toeb

any time i run lower than 93, it will throw a cel for lean fuel mixture.

Shawnmack

I always use 93 octane. IMO it makes the engine run smoother.

swat1727

iTrader: (2)

Octane relates to gasoline’s volatility factor in the combustion chamber, and has nothing to do with performance, so pouring premium into your base Corolla is money wasted. High-performance engines, on the other hand, need higher-octane fuel because the combustion chamber environment is much hotter than normal. Using premium fuel reduces pre-ignition, which can damage valves and pistons if allowed to go for long periods of time.

kit cat

iTrader: (6)

20cents more / gallon, tank takes about 18gallons, 3.60bucks more per tank....

I'll take premium and save 4bucks somewhere else like not drinking Starbucks.

swat1727

iTrader: (2)

WORD

LexFather

x2

Lexus RECOMMENDS Premium. We have been down this road since I've joined this forum.

Lyrical

iTrader: (8)

If continually using 87 gas will eventually cause the ecu to adjust itself to the lower grade gas, will continually using 91 cause it to readjust itself??

19psi

yes. as long as the ecu is tuned to run optimally on 91+. if the ecu is a regular grade tune, then it wont do anything by running 91+. however, if it's a premium fuel ecu, then it will gradually give back timing as long as it doesn't see knock until it's on the max perforamnce timing map. or you could reset it if you know you're going to be using 91+ by just disconnecting the battery for a few minutes. this automatically places the ecu in the default high octane, full timing, factory spec mode.

3UZFTE

Why go agianst what Toyota recommends, they wouldn't just tell you to do something if they didn't need to, i'm sure they have no incentive to just slap a "premium fuel only" on. All the ecu is doing to control the lower octane mixture is retarding the timing, via the knock sensors. You will see a decrease in performance as well as efficiency. Good luck with 89, i'll stick with my tier 1 premium.

TonyO

I can almost hear it knocking right now *ker plunk ker plunk ker plunk tinker tinker putt putt ssssssssssss*

luxaro

iTrader: (2)

i always use the highest grade. the difference is only $3-5 per tank. save it somewhere else.

iGOTlexy

iTrader: (3)

yeah my dad use to do that in bmw and I always freaked.

Solution: GIVE YOUR PARENTS THE CAR WITH A FULL TANK

movaaa55

thanks to all with the replys. im pretty convinced after seing mycars performance during the past two weeks that premium is the way to go. with 87 octane i got burned in a drag race with my friend's 97 jeep Grand cheeroke V8 4.0L. ive noticed an extremely long delay with acceleration. but in normal driveng conditions it seems fine. but what if i add octane boosters, like 108, along with premium. as well, what engine cleaners, like fuel injector cleaners, do you prefer? thanks movaaa

ROBONY

Good thread.... NY prices for premium $4.09 and still going up.

Rob

LEXUS_KID

iTrader: (4)