Will going to a higher gas make any difference towing with a V6?

[KidVermicious]

In conclusion...if you get better performance and better gas mileage by using a gas with a higher octane then what is rated for your vehicle...there are only 2 possibilities..

1) The gas you're buying is NOT actually the right octane rating. This is rare since most if not all states monitor this.

2) You have a problem with your vehicles engine...get it checked out.

Or, Toyota has built an engine that is designed to run on premium, but they don't want to market it as such, so they issue a bulletin that says use regular, but you can get "better performance" with premium, and let the ECU vary the timing accordingly.

Octane has nothing to do with potential work inherent in the gasoline, guys.

 

[UteRunner]

:rockthrow: Anyone else getting dizzy from the back and forth on this topic?

 

[scottji]

Or, Toyota has built an engine that is designed to run on premium, but they don't want to market it as such, so they issue a bulletin that says use regular, but you can get "better performance" with premium, and let the ECU vary the timing accordingly.

Octane has nothing to do with potential work inherent in the gasoline, guys.

+1 this.

No one is saying you can put 91 into a car designed to run on 87 and have it make a difference. We all know it won't. What we're trying to determine is whether the GR-FE is designed to run on 91 or 87. If designed for 91, then it will perform better on 91 than on 87. If designed for 87, then putting 91 in it won't make a difference.

Because Toyota's factory service manual says it's rated for 91, and because the Owners' Manual says that you can run 91 for "increased performance," I suspect it's rated for 91, but Toyota doesn't want to scare customers away to their Nissan and Honda competitors, so they advertise that it's fine to run on 87 (which it is, due to VVT and knock sensors). It also means that the engine is technically underperforming as long as you run 87 in it, but because these cars are somewhat overpowered to begin with, nobody really cares. This is my best guess.

 

[ClockWork]

+1 this.

No one is saying you can put 91 into a car designed to run on 87 and have it make a difference. We all know it won't. What we're trying to determine is whether the GR-FE is designed to run on 91 or 87. If designed for 91, then it will perform better on 91 than on 87. If designed for 87, then putting 91 in it won't make a difference.

Because Toyota's factory service manual says it's rated for 91, and because the Owners' Manual says that you can run 91 for "increased performance," I suspect it's rated for 91, but Toyota doesn't want to scare customers away to their Nissan and Honda competitors, so they advertise that it's fine to run on 87 (which it is, due to VVT and knock sensors). It also means that the engine is technically underperforming as long as you run 87 in it, but because these cars are somewhat overpowered to begin with, nobody really cares. This is my best guess.

Really?

 

[MikeInNH]

No one is saying you can put 91 into a car designed to run on 87 and have it make a difference. We all know it won't. What we're trying to determine is whether the GR-FE is designed to run on 91 or 87. If designed for 91, then it will perform better on 91 than on 87. If designed for 87, then putting 91 in it won't make a difference.

I agree 100% on this....Maybe we were saying the same thing all along.

Because Toyota's factory service manual says it's rated for 91, and because the Owners' Manual says that you can run 91 for "increased performance," I suspect it's rated for 91, but Toyota doesn't want to scare customers away to their Nissan and Honda competitors, so they advertise that it's fine to run on 87 (which it is, due to VVT and knock sensors). It also means that the engine is technically underperforming as long as you run 87 in it, but because these cars are somewhat overpowered to begin with, nobody really cares. This is my best guess.

The problem with using a lower octane then what the vehicle is designed for is - "What if the knock sensor FAILS". If it does and prolonged pinging occurs...you CAN destroy an engine. So if you ever hear knocking....back off on the throttle...I've torn into an engine that was destroyed by excessive pinging...two of the pistons had holes in them...

 

[scottji]

The problem with using a lower octane then what the vehicle is designed for is - "What if the knock sensor FAILS". If it does and prolonged pinging occurs...you CAN destroy an engine. So if you ever hear knocking....back off on the throttle...I've torn into an engine that was destroyed by excessive pinging...two of the pistons had holes in them...

Would the car throw a check engine light if the knock sensor went out? I know that on my BMW, for example, if there's a problem with the variable valve timing system ("Vanos" for the Bimmer), the computer will by default go into "failsafe mode" with the intake cam at full ret@rd and the exhaust cam at full advanced. I imagine the Toyota might do the same (and throw a code) if the knock sensor is out??

 

[450exc115]

Knock sensor fails chances are the ECU will pull all timing advance and run in a safe mode.

I've towed at 1700lb enclosed trailer using 87 and 93 octance gas (mutiple trials on each fuel) and found no difference in mileage or performance (less or more downshifts etc).

It use to be a rule of thumb that anything over 10:1 needed high octane, now that ECUs are smarter and faster with control that rule doesn't always apply..