GoGiantsNJ

If this was discussed in the past,please excuse me.I'm on this forum now for a week or so.

I use Shell 93 octane on my Wife's new IS-250-AWD. It seems to be a good match for the engine. Does anyone get great performance from any other brand of fuel? I see that Lexus recommends 91 octane, but has anyone tried mid grade 89 octane?

I realize it's probably not good for the knock sensor to use regular 87 octane.
Just wondering.

GiantsFan

iTrader: (9)

Damn I wish I had 93 gas over here in CA lol.

Use 91+ octane. Thats what it says in the manual and by the gas cap.

ps - the giants in my screen name is for the SF Giants, in case you were wondering

Tarrant64

I've used 89 and 91 - no real difference.

Reality is cars these days can adjust for higher/lower octanes. There's a recommended use for many but you can generally use whatever you feel is best (ie. willing to pay for).

Also - there is a long thread in here somewhere where this is discussed at length. I can tell you I know someone who has a Mazda CX-9 (?) and it required premium. This person did not use it and after about 100 miles on the tank the car broke down. Now, that's just an example from Mazda - I do NOT believe that Toyota/Lexus makes engines that act in that manner for not using the same octane. I've driven over 1,000 miles 89 and didn't have a problem ('11 IS350 AWD).

EDIT:
I should also mention that a majority of the time I do fill up with 91.

bob4256

iTrader: (17)

Use premium and dont bother using anything else. The difference in price is not that much and you will avoid engine knocking in the future

Joshohoho

use 91+. Use anything lower and we'll see you making new threads about your engine making knocking sounds

knguyenk

I fill my IS 250 AWD with 93 octane or anything above 91. The price difference between 87 and 91/93 isn't justified to run a lower octane than what the manufacturer recommends.

jbone29

iTrader: (2)

Nothing but 93 since I bought my 350. Runs like a beast all day long!

Initial G

iTrader: (38)

Used nothing but 91 octane since day one. Didn't bother using anything else.

OP can do a search, there are countless threads concerning this topic. Good luck.

Sango

iTrader: (10)

91 mainly. Once in a blue moon I may get 94 (Supreme Plus at Chevron Canada).

phanotos

Only 91 octane. If I stay with one brand too long, I notice MPG going down a little, after I switch to a different brand, it goes back up. I alternate between Shell and Chevron.

Fizzboy7

Do what the factory recommends. The engine is tuned to run on 91. Lower octane means reduced efficiency and reduced performance. I once tried 89 and the car ran noticably slower and got worse mpg's- a waste of savings at the pump. Plus, with the 250's tendacy to have clogged injectors, you want the best firing and cleaning in there as possible.

NQR89

I've always ran premium and nothing below. I usually alternate between shell, chevron, and mobil depending where I am.

GoGiantsNJ

Thanks all. I'll stick with the Shell 93.It's only 25 cents more per gallon than regular here.
GiantsFan I kind of figured you were an SF Giants fan seeing that you're in Cali.
My Bro-in-Law who moved from NY to San Fran is a traitor now.He said he likes the Giants instead of his once loved Mets. LOL
I'm a Yanks fan luckily.

Kappy550

iTrader: (4)

In Lubbock, Tx where I go to school there is only 91 octane so I run that but when I go home to the Dallas area I get the pleasure of running 93 octane

nosurprise

iTrader: (1)

Below is the long thread that discuss about this. The guy started thread pretty much saying he always used regular gas on his car. Pretty much all views are covered in there. I'm more in the "it's probably OK but probably degrade performance and probably shouldn't bother" camp. It got little technical too with numbers and stuff

https://www.clublexus.com/forums/is-...gas-is250.html