Thread: Testing E85. Do you?

Just curious if anyone else test their E85? I'm not sure if they change the blends out here for winter or summer, but currently we're running about 88%

I don't, but I really need too. It seems to vary a ton here.

From a tuning perspective I have only noticed winter blend vs summer blend. Just got a tester a few days ago. Only tried it once but it confirms my suspicions that my usual station does do the e70 blend for winter.

I've been wondering this a lot lately, as I am getting ready to set up my car for e85. Say if it comes out to 75%, would it be recommended to add methanol to a tank to get the mixture right?

No, just tune it for the season your in. Generally, summer blend says around 85-95% and winter blend stays around 75

Originally Posted by ADecker

No, just tune it for the season your in. Generally, summer blend says around 85-95% and winter blend stays around 75

No. Just tune it for right around E80 and never touch it again. Fuel trims handle the rest.

See, this is the reason I spent the $18 on the tester. When I first converted, my trims were acceptable. Around +10 on a stock tune. Then one day, out of the blue, my trims jump up to +16 or more. I suspected fuel, but had no way to prove it. Until now.

88% is extremely high for winter blend. In fact its too high for any stock flex fuel vehicle. That station is trying to maximize their margins by blending less gas in (gas is the expensive part)

But a higher ethanol content is better for a boosted engine, right? Assuming you can tune for it, or it falls within the limits of your LTFT.

In theory yes. But are hard starts and tune inconsistency worth it?

I suppose that would change on person to person basis. If some ethanol is good and more is better, personally, I'll take as much as I can get. Hard starting isn't really an issue here.

As far as a tune is concerned, wouldn't it be "good enough" to just shoot for the middle of the road? Like you showed in your write up. (See, I did read it! )

Shooting for the middle results in maybe 5% trims in either direction when its e70 to e85. I don't like seeing trims beyond that.

Mine came from ebay:

http://www.ebay.com/itm/Quick-Fuel-E...-/311245826828

That was the cheapest I found including shipping.

Brandon, I didn't see our usual winter blend either in Arizona for ethanol. Last year was defiantly down to e70.

I have had a beaker to test out of since I switched to e85. But this year has bee as high as 90% and low as 82

And again this is why I keep saying set the stoich

Originally Posted by 91parkave

And again this is why I keep saying set the stoich

I guess so. I'm going to try to play with the tune a little this weekend. I managed to burn all my mixed fuel out of the tank last Saturday. Literally coasted to the pump. Guess my fuel gauge is about an 1/8th off. Oops.

Anyhow, Pure pump E85 now.

Stoic won't fix blend issues.

But at least it gives your pcm a accurate ballpark target to base fuel calculations from in any circumstance. Just like factory programmed it with 14.7 for gas e85 for 9.87