Interesting Article.

[Pete M]

Read this today.
It says the LFX is E85 compatible.
Thoughts?

http://gmauthority.com/blog/gm/gm-engines/lfx/

[gringo]

The LFX in the Camaro is capable of running it once you get the E85 sensor and have a tune for it.

[Pete M]

So I guess it's able to run E85 in some vehicles from the factory.
I know they sell the conversion kit and that we need a tune to run it.
Just thought it was an interesting article
Sure would be nice to be able to run it without having to buy the kids or get a tune

[ChibiBlackSheep]

Originally Posted by Pete M

So I guess it's able to run E85 in some vehicles from the factory.

The Impala is flex fuel from the factory

[Pete M]

so I'm wondering if impala parts can be used to convert ours to flex..
would it be cheaper?
would it be necessary to tune it?

[ChibiBlackSheep]

Originally Posted by Pete M

so I'm wondering if impala parts can be used to convert ours to flex..
would it be cheaper?
would it be necessary to tune it?

Wouldn't be cheaper, wouldn't be plug and play.

Yes your car needs to be tuned so that the table that uses the % of ethanol can be used. Will Overkill offers a good way to get it done.

[Gossamer]

i tried E15 in my Camaro for a tank, mileage dropped horribly even though it's supposedly it's higher octane. It wasn't worth the $2.30 I saved because the mileage loss was too great.

I also tried 93 octane and on a tank that was almost purely highway miles, it got about the same as any other full tank rolling down the highway. So the extra $12 for that fill was a waste

So unless your car is really tuned for higher octane fuels or E85 which still drops significantly in MPG due to lower BTU's, these fuels aren't worth much.

Back to good ole 87 for me.

[vs_pete]

Aussie have E10/91/95/98/E85
My ride came with Flex Fuel.
I only run 95/98/E85 which I got tuned.

[ChibiBlackSheep]

Originally Posted by Gossamer

i tried E15 in my Camaro for a tank, mileage dropped horribly even though it's supposedly it's higher octane. It wasn't worth the $2.30 I saved because the mileage loss was too great.

I also tried 93 octane and on a tank that was almost purely highway miles, it got about the same as any other full tank rolling down the highway. So the extra $12 for that fill was a waste

So unless your car is really tuned for higher octane fuels or E85 which still drops significantly in MPG due to lower BTU's, these fuels aren't worth much.

Back to good ole 87 for me.

E15 is effectively higher octane, but does burn faster because it can push more fuel. Just like how 10% ethanol doesn't give you the same MPG as if you found 100% fuel. The effective stoich rate is lower, but your car doesn't adjust for it.

1 tank of 93 won't reset your fuel trims to take advantage of it. You need to run about 3 tanks through before your car would start to relearn and go back to pushing more timing.

[Gossamer]

Originally Posted by ChibiBlackSheep

You need to run about 3 tanks through before your car would start to relearn and go back to pushing more timing.

My 08 impala is flex fuel and I've tracked virtually every fuel tank since I bought it new. Still with 'flex fuel capbility' it still drops off and I ran it for a while when real gas prices got super high.

As for the Camaro, why does it take several tanks to get the fuel trims to adjust?

With modern technology and knock sensors that instantly adjust the timing I would think it would be almost instantaneous?

Anyhow, I've not seen any data anywhere showing improved mileage or horsepower gain showing how high octane is better on a non tuned motor.

I'd love to see some data that shows benefits of higher octane fuels.

I agree, i'm surprised our 11.5 compression motors don't REQUIRE higher octane fuels but before I start putting it in I need to see that it will actually and properly adjust to it.

[Pete M]

I've noticed on highway trios that if I run 93 I get almost 2 more mpg.
Same road, Same 227 milies each way.
I was just curious about the E85 because I've seen the kit and know that Will does the tunes.

[gringo]

Originally Posted by ChibiBlackSheep

E15 is effectively higher octane, but does burn faster because it can push more fuel. Just like how 10% ethanol doesn't give you the same MPG as if you found 100% fuel. The effective stoich rate is lower, but your car doesn't adjust for it.

1 tank of 93 won't reset your fuel trims to take advantage of it. You need to run about 3 tanks through before your car would start to relearn and go back to pushing more timing.

What about the fuse pull or disconnecting the battery for a certain time period? Wouldn't that reset the ECU timing tables?

From my research on here, it seems 95 octane is the magic number where the computer doesn't pull back any timing. Don't know if that's actually true or not.

[ChibiBlackSheep]

Originally Posted by Gossamer

As for the Camaro, why does it take several tanks to get the fuel trims to adjust?

With modern technology and knock sensors that instantly adjust the timing I would think it would be almost instantaneous?

Because these cars are timed very aggressively stock. Which means they knock pretty badly too (stock I was seeing double-digit knock numbers). Once it knocks too much, it pulls timing, then when it still knocks it drops to the low octane table. Then it adjusts from there to get the knock down. Just because it's not knocking, doesn't mean it then automatically starts to try to get into the higher octane table again. It needs to be driven a while without knock before the car tries to readjust. 1 tank of fuel won't do that, it does take a little while.

I don't have hard dyno data, but my real-time MPG and my HPTuners shows the benefits of running 93 enough for me. I've also had to add more fueling, and remove some timing from the stock high octane table.

Originally Posted by gringo

What about the fuse pull or disconnecting the battery for a certain time period? Wouldn't that reset the ECU timing tables?

From my research on here, it seems 95 octane is the magic number where the computer doesn't pull back any timing. Don't know if that's actually true or not.

The fuse pull for some reason doesn't work on the v6, it holds the data. A battery reset should do the trick if you unplug it for an hour.

[gringo]

Originally Posted by ChibiBlackSheep

The fuse pull for some reason doesn't work on the v6, it holds the data. A battery reset should do the trick if you unplug it for an hour.

Thanks, that's good to know.