E85

[Tury14]

Hey guys, recently installled the PRL flex fuel kit with the TSP stage 2 flex fuel tune. I know on the website it says to run e35 or e40 but I was wondering if I can run straight E85 in alternative to 91 for everyday driving or would I run into issues? Reason is I don’t want to pay $5 a gallon compared to $3

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[gtman]

Warning: Don't run straight E85!!!!

Thank you.

 

[hobby-man]

No. The fuel system can't handle full E85. E30-E40 is recommended for a reason. Much past that, the injectors can't keep up.

 

[Chaucer]

No offenseto OP intended (you actually asking first shows you’ve got a brain), but I feel like this is why ethanol gets a bad rap. A lot of other folks don’t want to put the effort into running it correctly.

 

[bbeem]

For reference I've run a tank e50 and e60 to test mileage on road trips and afr and fuel trims stay spot on. I definitely didn't get deep into the throttle in fear of taxing the pump and injectors. It gets very similar mileage at 70mph cruise on e60 but I tried to keep it at 20% dbw to not over work it. In fact it got better mileage because I resisted the urge to WOT like sometimes happens on trips.

 

[jason510]

Hey guys, recently installled the PRL flex fuel kit with the TSP stage 2 flex fuel tune. I know on the website it says to run e35 or e40 but I was wondering if I can run straight E85 in alternative to 91 for everyday driving or would I run into issues? Reason is I don’t want to pay $5 a gallon compared to $3

Where are you seeing $5/gallon in Cali?

 

[TypeSiR]

Where are you seeing $5/gallon in Cali?

It’s around 5 now near Santa Monica. He’s tuned so I assume it’s for premium.

 

[bbeem]

I experimented with full e85 blend last week as I had to drive 190 miles 4 days in a row, about 760 miles. I live in Iowa, the corn capitol, specifically Cedar Rapids which is the #1 corn processing city in the world! E85 as low as 1.99 with 91 premium at 3.69 and those other grades around 2.89. e85 has a huge price advantage here and is at almost every station.

I find e85 is usually e70. I usually don't let the 12 gal tank go below 1 gal, usually fill up when 2 gal left- or put 10 gal in. Usually I do 6 gal e85 4 gal 91 to get a 35-40% blend. Last week I filled up three tanks in a row only e85. The reading kept coming to about 68%.

The 4 trips were the same 3.3 hour highway drive. About 70 mph the whole time, never above 40% tps.cmd (barely on the throttle) never above 4000 rpm using only map 1 tune. I was trying to figure how much more fuel was being used. According to the 26mpg on e68 to 36mpg on e35 its using about 28% more fuel. There's definitely not 28% head room on the hpfp or injectors so running e85 full tilt would be disastrous.

Ltft always 0, stft always single digits and usually 0, AFR 14.7 everything was great. I wanted to see how much E68 leaned it out so unplugged the ffc at idle real quick. The stft went up to 12 so I connected it back before ltft raised.

E85 was 54% the price and achieves 72% the milage so over the 760 miles I spent $58 vs $72 on gas, about 20% savings in Iowa. The downside is running more fuel and more corrosive blow by so more frequent oil changes. And the biggest problem, if you drop the hammer you run the major risk of being lean and pop.