E85 Questions

[Mo-mo]

How much of a worse mpg are we talking? I can usually get about 315 on a full tank of 91. And CPI is the methanol injection correct?

 

[turboAWD]

How much of a worse mpg are we talking? I can usually get about 315 on a full tank of 91. And CPI is the methanol injection correct?

Full E85 is ~33% less energy per gallon, so roughly 33% less mpg (but since mpg isn't linear, it's not exact). Our flex-fuel minivan gets ~25 mpg on 87 (would probably get 23-24 on 91, since 91 has less energy) and gets ~18 on E85. Keep in mind, E85 is also roughly 33% cheaper (sometimes way more), so you're paying less per fillup. Just the hassle of filling up more often.

CPI is like a 7th fuel injector to add fuel to the incoming air in general. I guess it's a bit like methanol in that way, but CPI is usually used with 91 or E85. WMI is the general term used for methanol. CPI and WMI are generally considered "either / or, but not both". Terry from BMS has a FAQ about WMI vs. CPI.

The latest option is an HPFP (high pressure fuel pump) upgrade from BMS that does away with the need for CPI.

 

[AdrianG]

How much of a worse mpg are we talking? I can usually get about 315 on a full tank of 91. And CPI is the methanol injection correct?

Yeah you can probably expect about a 30% reduction in range, but you also get a lot more power (potentially), so that will at least somewhat offset the reduction in range, along with any potential savings at the pump. E85 in Colorado is substantially less expensive than 91, so it is probably worth running as high of an ethanol mix as possible here.

 

[Mo-mo]

Interesting. I'm really interested in the HPFP but I wanna see the numbers. E85 in Nebraska is about 2 bucks a gallon vs 4 bucks at 91. Honestly I don't wanna mess with methanol. I'm also concerned regarding cold start ups. Been as low as -22 or so this winter.

Mind you this is after tax time when I clear up some debt. JB4 is gonna be first, then depending on if I go e85 or not, the pump and then the usual intakes and exhaust.

I appreciate all the input.

 

[AdrianG]

Interesting. I'm really interested in the HPFP but I wanna see the numbers. E85 in Nebraska is about 2 bucks a gallon vs 4 bucks at 91. Honestly I don't wanna mess with methanol. I'm also concerned regarding cold start ups. Been as low as -22 or so this winter.

Mind you this is after tax time when I clear up some debt. JB4 is gonna be first, then depending on if I go e85 or not, the pump and then the usual intakes and exhaust.

I appreciate all the input.

Sounds like fuel prices are about the same between us. I definitely plan on BMS with the other Tuners getting some tunes squared away for full E85. Lozic says he's working on it right now.
My only concern with running high ethanol is potentially damaging something that shouldn't be exposed to high levels of it. People have told me I probably don't need to worry, but I like to know as a relative matter of fact. I know ethanol isn't as much of a concern in newer vehicles as it is with much older vehicles, but I didn't engineer or build these things, I just drive and work on them a bit.

 

[GennyGuy]

Interesting. I'm really interested in the HPFP but I wanna see the numbers. E85 in Nebraska is about 2 bucks a gallon vs 4 bucks at 91. Honestly I don't wanna mess with methanol. I'm also concerned regarding cold start ups. Been as low as -22 or so this winter.

Mind you this is after tax time when I clear up some debt. JB4 is gonna be first, then depending on if I go e85 or not, the pump and then the usual intakes and exhaust.

I appreciate all the input.

One thing to note is distance to E85 stations. I'm not sure if they are plentiful in Nebraska. Maybe so since all the corn, but out east, it's a mission. I've got an hour and 15 minute round trip every time I fill up. It's a pain, but I like the power. I also at the time was not interested in meth. I'm more open to it now, but still not sure if I'll switch. I like just filling up with the pump.

 

[turboAWD]

One thing to note is distance to E85 stations. I'm not sure if they are plentiful in Nebraska. Maybe so since all the corn, but out east, it's a mission. I've got an hour and 15 minute round trip every time I fill up. It's a pain, but I like the power. I also at the time was not interested in meth. I'm more open to it now, but still not sure if I'll switch. I like just filling up with the pump.

Wow. That's crazy. E85 isn't everywhere here in CA, but I've got a pump around the corner, which is why I'm into it..

 

[Mo-mo]

Sounds like fuel prices are about the same between us. I definitely plan on BMS with the other Tuners getting some tunes squared away for full E85. Lozic says he's working on it right now.
My only concern with running high ethanol is potentially damaging something that shouldn't be exposed to high levels of it. People have told me I probably don't need to worry, but I like to know as a relative matter of fact. I know ethanol isn't as much of a concern in newer vehicles as it is with much older vehicles, but I didn't engineer or build these things, I just drive and work on them a bit.

That is one of my conerns as well. Pnp e85 with a tune and a HPFP just seems...too easy. I'm kind of worried about the injectors. But only time will tell

 

[GennyGuy]

Wow. That's crazy. E85 isn't everywhere here in CA, but I've got a pump around the corner, which is why I'm into it..

There's a station 20-25 minutes from my house, mostly highway...........but I'm pretty sure there gas is all water. Had a few people test it and the ethanol content was always super low. Like 50-60.

The other spot that I actually go to is a relaxing drive, all highway and I bring 2 5-gal containers with me so that I don't have to go too often. Also have multiple cars so it's a little less of a pain, but in the summer I'll be in pain, because I'll be highway hunting

 

[AdrianG]

That is one of my conerns as well. Pnp e85 with a tune and a HPFP just seems...too easy. I'm kind of worried about the injectors. But only time will tell

I'm not too worried about the injectors, I think they can handle the work. I'm mostly just worried about certain metals and/or plastics/rubbers being exposed to too high of an ethanol content, but I'm not really sure how much of a concern those items are with newer vehicles.

 

[Thomby]

Full E85 is ~33% less energy per gallon, so roughly 33% less mpg (but since mpg isn't linear, it's not exact).

Yeah you can probably expect about a 30% reduction in range, but you also get a lot more power (potentially), so that will at least somewhat offset the reduction in range, along with any potential savings at the pump.

True for full E85. If you're running E30, or ~25% E85 mixed into 75% 91/93, you should only be down about 8-10% on energy, and therefore mileage.

 

[Mo-mo]

I'm not too worried about the injectors, I think they can handle the work. I'm mostly just worried about certain metals and/or plastics/rubbers being exposed to too high of an ethanol content, but I'm not really sure how much of a concern those items are with newer vehicles.

Fair point. I guess time will tell if it's needed

 

[Mo-mo]

True for full E85. If you're running E30, or ~25% E85 mixed into 75% 91/93, you should only be down about 8-10% on energy, and therefore mileage.

I'm a numbers guy. I'd like to know the actual power differences before pulling the trigger. Waiting on Burger for the results but if you show me a good increase with nothing but a tuner and the HPFP, I'll probably go for it. I just don't wanna lose 33% MPG and spend about 2 large on parts for a 20 whp increase.

 

[Thomby]

I'm a numbers guy. I'd like to know the actual power differences before pulling the trigger. Waiting on Burger for the results but if you show me a good increase with nothing but a tuner and the HPFP, I'll probably go for it. I just don't wanna lose 33% MPG and spend about 2 large on parts for a 20 whp increase.

A new HPFP isn't the most efficient way to power, the reason to do that would be the convenience of running full E85 without any need for mixing, and that's what would cost you the ~30-33% mileage.

Going E30 on map 4 is a noticeable power increase over 93 on map 2, and won't cost you nearly the mileage -- I haven't done a real world calc yet but should be in the 8-10% ballpark by the numbers. Put 4 gallons of E85 per full tank (2 gallons if you're half full, etc), the rest premium, and be done with it.

If you're still stock, your best bet is probably not to jump straight to HPFP but instead give maps 1/2 a try, check logs, then E30 and maps 3/4, check logs, then see how you like those power levels before deciding on CPI, WMI, or HPFP. That's a well-traveled path with proven results.

 

[GennyGuy]

I'm not too worried about the injectors, I think they can handle the work. I'm mostly just worried about certain metals and/or plastics/rubbers being exposed to too high of an ethanol content, but I'm not really sure how much of a concern those items are with newer vehicles.

It's always a concern, but definitely less so nowadays. I am probably off on my numbers, but I believe @Avant put 40K miles on his last G70 and it was full E85 for most if not all of it's life.

 

[Mo-mo]

A new HPFP isn't the most efficient way to power, the reason to do that would be the convenience of running full E85 without any need for mixing, and that's what would cost you the ~30-33% mileage.

Going E30 on map 4 is a noticeable power increase over 93 on map 2, and won't cost you nearly the mileage -- I haven't done a real world calc yet but should be in the 8-10% ballpark by the numbers. Put 4 gallons of E85 per full tank (2 gallons if you're half full, etc), the rest premium, and be done with it.

If you're still stock, your best bet is probably not to jump straight to HPFP but instead give maps 1/2 a try, check logs, then E30 and maps 3/4, check logs, then see how you like those power levels before deciding on CPI, WMI, or HPFP. That's a well-traveled path with proven results.

True, honestly I'm waaaaaaay too lazy to mix fuel at the pumps. I can get 91, E85 and sometimes E40 at some pumps. Even with map 2 should be a decent result. After taxes clear I'm getting my jb4 with all the fixings. After that I can decide on other things before E85. Like Midpipes/primaries and that really pretty CAI

 

[cncBilly]

True, honestly I'm waaaaaaay too lazy to mix fuel at the pumps. I can get 91, E85 and sometimes E40 at some pumps. Even with map 2 should be a decent result. After taxes clear I'm getting my jb4 with all the fixings. After that I can decide on other things before E85. Like Midpipes/primaries and that really pretty CAI

If you don’t want to mix you could upgrade the hpfp or go cpi and do straight E40. I have one out of the way independent that sells E85. Fortunately it’s close to my sisters house so when the weather is nice and I’m out her way I do a blend of 2/3-1/3 93 to E and do a little joy riding for a few days on map 3-4.

 

[rpoffen]

If you don’t want to mix you could upgrade the hpfp or go cpi and do straight E40. I have one out of the way independent that sells E85. Fortunately it’s close to my sisters house so when the weather is nice and I’m out her way I do a blend of 2/3-1/3 93 to E and do a little joy riding for a few days on map 3-4.

Nice thing about CPI is that it might help with valve deposits since now there is fuel in the mixture going into the engine.

 

[cncBilly]

Correct. But if you go over E30 ish it won’t keep up.

Correct. If I had closer access to E85 I would do the flex kit for more leeway on the mix.

 

[Navaids]

It's always a concern, but definitely less so nowadays. I am probably off on my numbers, but I believe @Avant put 40K miles on his last G70 and it was full E85 for most if not all of it's life.

Are you saying he just filled his empty tank with e85? If so, what other mods did he do to it? I’m just starting to read about e85 in cars not flex fuel certified, so please go easy on me. Thanks!