AZ Mike

Based on people I have talked to and reviews that I have read, it is a one way street. 1) Use of regular unleaded in a vehicle that recommends premium may result in loss of power and fuel economy 2) Use of premium unleaded in a vehicle that recommends regular typically yields no beneficial results, and some argue negative results. I.e., you may have negative results stepping down from recommended, but do not get positive results when stepping up from recommended.

Thanks for the input, moose. One additional question: what year is your LS400, and how many miles, and what was the condition of the old belt upon removal and inspection?

OK....I get a kick out of the term "radiator fluid". Most of us just call it coolant. ;) In addition to what you have mentioned (and I am pretty sure that the idea came from a thread on this board), replacing the PCV valve grommet is a good idea. The old one starts getting pretty brittle and doesn't provide as good of a seal with the valve. Be careful when removing the old one so that you don't lose any pieces into the valve cover. Brake fluid is called for every 30K miles in my owner's manual supplement. Replace a/c (cabin) air filter.

I haven't changed anything on my Lexus from stock (i.e., I don't know what changes will produce what yield), but if horsepower is your goal, you are much more likely to see improvement from increased air intake and exhaust outflow than from spark plugs. If you are really serious about horsepower gains, you can supercharge. No disrespect, but looking for horsepower gains from spark plugs is a huge joke in my opinion.

Moosebeer--about how much time do you have into the project? Thanks

For what it is worth, I have never seen an independent study of the same cars driven exactly the same way in the same conditions over a long term to suggest that hyper-advertised wonder plugs have any benefit whatsoever other than to the bottom line of said spark plug manufacturer.

In my research, the vast majority of so called experts suggest that there is absolutely no value to using a higher octane than is recommended for your engine. Remember that octane is the ability for gas to withstand predetonation; it is not a measure of power. Yes, newer cars that recommend premium can generally get away with regular due to the ECU's ability to !Removed! timing in order to avoid pinging. However, this will often be accompanied with a decline in optimum and result in slight decreases in horsepower and fuel economy. This has to do with the ECU adjusting things to accomodate the lower octane, and not the fuel itself. So no, using higher octane than is recommended does NOT improve mileage and power.

Another vote for Costco batteries. I have used them in several cars with great success.

"Lower octane "pump" gas should give better mpg and make more power". Perhaps I am merely a knucklehead, but everything I know about octane is that it is a measurement of resistance to "pinging" and has nothing to do with power. The LS400 does not REQUIRE, but RECOMMENDS premium fuel. I do not know all of the specifics behind the engineering of the engine, but this typically happens when the engine runs at a higher than typical compression, which would therefore increase the propensity for predetonation (i.e., pinging) with regular fuel. The engine runs at its optimum efficiency using the higher octane. You can run on regular fuel, but as mentioned, the ECU will !Removed! the timing to prevent predetonation, and in the process, runs at a less than optimum efficiency. Therefore, based on my limited knowledge, most modern cars that RECOMMEND premium fuel can run fine on regular fuel, but will likely have a small reduction in fuel efficiency due to the engine not running at its optimum (which of course proponents of regular fuel will say is offset by the cheaper price of regular fuel). I don't know that there would be any long term ill effects on the engine from using regular fuel.

I wasn't sure that I wanted to tackle the timing belt. Looking at the DIY, it doesn't look all that difficult; just time consuming. Am I wrong here? Is there anything about it that is particularly tricky? I only have about 62,000 miles, but it is a '99 running on the original timing belt, which means it is over 9 years old. It doesn't sound like many people experience wear based on time (instead of mileage), but I don't know how far I want to push it.

I'm not saying that a 4X4 SUV is silly. I'm saying that a properly equipped 98+ Lexus LS RWD sedan with all its technology gizmos (VSC, ABS, snow mode transmission setting, heavy duty snow tires) will get around in moderate ice and snow just as well as a 4WD SUV. There is definitely a place for a 4WD SUV when the snow is deep and roads are poorly maintained. So you would rather be in in your "old Grand Cherokee" in a crash than in your 99 LS400? Do you mind if I don't ride with you? I know the odds from over 30 years the auto insurance industry and I certainly don't want to be in an "old Grand Cherokee" during a crash. SUVs are more likely to be in a serious crash in the first place and they have a much higher frequency of rollovers. We travel and rent cars quite a bit -- I never, ever accept an SUV as a rental car. The last time Hertz tried to foist an SUV on us when they ran out of "normal" full size cars, we drove out their lot in an Infinity M35 --> http://us.lexusownersclub.com/forums/index...amp;hl=Infinity You are correct. You did not say that a 4X4 SUV is silly. You said, "I regard the modern fascination with 4WD vehicles as silly." You are free to ride with whomever you please so long as you are invited. However, my comment referred to driving when there is a risk of sliding off the road, and had nothing to do with a crash. My reasons are in the quote above. I am not trying to pick a fight and say that an LS can not do OK on snowy roads with the proper tires. However, that wasn't the question. The question was whether it would be better to purchase an old 4X4 for winter use or put snow tires on an LS. Seeing as I own a Grand Cherokee and an LS400, and have driven both in the snow, I was merely offering my opinion, which is, given a choice in snowy conditions, I'm taking the Grand Cherokee and leaving the LS400 in the nice warm garage. In my experience, I feel much more confident driving the Jeep in snowy, icy conditions. I have never been in a crash in either the Grand Cherokee (175K miles) nor the LS400 (62K miles), so i can neither confirm nor deny your allegations about which fares better in a crash. But again, this is an entirely different topic than the question at hand.

I used www.irontoad.com last Spring when I was purchasing parts for my 60K service and rear brake pads. I found them the cheapest in total for what I needed. There is also Park Place Lexus and Sewell Lexus and some others.

I just thought this was funny.....in one paragraph, says 4 wheel drive is silly. In the next paragraph, states that only two cars made it up an icy and snowy street......the Lexus with snow tires and a 4 wheel drive. So maybe 4X4 isn't so silly after all....... If I was going to be risking sliding off the road, I would MUCH rather be in my old Grand Cherokee than my Lexus. First, the Jeep handles better in snow. Second, if it does slide off the road, I will be able to drive it back onto the road (clearance, traction, etc). Third, if I slide into something, I would be much less bummed banging the Jeep than the Lexus.

I have an LS400 and a Grand Cherokee.....oh, and a Honda S2000 for fun. The Jeep has been relegated to Home Depot/Boy Scouts/hauling the dogs/camping/towing etc. duty (it is a '94 w/ 175K miles and runs great). The Jeep was my only vehicle for 3.5 years in Park City, UT. It performed great in the snow. I have not driven my Lexus in snow (that white stuff doesn't fly often in AZ), so can't speak to a comparison. However, a 4X4 almost always will outperform a rear wheel drive in the snow. Of course, a Jeep ain't no Lexus. Comparatively, it is noisier, has less fuel economy, is not nearly as plush, and is more likely to drip oil on your garage floor. I don't know what Jeep forums you have looked at, but you can learn everything you want to know about a Grand Cherokee on www.jeepsunlimited.com. One plus is it would give you a wheelin' rig. Chances are you would never take your Lexus rock crawling.

Any idea how similar/different the process is for a Generation 2 LS400 (1999)? Has anyone done that thorough of a tutorial for a Gen 2?

I replaced hood struts once using some off of ebay that were a fraction (20%) of the cost of OEM. They work perfectly fine; no complaints. I'm not sure how they could bend a hood unless they are the wrong size or installed incorrectly, AND the hood forced down despite strut interference. For most, if not all critical parts, OEM is the way to go. However, a hood strut is a very simple part, requiring only that it be the correct length and have the correct attachments. In my opinion, the argument over an OEM vs aftermarket hood strut is similar to the argument over an OEM vs aftermarket mud flap......you buy the right size, and it will work. Your new struts will have instructions in them. The process is simple. There is an attachment at the top and bottom. It is critical to have a helper for this one, as it is difficult to balance the weight of the hood while installing the new struts. as mentioned the complete install of both sides is <10 minutes.

Which transmission fluid does your owner's manual call for? Type II or Type IV? I am only familiar with Type IV. If your owner's manual calls for Type II, did Type IV replace Type II and is it backwards compatible? I do not know anything about Type II, so either you need to do a little more research, or someone else needs to chime in. More information than "I have black transmission fluid" would be helpful: Is this car new to you? I.e., do you know how many miles are on the vehicle since the last transmission fluid change? How does the transmission function? The fact that the fluid is dirty is significant, but of more importance, how is the transmission operating? I.e., does it shift smoothely at appropriate rpms, etc.? If the transmission operates properly, I don't see anything wrong with doing multiple short interval drain and fills to refresh the fluid. I have never dropped the pan on my transmission (drain and fills only), and don't know about the filter; I can't find mention of the transmission filter in my owner's manual maintenance supplement. I DO know that with some vehicles (don't know about Lexus), that a machine operated reverse flush of really dirty transmission fluid can do more damage than good to the transmission. I don't even know if Lexus does reverse flushes, but it is worth asking.

With respect to engine oil, differential oil, and brake fluid, you rarely hear about a particular brand of oil causing problems as long as normal fluid changes are made. For example, when is the last time you heard about someone's engine failing because they used Pennzoil instead of Castrol? Or 10w-30 instead of 5w-30? This tends to be a different story with automatic transmissions. First, there are substantive changes between different types of transmission fluid (Dexron, Mercon, etc.), and it is well documented that using the wrong type of transmission fluid can do significant harm, if not destroy, an automatic transmission. Perhaps Royal Purple or Amsoil can be used in place of Toyota Type IV with no negative effect; I have no idea. On the other hand, given the higher risk that the wrong fluid can do substantial damage to an automatic transmission, and given that there is no evidence that Royal Purple or Amsoil are any better, why risk it? The only Toyota fluid I use is the Type IV transmission fluid, and I see no reason to change that.

First of all, it would be helpful if you state which fluid you are draining and refilling. I will assume transmission fluid, since you mention the color "red". Items you mentioned that you did not specify: 1) Did you torque the drain bolt to spec? 2) Did you replace the crush washer with a new one? Always clean up the drain bolt area when you are done draining and have reinserted the drain plug. This way, you can have a high level of confidence that the drain plug is your problem if you later find any fluid there. 24K is not a lot of miles on a transmission. However, if the fluid is opaque, it is dirty, and you may want to do a drain and fill at each oil change until the fluid is somewhat translucent (i.e., think of the difference between clean and dirty engine oil). Be certain to use Toyata Type IV transmission fluid.

I change mine every 30K miles. You can get them on the pretty inexpensively.

The ONE time I have ever purchased an auto extended warranty was with my Honda S2000. I figured there is a convertible top, high performance engine, etc., so maybe it is worth it. I thought I was smart purchasing a 3rd party policy for several hundred dollars less than the manufacturer policy. First, the warranty company, one of the largest in the US at the time, went bankrupt about 3-4 years later. Second, I have never had a single problem (covered by warranty or otherwise) in my 8 years of ownership. My conclusion: purchasing an auto extended warranty is a waste of money, and if someone wanted to buy one anyway, I would strongly recommend a manufacturer policy (less likely to go bankrupt, unless it is a US auto manufacturer!!) I own a '99 LS that has never needed anything but standard maintenance.

FWIW, I have NEVER "gotten my money back in repairs" on ANY extended warranty on ANY product I have purchased. Maybe I'm just lucky and buy problem-free products. Most of the financial gurus recommend NOT purchasing extended warranties, as few people come out ahead financially after buying them. Salesmen earn a LARGE commission on the sale of these policies; if the salesman is telling you not to buy it, that says something.

Also, use only Toyota Type IV Transmission Fluid.

It would appear that Amsoil is a good oil. Significantly better than Mobil 1 or other synthetics? Arguable. Ask any Amsoil devotees, and they will send you charts showing Amsoil to be one of the better oils in various technical tests. What do these charts mean to the actual performance of your car or mine? Well, maybe you can wipe up oil drips from your oil change with them. ;) The only sure way I know of to test the different oils in your own vehicle is to get used oil analyses and make the comparisons. However, this runs $22 per UOA from Blackstone, plus postage. The other alternative is to use a quality oil at the intervals recommended in your owner's manual; a less scientific, but less burdensome on the wallet option. Unless you are using extended oil change intervals, I am not convinced that the use of synthetic oils makes sense. The one proven benefit of synthetic oils is that they do not break down as quickly as conventional oil, therefore serving the oil's purpose for a greater number of miles. Other benefits are arguable. With respect to transmission fluid, I am in agreement with jcrome04: Toyota Type IV ATM fluid only. In my experience, transmissions are the one component that appears to be most sensitive to the fluid used. For example, there are many who change up fluids in the crankcase and differentials with no ill effect. However, there are many instances where people using different fluids (than called for in owners manual) in the tranny leads to all sorts of problems. For transmissions, my personal choice is to strictly stick to OEM fluid. This may be overkill on my part, but I would rather be safe than sorry.

My owner's manual supplement states that the oil change intervals are either 5,000 miles or 4 months (if you drive under the "special operating conditions"), or 7,500 miles or 6 months if you drive "under light, non-commercial duty for distances greater than 5 miles in temperate climates". The manual does not state this, but if I personally were to use the 7,500 mile interval, I would use synthetic oil, as its primary advantage is that it does not break down as fast as dino oil. Dino oil should be fine for 5,000 mile intervals. Some say that synthetic oil decreases engine wear over time and possibly leads to a slight increase in mileage, though evidence of this is arguable. For example, there are a lot of vehicles out there with several hundred thousand miles that have used nothing but conventional dino oil. Like in many aspects of life, there is a "placebo effect" wherein we believe there is an improvement because we are using a better/more expensive alternative. As best I can tell, there are two proven reasons to use synthetic oil: 1) for extended oil change intervals; and 2) to make you feel warm and fuzzy that you are using synthetic oil.