actually the Tc has a 9.6:1 compression ratio, if we had 10.5:1 that would be pretty cool, because of more horsepower naturally

 

Actually shangtsung drives an xA. The xA has 10.5:1 compression.

 

an octane is an eight chained hydrocarbon. the 87 is the actual percentage of octane per 100 parts. since an octane can handle high compression well, it's recommended you use a higher octane in high compression engines. the fact is, the 87 rating is an average rating. you might have some parts at 91 and others at 85, so you mix the two to get 87. 87 parts might be stable under compression but the the other 13 parts is not, that's why you dont use it in high compression engines.

high compression = NEEDS 91 octane or higher
low compression = NEEDS 87 octane or higher

so use the approriate type of fuel for your engine. our tC's are not high compression engines, so use the 87 octane.

 

http://auto.howstuffworks.com/question90.htm

 

Say for instance you were pushing 300whp on tc with a trd s/c and mods would higher octane be necessary?

 

Wow. You're all wrong...

89 and 91 DO make a difference.

89/91 and other higher octane fuels give your car better acceleration and higher output.

The money is extracted from your wallets and/or pocketbooks, therefore reducing the overall weight of the vehicle when you're in it. However, those of you who use credit or debit cards at the pumps won't see much of a performance difference and you should stick with 87.

 

Someone anwser my question please

 

yes. the trd sc reccomends 91 doesnt it?

 

More insite on this question please

 

http://www.trdusa.com/tcsupercharger.asp

THE FUEL SYSTEM BACK TO MAIN PAGE

Larger 400cc fuel injectors are included to deliver the extra fuel needed without requiring increased the fuel pressure. No other modifications to the fuel system are required. Premium 91 octane fuel is required.

 

Thanx!

 

does octane levels matter when red lining?

 

LMAO I love it!!

 

haha

 

ive always gone with 91.

 

Yeah I agree with the 87

 

I totally agree man.

:D:D:D

Anyway. "Search" should be the first thing on the site that pops up, at a 640x480, at least. And there are some things that someone should have their license taken away for. One is telling someone else that 91 gas makes a difference in an 87-recommended engine. Another is filling diesel in your tank.

 

it true cuz I've been testing on both grade and notice a little difference. higher grade give a little better mileage but not alot and it clean the engine also. I believe for stock engine who have higher mileage on their engine should have premium every once a month or every two months to keep their engine clean instead of having to buy the different kind of brand that has chemical to clean the engine. Also people are right that people who modified their car with FI should use higher grade. I just did a little calculation and notice a little difference that all but it not a big deal of having premium fuel.

 

when you run "richer" that means you're injecting more fuel than what's necessary to maintain a proper a/f ratio.

it doesnt change your mileage unless you needed higher octane to begin with for a higher compression engine.

are we seeing similarities here? turbo? high octane? na high compression? high octane?

HMM.

 

I use 1/2 87 and 1/2 89 octane at Shell.I'm getting right now 40-44 mpg with my mods .Today I got around 50mpg but,don't listen to me I'm that wierd Scion Xa guy,lol.