msdelexus

Hi,

I've been using premium fuel eversince I had my 2003 es300.
My son often times uses the car and puts in regular fuel.
Will I have problems with the car's performance if I switch to regular grade fuel at this time? My es300 has about 85k miles.
Thanks!

GSteg

iTrader: (15)

You shouldn't have any problem. The engine was designed to run on 87 octane anyways.

xspsi6

iTrader: (31)

Yes running premium on an engine that was ment to run on 87 could do long term damage due to exsessive carbon build up and the slower burn times of premum will actually decrease performance and increase emissions.

JamesBond1

Wow, everything you just said is wrong. You should read up on things before you start typing.

xspsi6

iTrader: (31)

Cool thanks for telling me I am wrong, I tune cars for a living so I guess I better go figure out wtf I am doing first.

So should I put 87 in my 600whp supra then? Please let me know because you seem to know it all!

JamesBond1

Your question now is the opposite of what you said earlier. Earlier you said "running premium on an engine that was meant to run on 87 could do long term damage". and now you're asking it again, just the other way around. Running premium on an engine that was meant to run on 87 WON'T cause long term damage. You also said “premium will actually decrease performance and increase emissions”. Premium will actually INCREASE performance and LOWER emissions.

Listen, just because you "tune cars for a living" doesn't mean you're well educated in the field of automotive. For example, I know car mechanics, who have 20+ experience, that have limit knowledge in some of the most common and easiest areas and/or make stupid decisions. I know a police officer that got fired for making a stupid mistake. And the best example of high status failure is your previous president. What I'm trying to say is: just because you "tune cars for a living" doesn't mean you're smart about the decisions you make and doesn’t mean you know everything about anything, for example: fuel.

I don't care about your supra or you, for that matter; nor do I want to argue. I was simply stating that what you said was wrong and I stick to it. I'm not here to make enemies...Let's just agree to disagree and let others think for themselves.

GoodRevs

Subjectively speaking, There is a noticeable difference in performance between premium and regular in our 03 ES.

01LEXPL

iTrader: (10)

^^ here we go.... lol

BoostedE21

When you're tuning your ECUs, you probably tune them to run on a specific octane rating, and ONLY at that octane rating. Modern stock ECUs are more flexible. Knock sensors can pull timing automatically if detonation or pinging is detected, and since octane level is sort of "flexible" (you can legally fill a container of 93 with 91 and sometimes lower if the station is low and that's all they have), that's a necessity.

So while on your specifically tuned settings running a lower than specified octane fuel might be detrimental, in a general sense it is not.

I have been running 87 on my ES for a while now. It's SLIGHTLY slower, but honestly, in normal driving I haven't noticed much. Fuel economy dropped about 10 miles to the whole tank. Since the price difference between regular and premium is 30 cents per gallon here, that's a sacrifice I'm willing to make.

xspsi6

iTrader: (31)

First off I did not ask a question and second if you use premium which is a slower burning fuel you will create carbon build up faster because you don't have the compression or timing avl in a stock ecu to take advantage of the much much slower burn time of 93 oct fuel so yes it can potentially do damage over time and it will increase emissions as the combustion cycle is now burning slower due to the fact the factory ecu can't and never will be able to adapt properly to take advantage of the high oct fuel you are using thus creating way more unburnt fuel to help clog up converters etc

You simply can't properly ignite the overly rich mixture when using premium fuel unless you have a standalone ecu that has adjustments for timing and air fuel ratio per load.

But go ahead and keep throwing premium in a car thant was ment to run on 87 not my money!

Btw we are getting a good laugh here at work at the expense of this thread

JamesBond1

Yes you did...You asked if you can use 87 in your non-turbo supra.

True, it’s not your money, but it won't damage your engine, won't increase emissions, and won't decrease power is what I'm trying to say. You can’t seem to comprehend what I’m trying to explain.

Good, I'm glad you and your co-workers are laughing because in the end, I'm laughing.....at YOU!

p.s.... you ALWAYS seem to spell the word "meant" incorrectly (even in your past post) you spell it ”ment”. I do hope you can tune cars better than you can spell ahaha. Oh and good luck getting all that WHP to hook, in your supra.

BoostedE21

JamesBond1

There you go xspsi6. It says "Select octane rating 87 or higher. For improved vehicle performance, the use of premium unleaded gasoline with an octane rating of 91 or higher is recommended."

That proves my point: that using higher octane WILL NOT damage your engine and WILL indeed boost performance as per the Lexus book says. Also, it will decrease emissions. 87 will do just fine but 91 won’t hurt your engine like you keep on saying it will.

Thank you BoostedE21. You have made proving my point a breeze.

01LEXPL

iTrader: (10)

<grammar **** checking in>

JamesBond1

Ahaha. What's up 01LEXPL, how have you been? You're enjoying our chat, I see.