Flex-Fuel = more HP?

[Jim in Tucson]

Are there any Flex-Fuel vehicles that have two HP rating? One for gas and a higher rating for E85?

I have looked at the mfg site for every flex fuel vehicle I could recall, and have only found a single power rating.

This seems so dumb to me. I assume the ECU in a flex fuel vehicle must have two sets of maps - 100% gas and 100% ethonal - and simply extrapolates between the two based on the percentage of ethanol present in the fuel. If so, then why not take advantage of the added power output of the E85?

The only new car I could scare up on the Internet is this Flex-Fuel Saab. I'm not sure if this was actually produced or not.

Any EU folks on this sub-forum? I understand that E85 is way bigger on the mainland than it is here in the colonies. I'd like to hear your stories.

I have been following with great anticipation the new Chevy Cruze, which is supposed to have 1.4L turbo flex-fuel motor. However, I have not read any actual power ratings that state whether power will be the same or enhanced on E85.

[mrfred]

E85 only makes more power than gasoline on forced induction vehicles. For NA cars, E85 is going to be a little softer than gasoline, so unless you can find a OEM flex fuel forced induction car, I doubt you'll find two HP ratings.

[sslevo]

Originally Posted by mrfred

E85 only makes more power than gasoline on forced induction vehicles. For NA cars, E85 is going to be a little softer than gasoline, so unless you can find a OEM flex fuel forced induction car, I doubt you'll find two HP ratings.

Right on, a N/A motor would have to run some crazy compression, like 15:1 to take advantage of E85. But there is no way that motor would still run on pump gas. If anything i would bet the motor would make slightly less power than on regular gas.

[Jim in Tucson]

Originally Posted by mrfred

E85 only makes more power than gasoline on forced induction vehicles. For NA cars, E85 is going to be a little softer than gasoline, so unless you can find a OEM flex fuel forced induction car, I doubt you'll find two HP ratings.

So you're saying that an N/A motor tuned for 91 octane could not make any more power if it was retuned for 105 octane E85? That just does not sound right to me. I realize the difference would be much more dramatic with F/I, but even N/A it should be able to run more timing on higher octane fuel.

Flex Fuel turbo cars is still a very short list: Chevy Cruze, Volvo, Saab, Bentley Continental Supersports. I understand there are some more in the EU that we don't have here on the frontier.

[mrfred]

Originally Posted by Jim in Tucson

So you're saying that an N/A motor tuned for 91 octane could not make any more power if it was retuned for 105 octane E85? That just does not sound right to me. I realize the difference would be much more dramatic with F/I, but even N/A it should be able to run more timing on higher octane fuel.

Flex Fuel turbo cars is still a very short list: Chevy Cruze, Volvo, Saab, Bentley Continental Supersports. I understand there are some more in the EU that we don't have here on the frontier.

The key thing to remember here is that E85 is not race gas. It burns faster, and optimum timing for E85 is not worlds different than the timing that can be acheived on 93 octane fuel under non-forced induction conditions. My own experience with E85 for daily driving is that when I'm driving round off-boost, E85 makes the car softer than when I run pump gas. I've played around with timing and AFR, and nothing helps.

I think if you look at companies that are seriously considering E85 as an alternative fuel (I think that the US automakers just wanted the fuel credit), I think you'll see that they are combining E85 with forced induction (usually turbo) motors.

[skiracer]

i swear remember hearing or reading that the American companies that sell Flex Fuel vehicles also advertised that E85 offers slightly more horsepower. HOwever, i don't remember them mentioning specifics though...

[skiracer]

Oh wait, go to this link and clickk on "specifications"
http://www.gmaltfuel.com/tahoe-e85.html


Chevy Tahoe as example
Horsepower (hp@rpm) 320@5200 (Gas) 395@5600 (Gas)
Horsepower (hp@rpm) 326@5300 (E85) 395@5600 (E85)
Torque (lbs.-ft@rpm) 335@4400 (Gas) 417@4400 (Gas)
Torque (lbs.-ft@rpm) 350@4400 (E85) 417@4400 (E85)

[GST Motorsports]

Koenigsegg CCX-R

The CCXR is an "environmentally-friendly" version of the CCX, powered by a modified twin-supercharged V8 engine from the CCX, converted to use E85 or E100 ethanol fuel as well as standard 98 octane petrol. When run on regular petrol, the CCXR develops 806 bhp (601 kW), but when the car is run on E85 Biofuel, the CCXR develops 1,018 bhp (759 kW).

[oldevodude]

Here is an example of N/A car on e85 granted it is a tuner car

http://nationalhorsepower.com/forum/...&mode=threaded

[oldevodude]

And her is the popular science article on the SAAB 148 to 184hp on e85
nothing to write home about but a gain is a gain

http://www.popsci.com/cars/article/2...oes-it-quicker

[skiracer]

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