[nioh_lbbm2]

Hi All,

Would running a few gallons of E85 cause any long term issues with the fuel lines or any other components? BMW seems to recommend nothing above E10 and its printed right on the gas cap area.

If my calculation is correct adding about 2 gallons of E85 to regular pump gas that is typically around 10% Ethanol would equate to about 20% ethanol by volume.

[Wattens]

All BMW’s for like the last 20 years or so are ethanol compatible from my understanding.

Give or take a few years or more.

[F87source]

Originally Posted by nioh_lbbm2

Hi All,

Would running a few gallons of E85 cause any long term issues with the fuel lines or any other components? BMW seems to recommend nothing above E10 and its printed right on the gas cap area.

If my calculation is correct adding about 2 gallons of E85 to regular pump gas that is typically around 10% Ethanol would equate to about 20% ethanol by volume.

New BMW's especially the F series are fine because the fuel lines are PTFE lined.

But I recommend when you go above E50 run top cylinder lube https://www.powerpluslubricants.com/...ERTOPLUBE.html
to maintain lubricity as ethanol is an alcohol which does not have any lubricating properties (bad for seals, fuel pumps etc), this way you do not have to run a tank of normal gas in between tanks of E85.


I use this E85 calculator: http://www.georgebelton.com/E85Calculator.php


Also if you do not have a tune yet I recommend ECUTEK or MHD because they either already have flexfuel support or will get flexfuel support and then you do not have to worry about mix ratios, and being off with a tune risking issues. It would be a fill and forget while the car does all the necessary interpolations to make sure the tune is set right.

[F87source]

Originally Posted by Wattens

All BMW’s for like the last 20 years or so are ethanol compatible from my understanding.

Give or take a few years or more.

Definitely not the last 20 years, ethanol additives are relatively recent and fuel systems have not been adapted to handle small amounts of ethanol until recently.

F series and newer you would be ok due to the factory PTFE lined fuel lines, and E series (N54 so '08 and newer) I believe you would be ok too.