Do you test your E85? Is detonation more common with our motors?

[Unas2k5]

Do you guys all test your E 85 I test per fill up to make sure it’s at least 70% ethanol.
I thought that was very important
One of my friends has a supercharged Corvette, making 760 wheel horsepower and he doesn’t test his E85. Is detonation more common on our motors vs GM?

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[Cory S]

I pick up 50-100 gallons at a time since I drive 100 miles to get it. I test at the pump. I’ve been getting it at the same location for 2 years now. Always 77-81%.

 

[Cordero1]

Back when I was boosted I would check the 1 pump from time to time. But after a few times of being consistent, I'd only check it about twice a year. I'm about to be tuned for e85 on my n/a car. I'll do the same again. What I would do though, is take a bucket & dump some in it first, like half the bucket. To make sure what ever might be in there comes out. Due to the pump being e30, e50 & such.

 

[Proshop]

I actually never test mine… that being said I do have the luxury of being part of a Facebook group that locates all the e85 gas stations in FL and since in my area we only have 1 station with it for around 45 miles some one always post a test I’d say weekly of that station.

 

[EFI]

he doesn’t test his E85. Is detonation more common on our motors vs GM?

Depends on what engine and compression ratio he has.

The Gen 3 motors have more knock sensors so they should be alot safer in that regards. But the higher compression does make it a bit more risky.

 

[LOL WUT]

I test every fill for peace of mind.

 

[wazslow]

You have to also remember most of those GM cars are running a flex fuel sensor and can run anything from 93-E85 without changing the tune. I never test mine. I watch the knock sensor/fuel trims for a bit after I fill up.

 

[Bullit69]

Same for the Mustang, the wide band 02s are able to calculate the E85 content.
I run a flex fuel tune and can monitor my E85 content looking at the afr. Quality E85 gives me a range of 8 to 10 on the afr scale.

 

[wazslow]

Same for the Mustang, the wide band 02s are able to calculate the E85 content.
I run a flex fuel tune and can monitor my E85 content looking at the afr. Quality E85 gives me a range of 8 to 10 on the afr scale.

No, it's different. You have inferred readings and are N/A Im guessing. Must tuners will not tune for flex fuel and boost on a Mustang.

The GM cars are using a sensor to read actual ethanol content and can adjust timing and fuelling accordingly.

 

[Andy13186]

Pretty sure you can run the same timing on e55 as e85, youll just be running rich if you run e55 on e85 tune. Im not 100% sure though but I do run the same timing on e55 as e85 but with a different AFR.

 

[Cory S]

Same for the Mustang, the wide band 02s are able to calculate the E85 content.
I run a flex fuel tune and can monitor my E85 content looking at the afr. Quality E85 gives me a range of 8 to 10 on the afr scale.

It doesn’t work that way. The O2 sensors are lambda sensors only. They can not detect alcohol content. The PCM targets commanded lambda and uses O2 feedback to keep it there. Your AFR gauge is just a display of what the PCM is keeping target at.

 

[Cory S]

Pretty sure you can run the same timing on e55 as e85, youll just be running rich if you run e55 on e85 tune. Im not 100% sure though but I do run the same timing on e55 as e85 but with a different AFR.

Technically it would WANT run richer yes, but commanded target still stays the same, and the STFT’s will be adding more fueling to keep target.

 

[EFI]

No, it's different. You have inferred readings and are N/A Im guessing. Must tuners will not tune for flex fuel and boost on a Mustang.

So how are tuners able to offer flex fuel tunes if there's no actual sensor?

Also isn't there an "alcohol learned" parameter that the ECU does and it displays alcohol percent? If there's no sensor, how does it infer?

 

[Dvcrogers]

I only run E85 anymore with my car and I never test it, but I run the Fuel IT sensor with the app on my phone. I love that setup.

 

[ZXMustang]

I actually never test mine… that being said I do have the luxury of being part of a Facebook group that locates all the e85 gas stations in FL and since in my area we only have 1 station with it for around 45 miles some one always post a test I’d say weekly of that station.

Dude what group? Im in FL near Tampa and would love to join that group.

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