JayDR6

HAHA ^ good idea! i always use 93, i once let my old lady use my IS and she had to be the cheap one to put 87 and the car suked the gas like nothing -_-

Pat5HKU19

I say Premium...dont take any chances it probably isnt worth saving a little with regular gas. Empty ur tank as much as you can and fill it up with premium.

dirkdiggle

iTrader: (1)

There has been a couple recent news articles I have read regarding this.

Regular Gas is safe and ok too use in most modern cars that claim to require only Premium.

The on-board computer recognizes if you use regular and will retard the ignition or timing to run safely on Regular.

Dont quote me on exactly what the Computer does but the moral of the articles was that it is perfectly safe for a car to run on regular fuel even if the manufacture says to run premium.

The car will not perform at 100% performance wise but will not mess you motor up by any means.

Justin727

With the ethanol they're putting in gas nowadays I wouldn't put regular even in my lawn mower. I sell more and more fuel induction services nowadays due to running conditions.
Seems that 87 causes more carbon build up more than ever. I never use to have detonation problems on my 2.7l 4runner until ethanol came out. I never ran 93 thru it as much as I do now because of it.

I wouldn't advise running 87 in the IS300. The computer will adjust for it up to a certain point and detonation will occur. Detonation is NOT safe. Detonation can lead to a few things that will mess up your motor. Burnt rings, piston damage, Blown head gasket, etc.

Now if I misunderstood your post I'm sorry. If you meant thats its ok just to run 87 thru the car once than that's fine as long as the car isn't beat on. Just be sure to the correct the issue ASAP