Toyota Tundra Forums banner
1 - 9 of 9 Posts

·
Registered
Joined
·
69 Posts
Discussion Starter · #1 ·
My tank has a quarter left since it left the dealer lot. I know they put the reg 87 unleaded when they filled that up...I always use 87 as long I don't hear a knock...so what do you use on your baby?
 

·
Registered
Joined
·
528 Posts
87 just like the book says
 

·
Registered
Joined
·
81 Posts
I like to run a tank of 93 through mine about once every couple of months to scare the crap out of it. Keep the truck guessing, that's my theory!!!
 

·
Registered
Joined
·
764 Posts
The higher the octane rating, the less the volatility. Lower volatility is necessary for higher-compression engines to keep the fuel/air mixture from compression detonating (like a diesel) before the spark plug fires. Higher octane rating does not mean more energy in the fuel, it just means it's going to take higher combustion pressures without detonating. The most optimum and efficient octane for a given engine is the minimum specified value by the manufacturer (in the case of the Toyota 5.7L that is 87).

If you really want to "scare" your engine (reusing a previoulsy posted term here) you could add about a pint of Jet-A fuel, like jet and turbine aircraft burn in their engines, every month or so to a full tank of gasoline (it is basically clean Kerosene with lubricating additives). Most of the cheaper (but still expensive for what they are) fuel system cleaner bottles for sale at your local auto parts warehouse are basically Jet-A fuel. Cleans and lubricates things up nicely. You can take your 1-gallon jerry can to the nearest airport and buy a 4-month supply of Jet-A for a lot less than the auto parts store (probably $2.50 or less for the gallon). It is stable and stores very well (unlike automotive gasoline which doesn't store well over time). In reality unless you are in Mexico burning Pemex automotive blends I wouldn't add Jet-A to a daily driver's tank but every 6 months at the most.
 

·
Registered
Joined
·
172 Posts
It seems that when they run this in the news on accasion, they usually say you may here knocking sometimes when you under a load or accelerating up a hill even if you run the recomended octain. I never wanted to here the knock, so I always ran 89 in my vehicles. Also they say that more addatives (injector cleaners, etc...) are in the higher octain fuels. Correct me if I'am wrong.


The most optimum and efficient octane for a given engine is the minimum specified value by the manufacturer (in the case of the Toyota 5.7L that is 87).
Does this mean you would get better miliage out of 87 than you would 89, or the miliage would be the same but cost less?
 

·
Super Genius
Joined
·
920 Posts
On my 2002 Tacoma 2.7L 4x2 PreRunner I always used 93 or 94 under the impression that it had to be better and would not harm the truck, so for the small price difference why not? I ran that truck for 4 years, about 40% local and 60% highway, and 106,000 miles later it was still averaging 20-21 miles per gallon which was the same since the day I drove it off the dealer lot.

All the forums I read on the new 2007 Tundra recommend using 87 so I have switched to 87 and have not noticed any knocks, pings, or other negative affects. I am still at 700 miles total with 60% local and 40% highway and so far the truck is averaging about 16 miles per gallon. I am hoping the MPG will climb up to about 18-19 on average once I do some more highway driving but perhaps this is a dream. Even if it stays at 16 I will be happy. The sheer power of the truck and fast acceleration is awesome.

On the way home today a Chevy 4x4 passed me in the right lane and raced his engine on the way by. I had been idling at 75 mph or so but when he shot past me I let him get about 10' in front of me before I down-shifted into fourth and punched the Tundra to sail by him at about 85 in no time. He did not try to pass me again. This driving behavior is very unusual for me but something about the Tundra 5.7 L V8 just dares you to take advantage of the power once in a while... :)
 
1 - 9 of 9 Posts
Top