[JohnE]

Thought I'd share my experience upgrading to E85...

I bought the E85 sensor kit from Skidmark garage in the spring but didn't have the time to install it until recently. The kit wasn't too bad to install. There are a few potential gotcha's though.

I figured the fuel connection part would be the difficult part. It isn't. The fuel line is pretty easy to disconnect. What I did do before disconnecting it was to pull the fuel pump fuse and then run the car until the engine stopped. This depressurized the line. I remember changing the fuel filter on a VW and having fuel piss out everywhere. This avoids that.

The difficult part of the install is in adding the sensor wire to the ECU pin #38 connector. I thought the pin was seated, but it must go into the connector a lot deeper than I thought. The best way to verify if it is seated (it wasn't clear in the instructions) is to pop off the blue plastic mating shield to the connector. When you pop it off, you can see the actual pins and if they are seated correctly. The pin should be flush with the other pins.

If the pin is not seated correctly, the HP Tuners Scanner tool will return a constant value of 40% ethanol.. I trouble shooted everything by verifying voltage to the sensor (12 V) and also voltage from the white wire.. I was reading (0.3V) on the gas I had in the tank. The white wire reads from 0V to 5V. 0.3V is probably 7.5% ethanol or so. I ended up emailed Jeremy from Skid Mark and he helped me narrow it down to the pin not being seated correctly.

Anyway, once I got the white wire seated correctly the sensor finally returned a valid value.

Note. I did pay $499 for the HP Tuners suite. I can do a separate review on this later. As someone who is new to Chevy products, I'm not a fan of HP Tuners credit based model. So I paid $500 to tune 2 vehicles. Kind of a rip off.

But.. on to the good part.

E85 is awesome on this car. The basic tune I used which is a derivative of what I found on this board provides a noticeable increase in power.

Let's face it, the Camaro is somewhat of a gas guzzler. The MPG is good for a V8 engine for sure, but still.. I have averaged 20.5 MPG on premium unleaded. Typically premium unleaded for me has been about $0.70 - $0.90 more per gallon than regular unleaded ($2.85-$3.20).

My first tank of E85 from last week cost me $1.88 per gallon. I expected the E85 to be about 70% as efficient as regular gasoline. So far, I have averaged 17.2 MPG on E85 which would imply an efficiency ratio of 17.2 / 20.5 = 83.9%. I'm going to be conservative and call it 80%. If you use that number, I am paying a gasoline equivalent price of $1.88 / 0.80 = $2.35 per (100+ octane) gallon. Each tankful of gas I am saving anywhere from $10 - $15 per tank plus gaining 25+ hp and torque. So the mod will pay for itself after $750 / $12.5 = 60 fill ups (or roughly 20,600 miles of driving).

Once you do this mod, you will probably want to install the "GasBuddy" app on your phone. This will let you find the lowest priced E85. :-) Today I fueled up at $1.75 per gallon which is $2.18 equivalent! After lighting up the tires, I joked with my son about how we are "Green" now.

-John

[JCunningham]

why do people think this car is a gas guzzler. it gets amazing gas mileage. you have 460hp and it gets up to 27mpg 20 on average. 17mpg on E85 that's phenomenal. thanks for this write up. I hope to be getting my car tuned soon. Just did all the mods in my sig. now if the car reads 40% i know I didnt seat it right. I just put the pin in and tried to some what lightly pull it out. it stayed in place. Thanks

[JohnE]

Originally Posted by JCunningham

why do people think this car is a gas guzzler. it gets amazing gas mileage. you have 460hp and it gets up to 27mpg 20 on average. 17mpg on E85 that's phenomenal. thanks for this write up. I hope to be getting my car tuned soon. Just did all the mods in my sig. now if the car reads 40% i know I didnt seat it right. I just put the pin in and tried to some what lightly pull it out. it stayed in place. Thanks

Feel free to PM me if you have any questions. For me, 20.5MPG wasn't too bad, but I hated the 80 cents extra I was paying for premium unleaded. There would be some gas stations, mainly on the interstate, that were charging more like $1.00 more for premium.

One other thing I noticed on E85. The burble I would get when letting off the gas pedal has gone down now. Probably due to the increase in octane.

I'm fairly new to tuning and am curious about the headers and porting the throttle body. I'm assuming that you would get a power increase with these mods without any additional ecu tuning? The power increase would be due to increased airflow. My car is stock with just the flex fuel sensor and tune.

[JCunningham]

im only expecting another 20hp with the headers, ported tb/im, and cai. so maybe 60hp all together adding E85 from what im reading.

[oldman]

On my daily driver I get 17.5 MPG on E85, I get about 20 on super. It is almost a wash. I should note I get about .6 better mpg with the Michein P4s tires, and way way way better traction.

[JCunningham]

any highway driving on E85? looks like ill have to update the gasbuddy app. there are 4 E85 station with in 40 miles of me but it shows none in my area. I cant find anyway to widen the search. the farthest station for any gas it showed me was 16.5 miles away. the nearest E85 to me is 19.7

[wnta1ss]

Originally Posted by JCunningham

looks like ill have to update the gasbuddy app. there are 4 E85 station with in 40 miles of me but it shows none in my area. I cant find anyway to widen the search. the farthest station for any gas it showed me was 16.5 miles away. the nearest E85 to me is 19.7

Just an FYI, some of the info that comes up on internet searches for E85 is bogus. Went to a supposed E85 station that came from a search, nope, don't have E85.

[RCF]

Originally Posted by JohnE

I expected the E85 to be about 70% as efficient as regular gasoline. So far, I have averaged 17.2 MPG on E85 which would imply an efficiency ratio of 17.2 / 20.5 = 83.9%. I'm going to be conservative and call it 80%.

Just to clarify some info on ethanol vs e85 vs gasoline...

Pure ethanol has about 30% less energy content per gallon than pure gasoline. Gasoline today (99+%) already has 10% ethanol in it. So E85 (if it's truly 85%, most likely it's somewhat less) would have 75% higher ethanol content than gasoline. 75% x 30% = 22.5% lower energy content for E85 vs gasoline.

Have you checked the actual ethanol content? Theoretically E64 would give you approx 84% of gasoline's MPG (what you're seeing). Knowing your actual ethanol content would be nice to see where you are vs theoretical.

[JCunningham]

I believe my torque app will tell me what the sensor is reading. I go to the gas station web site and see if they say they have E85. My tuner told me the Nocos around here test at 90%.

[soloknight6]

Ethanol burns way cleaner than gasoline. I wonder if the reduced soot from running E85 equates to less carbon build up on the valves, less "coking." An issue inherent with the DI engine design.

Id like to see spent oil and vapor from an engine running E85. You have a catch can OP?




Thanks for the insight OP, E85 might be something I do in the future. Being in SD there are a few stations which sell it.

[bigsapper]

@jwdominick - Thanks for that chart! I've got an Apple phone and trying to find an app that allows custom PIDs has been a pain, but the above works with the OBDLink app.

FYI, I just got back from drag week (drove there & back). I was running right at a solid 26mpg on the highway the entire time, with E85.

@soloknight6 - The valve coking comes from oil, not fuel.

[soloknight6]

Originally Posted by bigsapper

@jwdominick - Thanks for that chart! I've got an Apple phone and trying to find an app that allows custom PIDs has been a pain, but the above works with the OBDLink app.

FYI, I just got back from drag week (drove there & back). I was running right at a solid 26mpg on the highway the entire time, with E85.

@soloknight6 - The valve coking comes from oil, not fuel.

But oil is contaminated with soot (carbon black) from the burning of gasoline no? E85 does not produce as much soot.

[RCF]

Originally Posted by JCunningham

I believe my torque app will tell me what the sensor is reading. I go to the gas station web site and see if they say they have E85. My tuner told me the Nocos around here test at 90%.

If I'm not mistaken, official E85 spec is like 51-85% ethanol. Not saying it couldn't be different as stations can blend their own.

[JFM-jr]

I have stations here on Long Island that test at E90