E85 in a Stock Fuel System
Senior Member
Joined: Jul 2010
Posts: 424
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From: Sac, Ca
‘17 GT F1A E85 Monster ‘16 C63s
I’ve ran up to 2.5 gallons of e85 blended in 91 octane without issue. Yes our fuel system is compatible, however, it doesn’t have the pumps to support the addiotional volume needed when running ethanol and the car wouldn’t be able to run full e85 even with a high pressure fuel pump upgrade (idk if one is even made for this car) as most direct injection cars will use meth injection to help supplement fuel when running a higher e blend.
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Member
Joined: May 2017
Posts: 97
Likes: 10
2017 C63s Edition 1 JB4
I’ve ran up to 2.5 gallons of e85 blended in 91 octane without issue. Yes our fuel system is compatible, however, it doesn’t have the pumps to support the addiotional volume needed when running ethanol and the car wouldn’t be able to run full e85 even with a high pressure fuel pump upgrade (idk if one is even made for this car) as most direct injection cars will use meth injection to help supplement fuel when running a higher e blend.
Senior Member
Joined: Jul 2010
Posts: 424
Likes: 41
From: Sac, Ca
‘17 GT F1A E85 Monster ‘16 C63s
No prob! I didn’t calculate octane, but you could use an online calculator based off actual gallons of each. I know it’s more than enough to keep maximum timing in any stock turbo car tuned or untuned.
Super Member
Joined: Jul 2008
Posts: 583
Likes: 23
From: Colorado
2021 E63 S Sedan
If you want performance improvement, you can put higher octane fuel in the car, but the car has to be tuned to use it. If you get an ECU tune, you can have it tuned to the type of fuel you'll be using. If you put (or blend) higher octane fuel in your stock car, you'll just not see a performance (horsepower) improvement.
Regarding E85, if you put 3 gallons of E85 + 91 octane to fill an empty tank, you'll get about 95 Octane. It's an estimate because E85 has a range of equivalent octane, which varies from distributor to distributor.
Regarding E85, if you put 3 gallons of E85 + 91 octane to fill an empty tank, you'll get about 95 Octane. It's an estimate because E85 has a range of equivalent octane, which varies from distributor to distributor.
