that'd make, ideally, 88octane gas, which would not make 6mpg difference :D its your driving.

 

Yeah ,maybe it's cuz;I use nitrogen in my tires also and watch them like a hawk also.I do not submit to Scion's recommendation of 29 psi on the tires also.Thru my mods also I have been getting on average 43-48 mpg .So far I have beat 4 out of 6 hybrids in mpg test but,I'm wierd u shouldn't pay attention to me,lol.

 

it's true that if your car isn't knocking then you don't need higher octaine. however, these engines have 11:1 compression which is very high for 87 which tells me that they have seriously de-tuned the engine and more than likely have a knock sensor installed (i'm not sure about that but my other cars have it) so if you run 87 you will not hear pinging because the computer has retarded the timing.

you will see a hp increase and mileage increase if you run higher octaine gas and advance the timing a few degrees at the same time.

and IF these cars do have a knock sensor, it's entirely possible that you can run 91 octaine and simply reset the ecu which would put the timing back to where it was before the knock sensor retardrd it.

this is all just a guess with these cars but the fact remains we do have retarded timing for 11:1 compression. :-/

 

The 1NZ-FE does have a knock sensor, as does the Camry engine in the tC.

I've used 89 in the past and it seemed to advance the timing in my xB. At least it seemed to run smoother with a bit more power and slightly better mileage. But there's always the risk of combustion chamber deposits, which WILL gradually increase your car's octane requirements. Especially if you do a lot of stop-and-go driving.

If your car just won't run right with 87, try running Techron Concentrate in your next few tanks of gas, then switch to a quality regular unleaded.

 

read it again, or unless they printed you a differant version.

 

my choices are 86/88/91... 88 it is...

 

i have never heard anything so true in my 20 years of existence!

 

....

 

I tried 89 and it made no difference, at all. Stick with 87.

 

the only possible difference is in chronic buildup of various deposits in the engine.

 

Do you think 89 is a good idea for simply running an intake and exaust?

 

no

 

so we now have 87/88/89/90/91 octane in california if we mix the grades together.. wtf!

 

tC owners, try 87 than try 91 than go back to 87 and see if there's any difference.

Some of u say it's "exactly" the same (except the pocket is lighter - that's a good one I must admit), but until you've tried it yourself you have no idea.

 

I'm going to try an 87 this week and see how that works.. im thinking it makes a very minute difference other than the pocket book.. esepcially on a 1.5ltr