bigmackloud

So the Sheetz gas stations around me recently installed pumps for E-15 and Flex Fuel. The flex fuel seems to run about $1 cheaper than premium. ($1.43 vs $2.43 currently)

Anybody running flex fuel in their 5.4L? Thoughts?

I know Flex Fuel typically gets lower fuel economy, but I average 12-13mpg any ways, so how much worse could it get, right?

Now I've also become rather fond of the tuner on my truck. I'm currently running it on the premium setting because I like the extra power and it gets a touch better fuel economy than the economy tune.

Anybody know if 5-star has a performance tune for the Flex Fuel? I'll dig up his email and ask.

johnday in BFE

iTrader: (1)

Not entirely sure what "Flex Fuel" gas is. Here in Michigan, we've been blessed with 10% ethanol for many years, doesn't even require a notice to the customer. We do still have the very rare non-ethanol gas, but it's hard to find.
Your 5.4 should run fine on the E15, I would think. In fact my truck, with the 5.0 runs E10 only, with a 5* tune. If your truck is a Flex Fuel, you can even run the E85 garbage, if that's what you're referring to as "Flex Fuel" gas.
Although I don't think I'd think I'd run any tune on it. IIRC, the octane rating is not there.
I found the E85 not worth the money savings, lost a lot of power and mileage. That was on a stock tune, and not really what you're asking, I think.
In a prius fine, with the E85, you're really not looking for performance there anyway, just a nice tree to hug!

azbubba

I specifically stayed away from wiki articles but did find this hotrod magazine article. Kind of refutes your opinion on the octane rating of E-85. I would suggest to the op to call your tune vendor and discuss this with them, I'm sure they can fix you up with the a tune to take advantage of the flex fuel.

johnday in BFE

iTrader: (1)

OK, what did you find different? My disclaimer was, "IIRC", regarding the octane rating of the E85.

But agreed, the OP should call 5*.

azbubba

Oh crap I forgot to link the article haha

http://www.hotrod.com/how-to/engine/...ernative-fuel/

johnday in BFE

iTrader: (1)

Ah, I see I was wrong on the octane, my bad. So, possibly the OP could run, say E85, and be alright. But like the article mentioned, ethanol has a lower amount of energy per gallon, or in other words, less Btu's per pound, so less power, but more consumption, hence my failed attempt at humour with the prius statement.

Ya, he really needs to call 5*!LOL Still though, I don't think I'll try E85 with my 91 octane performance tune, at least not yet.

Good article, thanks.

Sirikenewtron

E85 has an octane of 105 (+/- depending on the season) , you will get more power out of it but crap MPG's.
There are tuners out there who have e30 tunes which you get by using a mix ratio of e85 and 91 or 93 octane, what ever is the highest octane you can get of the two.
I know quite a few guys with 5.0's and ecoboost who mix the two with great results. Running the mix you up your octane yet don't totally destroy your MPG's
It's a much cheaper alternative to race gas

bigmackloud

Yea the local pump states a minimum of 51% ethanol, though typically it would be 85%. Im not sure how much the seasonal variance would impact a tune.

And yes my truck is Flex Fuel rated. Just as an fyi for anyone new to the subject, everything in your fuel system has to be e85 rated (pump, lines, injectors, etc).

Locally the e85 is about 40% cheaper than the premium Im currently running. So even if fuel economy dropped off 25%, I'd still be coming out ahead.

And yes, I sent an email to 5Star this morning. I'll share when I know more about the tune.

johnday in BFE

iTrader: (1)

Please do, it would be interesting to read what they say. It would be cool to run my 91 tune, just see where the performance might be. If it was to drop, say, to the 89 performance tune, and not drop off mpg's, it might be worth it to burn E85. But, I'm not gonna hold my breath! LOL