[mblaucoupe135]

A new gas station opened up near my house and they sell ethanol free gas. Just curious if this can be used in my m240 and, if so, if there is any advantages to doing so? I checked the owner's manual and it didn't say anything about ethanol free gas. Also, I have the Dinan piggyback tune on my car and would love to turn it up a notch, but that requires at least 93 octane gas which isn't readily available in my state.

[inc235]

ethanol free gas usually gets better milege.
ethanol has higher octane rating vs gasoline, but lower energy content.
It is typical to get up to 10% in normal gas in most states.

[danallxt]

Also a undesireable property of ethanol blends is that they are hygroscopic, meaning they absorb moisture from the air, raising the potential for phase separation during storage if the tank is vented to the atmosphere.

[XC3LLR8]

Ethanol free is great for lawn equipment; helps avoid fuel lines and bulbs from deteriorating.

Up to 30% ethanol in your car is ideal. I run E30 and mix it myself (E85 & 93) based off calculations from the Fuel-It app and percentage of fuel in my tank from the myBMW app. I'd run straight E85 if we could unlock our ECU's and flash an E85 tune.

[XC3LLR8]

I also seem to recall ethanol-free is popular in boats, but not sure why?

[mblaucoupe135]

Thanks for all the replies so far. So it sounds like running ethanol free gas in my car is fine, but won't give me any sort of performance/power advantage. In fact it sounds like I need to add more ethanol to get more performance/power!

[XC3LLR8]

Originally Posted by mblaucoupe135

Thanks for all the replies so far. So it sounds like running ethanol free gas in my car is fine, but won't give me any sort of performance/power advantage. In fact it sounds like I need to add more ethanol to get more performance/power!

There's many benefits of ethanol, including a cooling effect. Although, not sure how much additional cooling one would get from just the 10% E found in most gas?

[TheGeekGuy]

Originally Posted by XC3LLR8

There's many benefits of ethanol, including a cooling effect. Although, not sure how much additional cooling one would get from just the 10% E found in most gas?

• Ethanol adds two to three points of octane to ordinary unleaded gasoline, so it boosts the performance of your engine.
• Because of its high oxygen content, ethanol burns more completely than ordinary unleaded gasoline and reduces harmful tailpipe emissions.
• Ethanol prevents gas line freeze-up. It suspends moisture in your fuel system, so you don't need to add expensive anti-freeze in cold weather.
• Ethanol burns cooler than gasoline, so it prevents engine valve burnout.
• Ethanol keeps fuel injectors clean, which improves the efficiency of your fuel system and reduces deposits that can seriously interfere with engine performance.

[XC3LLR8]

Originally Posted by TheGeekGuy

• Ethanol adds two to three points of octane to ordinary unleaded gasoline, so it boosts the performance of your engine.
• Because of its high oxygen content, ethanol burns more completely than ordinary unleaded gasoline and reduces harmful tailpipe emissions.
• Ethanol prevents gas line freeze-up. It suspends moisture in your fuel system, so you don't need to add expensive anti-freeze in cold weather.
• Ethanol burns cooler than gasoline, so it prevents engine valve burnout.
• Ethanol keeps fuel injectors clean, which improves the efficiency of your fuel system and reduces deposits that can seriously interfere with engine performance.

Keep in mind the octane rating you see at the pump takes the included ethanol into account. So 93 octane may really be 91 before the petroleum company adds the ethanol.

Correct me if I'm wrong.

[marcsg42]

Good boat fuel because boats sit a lot more then cars so it stays fresh longer then fuel with ethanol because that attracts moisture , which on a boat moisture is every where when your on the water lol

[mblaucoupe135]

Originally Posted by XC3LLR8

Ethanol free is great for lawn equipment; helps avoid fuel lines and bulbs from deteriorating.

Up to 30% ethanol in your car is ideal. I run E30 and mix it myself (E85 & 93) based off calculations from the Fuel-It app and percentage of fuel in my tank from the myBMW app. I'd run straight E85 if we could unlock our ECU's and flash an E85 tune.

Sorry this might be a dumb question, but is E85 85% or 15% ethanol?

[XC3LLR8]

Originally Posted by mblaucoupe135

Sorry this might be a dumb question, but is E85 85% or 15% ethanol?

The government defines E85 as 51% to 83% ethanol.

But yes, the # is supposed to be the percentage of ethanol.

[mblaucoupe135]

Originally Posted by XC3LLR8

The government defines E85 as 51% to 83% ethanol.

But yes, the # is supposed to be the percentage of ethanol.

Interesting, thank you for the info.

[BG42]

Is it labeled rec90? I still use rec fuel in my older carb bikes. Honestly when the ol girl has a turbo on her ethanol is your best friend. Allows for more boost more timing obviously dme is still locked so you cant load a proper tune but I wouldn't sweat running ethanol gas in anything 20 years or newer.

[mblaucoupe135]

Originally Posted by BG42

Is it labeled rec90? I still use rec fuel in my older carb bikes. Honestly when the ol girl has a turbo on her ethanol is your best friend. Allows for more boost more timing obviously dme is still locked so you cant load a proper tune but I wouldn't sweat running ethanol gas in anything 20 years or newer.

I don't believe so but I'll have to look again next time I'm there.

[RockCrusher]

Originally Posted by mblaucoupe135

A new gas station opened up near my house and they sell ethanol free gas. Just curious if this can be used in my m240 and, if so, if there is any advantages to doing so? I checked the owner's manual and it didn't say anything about ethanol free gas. Also, I have the Dinan piggyback tune on my car and would love to turn it up a notch, but that requires at least 93 octane gas which isn't readily available in my state.

After I moved from CA to AR (Benton County AR) in August 2020 I have had easy access to a station (several in fact) that sell 91 ethanol free gasoline.

After years of living in CA and fueling my vehicles with 91 E10 I was excited to finally be able to run ethanol free gasoline.

So switched my Hellcat to 91 ethanol free. I noticed no difference in performance. If there was any improvement (or drop) in gas mileage it was below the noise level.

Vehicles since then have fueled my vehicles mostly on ethanol free -- the station is very convenient and fuel prices are competitive with other stations selling 91 E10 -- with an occasional use of 91 E10 either here or on the road away from here -- with the same results as with my Hellcat.

Based on how the engines of my various vehicles run, and the fuel mileage, I can't tell which fuel is in the fuel tank.

As an aside, some years ago in Wyoming on a road trip I had a chance to fuel my Porsche 996 Turbo with 93 octane fuel. I don't recall if it was E10 or ethanol free. The Turbo engine reacted very favorably to 93.

While ethanol does help with the octane rating I'd be very surprised if the refinery would blend up some 91 then add the ethanol which could bump the octane rating higher. So barring something official to the contrary I'd have to operate on the assumption 91 ethanol free fuel has the same octane rating at 91 E10 fuel.

Regarding E10 and the actual ethanol content my info is refineries err on the side of caution and do not put a full 10% ethanol in 91 E10 but keep the percentage down in the 7 to 8% range.

You should not run a gasoline that has a higher ethanol content than the factory owners manual calls for. The digital copy of my 230i owners manual allows for the use of fuels with a maximum ethanol content of 25%. (!) (The owners manual also lists the quality standards the ethanol used in the gasoline must adhere to.) I never tried even E15 in my 230i. 'course, you'll have to go by what your 240i owners manual allows for. Oh, just a quick check of my M2 owners manual finds the ethanol content limit is 10% as in E10.

[Rdurty2]

I would just stick to gas with E

I know this is apples and oranges but when I had my Golf R, modified, I did extensive logging with 93 octane that had up to 10%E and 91 octane with zero E. Performance,timing, etc was always better with the 93.

Now if we are talking lawn mowers then definitely use the no E gas.

[inc235]

Originally Posted by RockCrusher

So switched my Hellcat to 91 ethanol free. I noticed no difference in performance. If there was any improvement (or drop) in gas mileage it was below the noise level.

This probably just means Hellcat was not tuned to utilize extra energy content in the 91 w/o ethanol. More energy has to go somewhere (heat or work) from thermodynamic perspective.

Originally Posted by Rdurty2

I would just stick to gas with E

I know this is apples and oranges but when I had my Golf R, modified, I did extensive logging with 93 octane that had up to 10%E and 91 octane with zero E. Performance,timing, etc was always better with the 93.

Now if we are talking lawn mowers then definitely use the no E gas.

93 octane has higher octane...so yeah 91 octane w/o ethanol is still 91 octane rating...

[XC3LLR8]

Doesn't matter if the 91 or 93 has ethanol, they still end up with their respective octane rating.

91 w/o ethanol is 91.
91 w/10% ethanol is something like 89 or 90 and ends up at 91 when the 10% ethanol is added.

[RockCrusher]

Originally Posted by inc235

This probably just means Hellcat was not tuned to utilize extra energy content in the 91 w/o ethanol. More energy has to go somewhere (heat or work) from thermodynamic perspective.

93 octane has higher octane...so yeah 91 octane w/o ethanol is still 91 octane rating...

No it doesn't mean that at all.

While the energy content of 91 E10 is lower than that of 91 ethanol free the correct air/fuel ratio of ethanol is richer (around ~9:1 vs ~14:1 for straight gasoline) so even with 91 E10 more fuel would be added thus the energy content in the combustion chamber would be close enough to not matter. Fuel mileage should suffer but as I mentioned not enough to detect at least with my usage.

The Hellcat owners manual calls for 91 octane or higher. 91 is the minimum. A snippet from the owners manual: The use of 91 or higher octane “Premium” gasoline is required in these engines.

But in CA and here in AR all I could find was 91 either with or without ethanol.

Never drove the Hellcat out of the area but I have driven several of my vehicles (my M-B cargo van, 230i, MINI S, MINI JCW) away from here and had to fuel up with 91 E10 and not one reacted one way or the other in any way I could detect.

[RockCrusher]

Originally Posted by Rdurty2

I would just stick to gas with E

I know this is apples and oranges but when I had my Golf R, modified, I did extensive logging with 93 octane that had up to 10%E and 91 octane with zero E. Performance,timing, etc was always better with the 93.

Now if we are talking lawn mowers then definitely use the no E gas.

The benefit you observed with 93 E10 vs. 91 E0 was all due to the higher octane. Your mods of the R upped the octane requirements of the engine and with 93 you were able to enjoy the full benefit of your mods.

'course I'm assuming VW didn't call for 93 for the R. With my Porsche cars Porsche called for 93 but allowed 91 was acceptable.

Porsche called for 93 (AKI) but all I had access to in CA was 91 and with E10. But in Wyoming in my Porsche 996 Turbo I found 93 (I don't recall if it was 93 E10 or just plain 93) and fueled up. The Turbo engine clearly was happier with 93. Not surprising as that is the octane the engine was designed to use.