what fuel is safe?

[Barrman]

That app is great for finding it but the prices vary tremendously.

There is a gas station/travel shopping center chain called Buckee's in Texas and now other points east. The one in my town is a little baby Buckee's with only 28 pumps and normal fuel. They have a mega store 26 miles away in Bastrop that sells ethanol free 90 octane for about $.20 more per gallon than ethanol mix 87 octane. That is a great deal since it is cheaper than the ethanol mix premium by a good bit even.

Colton was outside of Dallas a few weeks ago and stopped at a Buckee's to get ethanol free and it was $1.00 per gallon more than ethanol mix premium. Same company crazy price difference. Another store 35 miles in the other direction claims on the Puregas app to have ethanol free but it is 87 octane and $.50 more per gallon than premium mix.

Basically, don't rely on that app if you have to put ethanol free in to continue your journey. Unless you can call or some other way verify what octane it is and what price it is. Plus, if they actually have any that day.

[Barrman]

Oh, both my ancient BMW 525 Touring and Jennifer's old Outback get 10-15% better mileage with the ethanol free and run so much better since they were made before the mix was required by law.

[kwai]

Of course they run better. The 10% ethanol in the mix gas has less energy than the gas it replaced. So a gallon of ethanol mix doesn't have as much energy as the gasoline it replaced. Therefore, ethanol mix gets fewer mpg's than pure gasoline.

Science baby. It's what makes the world run.

[brute4c]

Alcohol has about 55% the btu output of gasoline...so Kwai is exactly correct...the higher percentage of alcohol, the more power you take away from the gasoline.

[ColoradoSpringsRob]

This got me thinking that someone likely has put together a calculator to show some of the costs/benefits of ethanol (e85) vs. gas, and lo and behold, here you go: http://www.yellowhose.com/e85_calc.html

What this does not calculate is the detrimental costs of ethanol, and on and on...nor does this calculator allow you to select different octanes (e10, others) to determine how each stacks against the other.

[kwai]

If ethanol production wasn't subsidized and mandated to be used in gasoline, it wouldn't be used at all.

[ColoradoSpringsRob]

To your point Kwai...

'Ethanol’s lower energy density leads to worse gas mileage, which is why using E85 (E85 is 85 percent ethanol) in cars with a fuel system that accommodate it is usually a bad idea. The math carries to E10, which has up to 10 percent ethanol. A gallon of E10 has 96.7 percent of the energy in one gallon of gasoline, according to the DOE’s Alternative Fuels Data Center.' - (taken from https://www.cars.com/articles/2013/1...worse-ethanol/)

[kwai]

My 2000 grand cherokee (V8) gets more than 10-15% lower mpg (18) with ethanol than it does with pure gasoline (21).

[Barrman]

I think that 3.3% drop in energy is a bit low.

I know this thread started out as a way to make a 50 year old truck work on todays fuel mix. But, anytime we can include science, math and physics. Plus a good helping of regional politics in a thread. We all win.

[kwai]

meh. Go diesel.