BMW e36 325i Ethanol

Trev24

Member
Good day all,

I have an e36 325i, the car is tuned but is not tuned on high octane fuel, so aside from the branch exhaust and chip, the car is standard. So I'd like to know, is it possible for me to run ethanol? Not a 50 50 mix, but like 5 litres or 10 litres to every 30 litres unleaded petrol? Or is this going to damage the engine?
I am aware that the ethanol won't make a big difference since the car is not tuned for it but I'm sure the little boost will help.

Any advice is really appreciated.

Thanks:praise:
 

Hubblyking

Honorary ///Member
To be honest with you i converted to full eth on a e36 m3 3.2 motor with no gains and that was with bigger injectors and upgraded fuel pump.The fun started happening after the compression was raised to.13.5.the gains was about 17 whp.
 

TurboLlew

Honorary ///Member
You will have no gain unless you tune for it. Depending on the mix you end up requiring a lot more fuel. Running E50 in my 2.0L Subaru, I needed 1000cc injectors to avoid running out of capacity. Need to make sure your fuel system is safe for alcohol as well... not sure about a 325i. The burn characteristics of eth are different to normal fuel... People think it boosts octane. It doesn't... it has the same knock supression characteristics as a high octane fuel but needs totally different injector duty cycles and ignition timing to get it working properly. Ethanol has less energy per gram than regular fuel hence you need to flow a lot more.

High compression and turbo motors benefit most as do vehicles with highly adaptive ECUs. Newer cars are able to adapt quickly which is why it can be widely used these days on VWs and BMWs. On eg: a Subaru, chucking in Ethanol of any concentration and hoping for the best as you would with Torco or NF will simply not work. You need a separate ethanol map. I suspect the same would be true of older BMWs. Chances are very low that they will adapt or respond positively IMHO but maybe someone with specific experience on these cars and ECUs can respond.
 

Bazza

Active member
Great thing about ethanol is that the motor will never knock. It's make it live pretty much forever, but your fuel range will go down and bill per liter up.
 
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