all of the Tundra tests you see in the commernials were run with premium, i would say try it both ways and see what works best for you

 

Thanks for the input. I have been running 87 without a load and 89 towing. I'll boost that up a notch and see how it works. I know my Jeep was very sensitive to octane rating when towing. Apparently the anti knock sensors really retard the timing and with it the power output.

 

I have not noticed a difference with octane when pulling a load, I pull a 9500 lbs trailer. Although I have noticed that I get better fuel consumption with 92 octane, weigh it out with price and it comes to a close race when deciding to go with 87 or 92, But as far as the power is concerend I have not noticed a difference in that with 87 octane

 

It doesn't make any difference whether you're towing or not. The engine is designed and the ignition timing is set to run with regular gasoline. The idea that you can get more power with high test gasoline when running in an engine with the compression ratios and ignition timing set to regular gas, is a long held myth. To get more power you have to boost the compression ratio and advance the timing according. To avoid pre-ignition (pinging) in that case, the gasoline burn rate must be adjusted to burn slower (higher octane rating) thus allowing the engine to develop more power. Super charging gets the same results i.e. more air/fuel mixture in the combustion chamber. If you aren't pinging, your octane is high enough.

 

That is a loaded question - and I suspect you are going to get widely varying opinions. It's been hashed out here a few times - with no real resolution. I'll throw my .02 in too - I ussually buy the cheapest stuff (of at least 87 octane), but about once a month I'll run a tank of premium through. Someone here said that premium was the same as far as additives, but it's only a couple of bucks more so I figure no harm, and possibly some good.

 

The difference between regular and premium gasoline is the stuff (once tretra-ethel lead) that is added to slow the burn rate and prevent pre-igition of the fuel/air mixture. All gasolines have it, only the premiums have more. Premium does nothing to clean up the engine, that is accompished by other means. And, it's in all grades of gasoline. Buying premium for an engine designed for regular is really a waste of money. It won't hurt the engine however, so have fun.

 

Doesn't Matter....just Use Name Brand Gasoline !!!

 

There were a couple of stations in Iowa that jsut got busted for selling E85 out of the regular unleaded pumps.... wonder what the hell they were thinking.

 

Try some avgas. J/K

 

^^^^yeah please do! J/K

 

There is a reason why Manufacturers state X vehicle needs XX octane rating. And TEDSTUNDRA got it right. Its all in relationship with compression leading to pre-ignition which leads to bad stuff! now I have actually heard running 92 on a regular 87 can lead to some carbon buildup since the burn is slower. So that might be one reason why not to. If you worried about cleaning out the engine like that use some gas additives that are made for that. Seafoam is a good brand that I like but you can read this article too which brings up a good point Auto Club Warns Consumers to Beware of Fuel Additives Claiming to Increase Gas Mileage - Auto News - Motor Trend anyways I dont believe there is a need to change gas when towing thats my .02

 

On modern vehicles with adaptive EMS from the factory, you may see an improvement with higher octane fuel. As mentioned before, ignition timing and compression ratio are key. I'm only on my 3rd tank of gas with the Tundra, and I haven't found any good information about the Tundra's EM yet. While the compression ratio is fixed, timing could be adjusted to take advantage of higher octane. Whether or not the computer is actually programed to do that is a good question. A computer reset when changing fuels might help it learn the new octane rating more quickly, and give you more timing to take advantage of it. ...or it might not.

Higher octane for a few tanks shouldn't hurt anything. If it doesn't work, its just a few more $$ per fill, and maybe a bit worse MPG. If you're getting knock while towing, and the computer pulls timing, then a couple of octane points will definitely help.

Are there any good logging tools (where you could monitor ignition advance?) out there for a Toyota?