Jtax05

Just curious on opinions and experience with people running e85 tunes. Specifically in 991.2 3.0 models. Are you using pump e85 or e85r. What’s reliability over long term for people that’s ran it? Also around my area the e85 varies some in octane rating based on season. Any advice would be good. Currently just running a 93 octane tune. Thanks

asellus

"e85" is more like "e60 or higher" and the e85 tunes out there accommodate this.

many people run e85 and have been for a while without issue.

personally, the nightmare hellscape of running e85 on a daily is absolutely not worth it to me.

no flex sensor and trim map, so you're either on e10 or e60+.
no in-car map switching so you can't just flip over to a 91/93AKI tune easily when you're refueling and can't find e85.
no at-home flashing (at least, with APR), so you can't even do the involved procedure of reflashing to an e10 map without involving an APR shop.

polobai

I have thought about it but scared of letting my car sit with e85 in the tank. My car has sat for 4+ weeks at a time between projects so I am a bit troubled with the thought of e85 in the tank for that long. I have a Cobb v3 so I can switch between maps easily but am waiting for a flex fuel solution. Companies like advance fuel dynamics are making great strides in this area and I hope they can come up with a solution for our motors.

Jtax05

Thanks for input, those were all my concerns. I do travel for work also only way it sees drive time if wife takes it out. I think I’ll hold off and keep 93 tune for now.

Tier1Terrier

@Jtax05 Not to derail the topic but curious what tune you're running and how you like it.

Jtax05

Running softronics, wouldn’t change for anything. Power delivery is solid and smooth. And the knowledge gained from them is bar none in my eyes. No bs on explaining items and performance with upgrades you do. I feel as if some tuner brands try to pinch you for file changes or more money on mods that don’t affect tune at all. Just my two cents.

911dude41

E85 headache. Juice is not worth the squeeze most of the time. I like E85, I get E85 performance uses but nowadays is synonymous with egotistical boy racers looking for every advantage to get bragging rights.

How many guys end up having their night turn short and have to turn back home due to E85 on cruises? All of them unless they get lucky and find a station that matches their correct ethanol content... Most places around town are now E15-E54. One unicorn station still has E85 around here. Now 100 octane has become easier to find.

Jtax05

Yeah that’s how I feel, just not consistent. I would have most likely bought in barrels but then that’s another pain. As I have enough race fuel in my shop for motocross bikes. Shelf life isn’t longest either

AlexZTuned

According to the US Department of Energy the exact ratio of fuel ethanol to hydrocarbon may vary according to ASTM 5798 that specifies the allowable ethanol content in E85 as ranging from 51% to 83%.

Generally, you’ll see anywhere from 60-85% based on my experience in the past on other platforms.

Also, E85 makes more power than 104 and it’s 10x cheaper (exaggerating a bit... but you get the point). The thing is regardless of how you switch your tune - via at home solution or at an authorized dealer (APR), if you switch to a higher octane fuel (race gas or E85) you will need to let you gas tank run empty and go through a procedure to clear out any old pump gas from the DI fuel lines.

You will never be able to switch on the fly to higher octane without draining lower octane fuel first. Simple as that. Unless someone develops a real flex fuel tune, it’s just not in the cards for this platform.