stopping distances, because the brake pads don't stop the car" And especially- "So why change brake pad materials in the first place? Because increasing the coefficient of friction can allow for the use of smaller/fewer caliper pistons and/or will reduce the amount of pedal force that the driver needs to apply in order to generate a given rotor output force." We're not changing the pistons here though, so that's not relevant. And the amount of input force isn't either, as either pad can engage the ABS system, which means the driver is already applying the maximum possible pedal force. So, once again, I tell you, it's physically impossible for the two similar pads that both can engage the ABS system to change braking distance by a measurable amount. And so does the author of the article. Please don't ever mention physics here again. I think it's time for your remedial course. When you pass that then I'll listen. So you have nothing to actually dispute the professional brake engineer I quoted. Gotcha. As an aside, I encourage everyone to read that article, it dispells a lot of common misconceptions about brakes... especially good for the folks who think "drilling" is a good idea for rotors too.

The pads do stop the car, as they stop the wheel/tire assembly. The faster they are able to do that the shorter the stopping distance. It can vary 10 to 20%. The effiency with which the pad is able to slow down the wheels and hence the car is not the same for different materials. The pads don't just grab the rotors and stop the wheels. The coefficient of friction of the pads is a major factor in stopping distance. I'm talking one panic stop from road speed. There is still energy (heat) to be dissipated here as well as initial friction to slow the wheels way before the lockup occurs. Read up. What stops the car is the force between the road and the tires. Period. I suggest -you- read up...lemme help http://www.scirocco.org/faq/brakes/pulpfriction/pfpage1.html The author has forgotten more about brakes than any 10 guys on here know. He's a world known brake engineer. Page 3 is where he gets to brake pads... Here's the most relevant parts- "Ths part might surprise some and offend others, but it is a big misconception that changing brake pad material will magically decrease your stopping distances. In fact, you may have even seen published "data" which attempts to correlate stopping distance to friction coefficient. Although it may appear that there is a relationship between the two, there really isn't, and here's why." He then goes on the explain why.... later he adds- "Brake pads with radical changes in coefficient over their operating range are not a racer's best friend. Be sure to select one that remains relatively stable under the operating conditions you are expecting, but don't expect any shorter stopping distances, because the brake pads don't stop the car" And especially- "So why change brake pad materials in the first place? Because increasing the coefficient of friction can allow for the use of smaller/fewer caliper pistons and/or will reduce the amount of pedal force that the driver needs to apply in order to generate a given rotor output force." We're not changing the pistons here though, so that's not relevant. And the amount of input force isn't either, as either pad can engage the ABS system, which means the driver is already applying the maximum possible pedal force. So, once again, I tell you, it's physically impossible for the two similar pads that both can engage the ABS system to change braking distance by a measurable amount. And so does the author of the article.

But the brake pad isn't what stops the car. So I guess it's more akin to you asking which brand of sticker adds more horsepower. I will note that for -track- use the pad material can have greater relevance as after hot lapping a few times the coeficient of friction can change significantly.... but for street use? pads is pads. If it can kick ABS on it'll stop exactly as well as the next pad since you're at the limits of the brake system there. And even ON the track the pads only matter for more consistent braking without fade under extreme conditions. Just changing pads can't stop you in a shorter distance, because the pads don't stop the car.

No data then huh? That's almost as good as saying your butt dyno says your new intake adds 20 HP. No, it's an understanding of physics. It would be impossible for it change the braking distance because the pads are not what stop the vehicle. It'd be like you asking me to provide data to "prove" that stickers don't add horsepower.

The brakes don't stop the car. So long as the pads provide sufficient friction to engage the ABS system different pads can't change braking distance for a given stop.

Not sure about the northeast, but I know in CA you can easily get a 250 at or under invoice...nobody pays anywhere close to MSRP. If you can find one like you want sitting on the lot I don't see why you shouldn't be able to get a similar deal near you, especially this close to the 09s coming out and with the economy in the toilet.

Normal and synthetic are completely compatible, so just drain the old stuff and put in the synthetic, no need for a flush.... As to change intervals, depends what you use.... something like Mobil 1 can comfortably go at least 10k miles, something like Amsoil can comfortably go 25k miles (though I'd still change the filter every 6 months) For the oil light- 1. Turn the engine switch OFF. 2. While pressing the trip meter reset knob, set the engine switch to the IG-ON mode. Continue to press and hold the knob until the trip meter displays 000000. (make sure it's on the odometer display, not trip a or B )

Yeah, the install itself would be custom, and you'd have to keep the factory head unit brain wired into the car somewhere (usually glove box or trunk) in order to keep the AC and such functional.... folks have certainly done it, but it's not as simple as pull out the OEM unit and pop in a new one.

At this point in the year, with this economy, if you're looking for an 08 in CA I'd expect you'd be able to get one at invoice or damn close to it

The dealership will have all the records on all service done at any Lexus dealership. If it has had regular 5k oil changes at the dealer and you're already at 35k I'd probably go ahead and get the 40 and 45k ones there too just for "Look I'm protecting my warranty" peace of mind... after that switch to synthetic and longer change intervals. Every 5k is just an oil change- make sure you TELL them just do an oil change, or they'll charge you 3 times as much and still just do an oil change plus an "inspection" you don't need to pay for since they're gonna point out anything to you they notice anyway. At 30k they (should have) changed the air filter and AC cabin filter (which are easy to do yourself and vastly cheaper) and the brake fluid. 35 and 40 thousand are just oil changes.... 45k is oil change plus clean the AC filter (again save $ and do it yourself) 50 and 55k are just oil again...and 60k is the same as 30k plus changing the spark plugs. Here's the whole maint. schedule/warranty manual/etc- http://www.lexus.com/pdf/service/Sedans.pdf and be sure to check the list of TSIBs for the car and get any you want/need done while the warranty period is in force, they stop being free after that.