4 Bangin, Fuel Sippin, Full Tank Challenge!

have yall noticed a mpg increase using ethanol free gas? or is difference it very minimal if any? there is a station by me that is always one of the cheaper stations and has ethanol free gas and i was wondering if i should make a point to use it.

 

IIRC winter blend is phased out slowly over several weeks. The refiners have access to long range weather forecasts for all regions, and adjust the amount of oxygenates that the fuel has in it during the switchover of seasons. The oxygenates cost more than pure gas, so it is to their advantage to use less if possible. I doubt if fuel in Mid to south Texas and Florida even have winter blend. Just my 2¢

 

It can be significant.
While Ethanol has a base octane rating of 118, making it a cheap octane booster that allows for more timing advance, it is stoich at around 9.5:1 compared to gasoline's 14.:1

If you had two identical engines, one tuned for gasoline and one tuned for ethanol, if the gasoline engine got 29mpg, the pure ethanol engine would get 19mpg, and it would put out 25% less power due to ethanol's lower BTU content.

That's comparing pure gasoline against pure ethanol.
Pump gas is only around 10%, but the computer still needs to add more fuel to compensate for the lean burn.

 

I understand ethanol's lower fuel content per volume compared to gasoline, and the resulting lower mpg numbers. But if ethanol is stoich 9.5:1 compared to gasoline stoich of 14.7:1, doesn't that mean more ethanol is added per volume of air compared to gasoline? If yes, wouldn't the additional ethanol balance out the otherwise lower power output of the ethanol engine? I just don't understand why an ethanol engine would put out so much less power if it's burning *a larger quantity of lower energy content fuel,* especially since an ethanol engine would be tuned to take advantage of the super high octane ethanol... wouldn't the power output be a wash for the most part? When I ask this question, I'm not considering fuel economy, only final power output of engines of equal displacement.

Consider this: high-compression gasoline engines put out more power than a normal compression engine of the same displacement, while burning premium fuel which has no more energy content than regular gasoline.

 

http://www.hho4free.com/gasoline_vs_ethanol.htm

 

I was referring to two identical engines. The ethanol engine only tuned to avoid the lean burn... not optimize power.
This is the only thing your engine's ECU can do when you go from pure gasoline to E10... dump in more fuel.
Flex-Fuel engines are able to compensate outside of the parameters of a normal engine, but the result of E85 is still significantly reduced power and economy.
This is following the parameters of the question as it relates to this thread.

Moving beyond issues pertaining to this thread and our Tacomas, for an engine designed and built to run ONLY on E85 or pure ethanol, then the design can compensate for that through greatly increased compression and timing. Ethanol burns cooler, so the engine is also more tolerate of a lean condition. There is a reason that racing cars use alcohol fuels. A properly designed alcohol engine can easily make more power than a gasoline engine of the same displacement... but it is also going to burn a lot of fuel.

 

with 285/70/17 on stock gearing and full armour i get around 20mpg consistantly. However if someone else were to drive my truck for a full tank the results would be far worse.

 

Yehaaaaa!!! Back over 19 MPG

 

Fuck the cold.

Love my truck.

It hates the muthafuckin' cold.

 

That's pretty good Kase given you are sitting higher than most of us. 400 miles in my truck is decent.

 

I also understand that the E85 engines are more expensive to build (high compression engines).

 

About 10 or so years ago, I started to fill my Jeep TJ up at a gas station that was on average 5 cents a gallon cheaper. For two straight tanks, I got around 12 MPG. Then I read in the newspaper that this station was selling E85 on unmarked pumps and many people were having problems with their cars. The problems ranged from bad MPG/no power to a few people had $1,000 or more repairs. Took about 3 fill ups to get back to normal MPG. That E85 sucks and if the ECU can't handle the change, you may have to completely drain the fuel system and reprogram/recalibrate everything.

 

I got my 5-lug in the middle of winter (January) and have been making regular highway trips 600km+ every couple of weeks since then. The PO used it as a service truck so it never saw much highway action prior to me.

My first trip (627km on January 22nd) got me 23.55mpg
My most recent trip (638km on April 17th) got me 27.41mpg

This is 98% highway driving through mountain passes (Calgary, AB to Kelowna, BC)

 

Is that imperial gallons?

 

Nope. US.
The app I use (Road Trip) can automatically convert from l/100km to MPG.

 

Doing well then.

 

I see you've got an all-time mileage of 30.3mpg...what's your secret???

 

Wads cheats.
He's a hypermiler.

He only uses his engine to drive TO work. It's all downhill coming home.

There's a few things you can get away with on a manual that'll damage an automatic.

 

Latest tank, 575 miles on 19.409 gallons for 29.6 mpg.

Thought for sure I'd be able to break well into the 30s but we had a cold snap with lows in the teens and 34.9 inches of snow for the month.

Still didn't need 4x4

I only use my engine to accelerate, then it's off while coasting.

Here's some techniques.

http://www.cleanmpg.com/forums/showthread.php?t=1510

 

I hate you 5 luggers. I traveled about 30 miles to meet someone to sell some Jeep parts. I was heading into a 30MPH+ wind and the instant MPG on the ultra guage never went above 21MPG. When returning, the instant MPG was in the upper 20s (27-30) most of the time. The trip was on two lane roads at 60MPH for about 25 miles each way.

What sucked was the gas was 25 to 30 cents a gallon cheaper than around my house. I filled up and averaged 19.8MPG.