Does Octane Matter?

[LovinItGoodLS400]

I been driving my dad's LS 400 ever since I was 15, but when I started college, my dad started driving the car again, and I found out when I got the car back this year, that for the past 3 years he's been putting in regular gas when it asks for premium. He claims his collegues with Mercedes always put regular gas for years, with no problems. I noticed that the car makes a LOT of noises, and recently whenever I turn on the ignition, it would take forever to actually START, sometimes short-circuiting the battery when I turn off the engine, and forget to close a window, so I turn it back on immediately, and it just DIES! So I have to flag somebody down to charge the battery for 5 minutes so I can start it back up again! My first thought was that it could be the battery, but the battery was changed last year, unless its a defective battery? Also I notice white smoke coming from the exhaust pipe, most often in the mornings, even when its not cold outside! Also, I noticed couple weeks ago, the fuel gauge would not go all the way to the top, to FULL! I was just wondering, could any of these problems stem from using regular gas??? Oh is the car just falling apart, as older cars tend to do, especially since this car is 15 years old! Please help! I really love this car for the past 15 years (love at first sight), and I want it to last few more!!!

[rl9905]

I suggest that you maybe try putting in a bottle of Fuel Injector cleaner for your car. They usually cost around 3 or 4 bucks for the regular ones. There's the Chevron Techron Concentrate fuel injector cleaner which is about 10 bucks at pepboys and Z-Max for about 25 bucks.

I've tried the Chevron and it works pretty good. After a bottle of that, I notice a big difference in acceleration, engine noise, and the idle RPM was a lot better. Using a bottle of this will help clean out your system. Try it out.

What kind of battery are you using? How much Amp is this Battery? If you just replaced the battery it could be that your car is not charging it. One thing you might wanna try to do is clean the battery connectors. As time pass by, the connectors might become corroded especially after 15yrs. Use soap and water and a brush to clean it. Dry the connectors after you clean them. It can also be that you have a loose connection to the battery so be sure that the connectors are TIGHTLY screwed to the battery.

What do you mean by "...recently whenever I turn on the ignition, it would take forever to actually START." Do you mean it takes forever to crank the engine? Or takes forever to warm up and run?

How bout the gas ocatane? Ever since you got the car back from your dad using 87 Ocatane, did you switch back to 91 octane?

One last thing, Do you service your car every 5k miles at Lexus, at those Jiffy Lube places or yourself?

[Lexusfreak]

I been driving my dad's LS 400 ever since I was 15, but when I started college, my dad started driving the car again, and I found out when I got the car back this year, that for the past 3 years he's been putting in regular gas when it asks for premium.    He claims his collegues with Mercedes always put regular gas for years, with no problems.  I noticed that the car makes a LOT of noises, and recently whenever I turn on the ignition, it would take forever to actually START, sometimes short-circuiting the battery when I turn off the engine, and forget to close a window, so I turn it back on immediately, and it just DIES!  So I have to flag somebody down to charge the battery for 5 minutes so I can start it back up again!  My first thought was that it could be the battery, but the battery was changed last year, unless its a defective battery?  Also I notice white smoke coming from the exhaust pipe, most often in the mornings, even when its not cold outside!  Also, I noticed couple weeks ago, the fuel gauge would not go all the way to the top, to FULL!  I was just wondering, could any of these problems stem from using regular gas???  Oh is the car just falling apart, as older cars tend to do, especially since this car is 15 years old!  Please help!  I really love this car for the past 15 years (love at first sight), and I want it to last few more!!!

←

This topic has been debated quite a lot with about 50/50% for both sides. I use Sunoco Ultra 94 in my 01 ES & tried regular gas & I noticed a big difference between the two. I found I got better gas mileage, of course more miles per tank, smoother acceleration & a quieter idle with the premium.....to me it's worth the extra couple bucks per tank for the benefits you get. It all comes down to what you feel the car run's better on & if you want to spend the little extra for it. B)

[silvermate]

like Freak said......the octane/gas grade has been talked about many times in the past, just do a little search and you'll find everything you need to know, as well as all the members advice.

about the other issues you might want to start a specific topic question to get those exact problems addressed by the members. ;)

[VBdenny]

Permium fuel with it's higher octane burns much slower than regular(87). When you put regular gas in it causes the computer to !Removed! the timing so as to limit octane knock and possible engine damage. With regular your car will make a lot of noise and cetainly not run as well. I would personally use only premium because that is what the engineers designed the engine to use.

The white smoke indicates mositure. It is common for cars to emit some white vapors upon start up. If you start getting a lot and it appears when you are driving it usually indicates a blown head gasket. I have never heard of a Lexus V-8 having a blown headgasket so I would attribute the smoke to simple condensation.

I use the Chevron Techron in all my vehicles at each oil change. I buy the four pack at Costco for about $14.

[SKperformance]

moved to the general maintance section where their is tons of threads there.

premium gas for premium cars

i doubt you voltage problem is gas related likely alternator or wires being a problem

[Lexusfreak]

i doubt you voltage problem is gas related likely alternator or wires being a problem

←

Agreed sk. B)

[VBdenny]

I remember hearing from my dad that 90% of problems were electrical, and 10% were fuel.

[Lexusfreak]

I remember hearing from my dad that 90% of problems were electrical, and 10% were fuel.

←

Many times a problem is caused because of neglect or lack of maintenance as well. B)

[LovinItGoodLS400]

Well usually that is the case, but I take such good care of this car! Making sure everything is done on it and done by somebody respected in the field, not some cheap shop! I have gotten compliments on how new it looks, and they are always shocked when I tell them its 15 years old, it looks as if its 3-4 years old!

I remember hearing from my dad that 90% of problems were electrical, and 10% were fuel.

←

Many times a problem is caused because of neglect or lack of maintenance as well. B)

←

[Lexusfreak]

Well usually that is the case, but I take such good care of this car!  Making sure everything is done on it and done by somebody respected in the field, not some cheap shop!  I have gotten compliments on how new it looks, and they are always shocked when I tell them its 15 years old, it looks as if its 3-4 years old!

I remember hearing from my dad that 90% of problems were electrical, and 10% were fuel.

←

Many times a problem is caused because of neglect or lack of maintenance as well. B)

←

←

Excellent! Use the high octane gasoline & let us know if that helps or not along with the other suggestions fellow members have made. B)