chadbobb

Ok, well i am just wondering what would happen if I put a higher octane gas in my 96 4runner. Would it increase power? Would i need to adjust someting to make it run like it is supposed to?

Also a side question, what are some websites i can buy parts from? Like lights and wheels and maybe some replacement parts.

rimpainter.com

If your 96 4R is in proper running condition, it will not benefit from higher octane fuel. So no, it would not increase power.

Toyota of Dallas has a good reputation around here. Look up Phil (Strap22).

Bobakazi

One way the higher octane will help is if you advance your timing. This will lower your power band, and give you better throttle response. I run my timing 16*BTDC, and 87 octane still works good for me. I have heard some guys run in the lower 20's, but I would assume you would need at least 92 octane all the time for that, otherwise lots of pinging. I only run super/premium when I go wheeling.

ebelen1

Since the post was made, I'll ask a dumb question.

I thought the reason that it didn't matter on octane for our 3rd gens is b/c we have a knock(sp) sensor that will retard or advance timing depending on the grade of fuel. If we use higher grade fuel (not that I'm willing to w/ these gas prices), wouldn't our timing be more advanced with higher grade fuel, resulting in better power (although probably negligible)?

midiwall

He's in a 96, the timing's all electronic, there's no distributor. "We" can only advance our timing with the use of a piggyback controller that fakes out the ECU. A very costly add-on for a few horses.



The knock sensor is there to let the ECU _retard_ timing when it hears knocking, it won't advance timing if it doesn't.

Higher octane fuel is slower burning, which means it will create power for a longer time in the cylinder. This can be a good thing, but you have to advance the timing to take advantage of it.

There's nothing in our fuel system that will detect the octane level of the fuel in the tank, so there's no way for the ECU to automatically shift the timing up.

tc

Note that higher octane fuel actually has LESS energy than lower. Because of that, it allows a higher compression ratio without pinging/knocking. The higher compression ratio more than makes up for the lower energy density of the fuel.

You want to run the LOWEST octane you can without pinging/knocking (well, at least the lowest you find at a quality gas station in the US)

Bobakazi

Oops. Sorry. I missed the '96 part.

chadbobb

what is an ECU?

mt_goat

ECU=electronic control unit (computer or brain for your engine)

wrenchmonster

Midi is right on target. You want a grass fire, not an explosion in your combustion chamber. Here's some more information:

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

Paul H.

Unless you run a supercharger, 92 or 93 octane is a waste of money.