E85...any reason Not to use it?

[SnowFish]

2009 Yukon
5.3 with AFM disabled via Range
150,000 miles
Oil changes at 3000 - 4000 miles. Mobil 1 5w30 full synthetic with Nape gold filter.
No leaks. No lifter ticks.

On my second full tank of E85.
Have not noticed any mpg drop. Average still hangs at 14.5 mpg.
Power seems good. Engine is smooth.
I like saving $11-$12.00 per fill.

Is there any reason to Not continuing to use E85?

 

[randeez]

unless you were using absolutely trash fuel before you should see a drop in mpg (the dash average may be over thousands and thousands of miles it may not budge for a while) watch the instant mpg for a better comparison, on the highway my mpg would be within 3-4 around town is where i would really notice a drop.
the cost per per mile VS premium you will see a saving, if youre content with running 87 then you may not see a savings.
with that said, it burns a lot cooler and cleaner that gasoline...the ecm will take advantage of the higher octane, my truck with no cats, full 4" with straight thru mufflers has no exhaust smell when i run it. keep up with the oil changes for sure every engine experiences blow by, that is evacuated by the pcv system, with ethanol the blow by can dilute the oil if extended really long -

Also @swathdiver has a pretty long running thread for e85, different % mixes, opinions, etc. in the performance section you can check out

 

[Fless]

You may experience more starting difficulty with E85 in cold temps. Other than that be sure that you have a Flex Fuel vehicle.

 

[SnowDrifter]

Worth nothing that e85 ought not be used if you don't put many miles on your vehicle. It's hygroscopic

 

[SnowFish]

Worth nothing that e85 ought not be used if you don't put many miles on your vehicle. It's hygroscopic

Makes sense. Yet wouldn't E85 be less prone to phase separation than E10? More alcohol to absorb more water.

 

[intheburbs]

Well, physics says your mileage with E85 will be about 75% of your mileage with gas. Your truck isn't magic. E85 has fewer BTUs per gallon, so the engine has to burn more of it to do the same work.

So the reduced cost will be offset or, more likely, completely canceled out by your decreased mileage.

On the upside, E85 has a higher octane rating, so the engine should be able to wring out a little more power on E85.

 

[SnowDrifter]

Makes sense. Yet wouldn't E85 be less prone to phase separation than E10? More alcohol to absorb more water.

I'd think less prone as it would take more water to saturate the e85 to the post where it's no longer miscible with gasoline.


Biggest issue w/ the water content is corrosion and burnability

 

[SnowFish]

Good point. Next fill I'm back to real gas. Unless I'm able burn through it, in a day, towing.

 

[randeez]

Solid plan

 

[swathdiver]

Is there any reason to Not continuing to use E85?

Not really. It allows the engine to make more horsepower and torque and if the cost is low enough, can be less expensive to run. It certainly burns cleaner too. I've seen no ill effects with the truck sitting in the driveway for 1-2 weeks with a 1/4 tank of E85 on board. Until recently, that was often the norm.

Now for the kicker, I've just completed my 12th tank of E30. E30 costs less than 87 octane and delivers more mpgs than 93 octane gasoline in my truck. If E30 isn't available you can make your own. Soon as the light comes on pump in 5 gallons of E85 and 17 of gasoline for those of you with the short trucks. This will give yield an alcohol content of around 20-22% and the octane rating will be 91 if you use 87. If you pump in 93, it will jump to 95.

If you have a 31 gallon tank and wait for the light, pump in 6 gallons of E85 and 20 of gasoline. If you're starting out with a higher alcohol content you can get the R+M octane rating up to 96 with these mixes.

For those trying this for the first time, you can't just fill up once and expect the full benefits, you've got to give the motor AND transmission time to adjust and it usually tanks at least 2 tanks and usually 4 or 5.

If you're running around town any form of E85 is great but for long trips you want the range and availability which isn't as easy as just picking any exit as a desire to run long distances on Ethanol requires thorough planning to identify stations that carry it and will be open when you pass through.

I could get from the Treasure Coast to Houston, Texas now on E85 if I wanted. But man, this E30 is even better for endurance while still burning clean through the motor.