Anyone running 15% Ethanol 88% octane

It is significantly cheaper (40 cents a gallon). Wondered if anyone has any experience with it.

 

I ran an E85 tune and fuel with my Gen 2 Raptor for a short period of time. Peak power and responsiveness was very noticeable. But from an economic standpoint it didn't prove worthwhile even when driving very conservatively. While the E85 fuel is cheaper, it has a lower energy density than the 91 octane I run otherwise. So I noticed a 15-20% loss in fuel economy when driving similar mannered to a non E85 fill up. The price difference didn't make it worth any difference in the end, and expected higher maintenance costs to be associated with the E85. So do some of your own research and come to your own conclusions, as par for the course with this forum there will be some very strong opinions that disagree with me, anecdotal and otherwise. I have no experience with E85 or other "Flex-fuels" in my Tundra thus far.

 

I could see a difference between the 91/93 octane vs the E85. I just can't appreciate the same when comparing the E85 vs 87 that has up to 10% ethanol.

appreciate your insight. I am assuming, since the gas cap clearly indicates that the E85 is an option so it is safe to use ??

 

Yes it is safe to use E85 Flex Fuel if the gas cap and owners manual indicates so. I do not have any experience with it in the Tundra though, hopefully someone will chime in soon.

 

It should be just fine and will be compensated for with the fuel trims. Vs 10% ethanol, the AFR only needs to change 30% of 5%, so barely at all.

The engine may actually like the added ethanol to some degree. It will cool the air charge and cylinder slightly more as it vaporizes.

 

Owners manual says you can use up to 15% ethanol.

 

From all the race engines I have run, engines like 10% ethanol much more than 100% gasoline from a resistance to knock standpoint.

 

You’re asking about E15 gasoline with 88 octane rating right? You can run it and probably should if it’s cheaper. You will see a slight decrease in fuel economy but it will still cost less than running E10 87 octane.

You can’t run more than E15 in this engine so E85 is out of the question without a flex fuel sensor and a tune.

 

In my 2014 tundra had the flex motor something that not all 5.7 liter Tundras had. I was told that if I used e85 fuel I would have to change the oil at 5,000 miles. But if I didn’t use e85 I could extend the oil change interval to 7,500. I only used e85 one time and the MPG dropped by 20 percent. After that I never used it again.