The truck would be a 2017 Toyota Tundra V8....What would be the advantages vs disadvantages of buying a truck designed for Flexfuel?

You don’t have to run flex fuel in it. In fact, you’ll lose a little horsepower and fuel mileage running it. Being a flex fuel vehicle just means that you can run that fuel if you choose to without harming the engine.

I wouldn't look for that but wouldn't care if it was made for flex-fuel.

I see no advantage but that's just me. Automakers use it as a way to meet some government numbers.

The problem with flex-fuel is as the alcohol content goes up, power and MPG go down. Not by much but they do. Often any savings on fuel is negated but the loss of MPG.

If I had a flex-fuel vehicle I would never use it for the above reasons.

I don't see a downside.

The advantage is that as a last resort you can run that 85% crap.

I wouldn't run it unless it was a last resort.

Did I mention last resort?

My 13 tundra was flex fuel. I never ran a single gallon through it.

There is an equal or greater loss of efficiency related to the minimal savings in flex fuel cost

Advantage is you get a 'hardened' fuel system built to resist the corrosive effects of alcohol, and the option to run moisture absorbing E85 that sat in the hot sun for who knows how long if you have no other choice.

E85 fuel does have lower efficiency as already stated, but it does not result in lower power than regular fuel. It’s actually the opposite, you get more power from E85.

https://www.google.com/amp/s/c...power-than-gasoline/

quote:

Originally posted by Largefarva:
E85 fuel does have lower efficiency as already stated, but it does not result in lower power than regular fuel. It’s actually the opposite, you get more power from E85.

https://www.google.com/amp/s/c...power-than-gasoline/

You’re only going to see HP gains in Supercharged/Turbocharged applications or vehicles that call for higher octane fuel with E85.
https://www.dragzine.com/tech-...gs-you-need-to-know/

I don’t know all the details but what you said makes sense....where I first heard about E85 was on some F150 forums when I had a 2011 with the ecoboost engine. It became a hot topic for a bit when some guys were seeing if there was a way to run E85 in their ecoboosts. So that’s where I first heard about it. But even in the article you posted it says that naturally aspirated engines can benefit from E85 because of the cooling effect which creates more power....it just wouldn’t be as much as with a turbo or super charged engine. Or am I reading it incorrectly?

quote:

Originally posted by PowerSurge:

quote:

Originally posted by Largefarva:
E85 fuel does have lower efficiency as already stated, but it does not result in lower power than regular fuel. It’s actually the opposite, you get more power from E85.

https://www.google.com/amp/s/c...power-than-gasoline/

You’re only going to see HP gains in Supercharged/Turbocharged applications or vehicles that call for higher octane fuel with E85.
https://www.dragzine.com/tech-...gs-you-need-to-know/

I have a naturally aspirated Fusion with the 3L, rated for normal 87 octane gasoline but rated for an additional 20hp with E85. You'll likely see bigger gains in higher compression or forced induction engines, but it'll still likely gain at least some power for ordinary engines rated to use.

Of course, fuel mileage is awful on E85, so the break even point for my Fusion was the E85 needed to be at least $1/gallon cheaper than 87 octane based on the one trial I did over the course of a few tanks of E85. I have never found E85 priced appropriately enough to justify.

quote:

Originally posted by the_sandman_454:
I have a naturally aspirated Fusion with the 3L, rated for normal 87 octane gasoline but rated for an additional 20hp with E85. You'll likely see bigger gains in higher compression or forced induction engines, but it'll still likely gain at least some power for ordinary engines rated to use.

Of course, fuel mileage is awful on E85, so the break even point for my Fusion was the E85 needed to be at least $1/gallon cheaper than 87 octane based on the one trial I did over the course of a few tanks of E85. I have never found E85 priced appropriately enough to justify.

Yeah, I did a little more reading and there are a small amount of NA cars that will see a small HP gain but it won’t offset the MPG loss. Some normally aspirated cars/trucks can see as much as a 23-24% loss in fuel mileage with E85. The only way I would run that in my truck would be if it was a lot less expensive than gasoline than it currently is, like you said.

quote:

Originally posted by dynorat:
Advantage is you get a 'hardened' fuel system built to resist the corrosive effects of alcohol, and the option to run moisture absorbing E85 that sat in the hot sun for who knows how long if you have no other choice.

This is why I choose a Flexfuel vehicle if possible. The fuel system is much less susceptible to corrosion. My 2003 Explorer with the 4.0 V6 was Flexfuel and it got 15mpg on 87 E10, 10mpg on E85, and 18mpg on ethanol free 90.
I noticed no power difference with E85 or 90 ethanol free. E85 not 90 ethanol free were not cheap enough to make it worth while.


Last I shopped for new vehicles Flexfuel was not an upcharge but it has been awhile. My guess is Ethanol is so heavily subsidized the manufacturers get a kick back for making them but don’t charge the customer as likely very few people would buy them if they cost more.

On the used market a Flexfuel vehicle does not command more either.

If you buy a flex fuel vehicle it does not hurt to see what your mpg numbers are but doubt very little it will be enough to save you anything especially with as cheap as gas is currently.

A good rule of thumb. The more alcohol a fuel has the less mileage you get.

Anecdotal sample of 1.

When I was working for a Chevrolet dealer in college, we had a guy bring his FlexFuel Silverado in.
He'd filled up with E85 & was not happy with the 9mpg it resulted in.

I don't recall the actual reason he'd brought his truck in, just that that was mentioned while it was in the shop.

In my car if you want to squeeze the most HP out of it by tuning it you run E30 or E40 by mixing 93 and E85. With the proper tune and the ethanol mix you can get an extra 80 or more HP out of it. It's like running higher octane gas. You can shove more air in your engine, advance timing, and have more combustible product in the cylinder. The downside is you burn more product as well, but I don't really care if my car gets 16mpg vs 17mpg.

As far as the original question, it's a more expensive and more robust fuel system. You can still use regular gas in it. If buying new you are paying for that, used it probably adds very little to the price if anything.

quote:

Originally posted by Largefarva:
I don’t know all the details but what you said makes sense....where I first heard about E85 was on some F150 forums when I had a 2011 with the ecoboost engine. It became a hot topic for a bit when some guys were seeing if there was a way to run E85 in their ecoboosts. So that’s where I first heard about it. But even in the article you posted it says that naturally aspirated engines can benefit from E85 because of the cooling effect which creates more power....it just wouldn’t be as much as with a turbo or super charged engine. Or am I reading it incorrectly?

Both are kind of correct. E85 does have considerable less energy than regular gasoline, so for an engine set up for regular gasoline you are going to get less power and see lower fuel mileage.

E85 has much higher octane however, so you can run higher compression and more timing advance without detonation if your engine/ ecu software are set up to handle it. Both of those will allow you to efficiently burn considerably more fuel per compression cycle, making much more power.

Flex fuel is good IMO for a few reasons. First, more power. The engine should run more advanced timing with more Ethanol. Higher ethanol content actually runs cooler than straight gas. Lastly, running E85 through your fuel system has great cleaning properties.

I had a Cadillac CTS-V that was setup for flex fuel. I could get over 100 more HP timing for E85. Of course your mileage also goes down with E85.