What octane fuel do you run in your 1GR-FE?

What octane fuel do you guys run in your 1GR-FE?

I've run 87 for years, but recently while trying to debug a knocking problem (which turned out to be factory-installed spark plugs with 114,000 miles on them), I tried 93 (because go big or go home).

Today I went back to 87 and I feel like the engine is not as happy.

I realize that this could all be in my head.

I'm pretty sure the 1GR-FE was designed for 87, but does higher (say 89) help?

Thanks.

 

no, 87 if fine. If you think you got some bad, toss a bottle of octane booster and see if it drives better.

 

Do bottled octane boosters actually work?

 

Yes it does

 

Define "Work"?

They boost the octane but you won't be running 10s at the local drag strip. Lots of people make claims about higher octane results. Lots of tech info if your engine isn't knocking it won't do much of anything.

 

They’re designed to run 87, only the guys with superchargers need to run premium.

 

By “work” I mean cause a measurable increase in the amount of octane in the fuel.

 

When I bought the truck in late ‘08, someone told me that it was “designed to run on 89, but if you ran 87, the timing would automatically adjust to compensate.” Is there *any* truth to that?

 

not that I’m aware of, if Toyota wanted you to run a specific octane it would be posted on the fuel door.

 

Not sure if my engine has a 10.0:1 or a 10.4:1 compression ratio. 10.4 sounds a little on the high side for 87?

 

1GR-FE has a 10:1 comp ratio. Its designed for worldwide use and has no problem living on E10 87 octane (us calculation of (R+M)/2) )

With the use of various sensors on the 1GR and adaptive timing built into the ecu IT DOES alter timing and thusly can utilize more timing with higher octanes (hence the higher HP/TQ ratings on 91 vs 87).


All that stated, my truck gets the cheapest of E10 87 available... considering here in lovely CA that is currently hovering around $4.50-5.00/Gal ....

 

So when a higher octane fuel is detected (how exactly is it detected?) the cylinder ignition command happens sooner or later in the cycle? Thanks.

 

It detects when knocking occurs. No knocking, then advance timing. Knock detectEd, retard timing.

 

Knock sensors attached to the block of the motor in conjunction of a crank position sensor detects knock or the lack there of. The ECU will cautiously raise the KCLV (knock correction learn value) till knock is detected.

 

What results in more power: advanced timing (ignition before TDC) or retarded timing (ignition after TDC) and why?

Thanks again.

 

I ran 89 in my 2012 - I saw an increase in MPG vs 87.

 

in simple terms, advancing timing increases power. This is obviously limited and situational, though

 

I'm going to test MPG 87 versus MPG 89. What you saw is what I expect I'll find. Of course, I'll also have to consider $/mile and not just MPG.

 

The sooner you can fire the charge of air and fuel in the cylinder the faster it will start to send the piston the opposite way. For the most power fire as early on the compression stroke as possible without knocking. If you fired after TDC the piston would already be heading away from the flame front as it starts it's expansion and the engine would be losing power in that time because only inertia is driving that piston downward.

 

I think when I was doing it the difference was $0.15 / gal - at the current $0.30 / gal it may not pay for itself....

If you're experiencing any knocking then it's worth it regardless.