Lotus Elan and Lotus Elan Plus 2 Forums

Could anyone tell me if ethanol has any affect on alloy fuel tanks? My Elan has an alloy fuel tank fitted a few years ago and I find that I get this grey powdery sediment that sits in the bottom of the carb float chambers and wondered what was causing it. I always use Premium E5 fuel.

William
Aluminium is OK to use with Ethanol for the purpose of a fuel tank.
My reference chart states whilst not "excellent" its "Good" for most conditions regarding Ethanol.
Clive

Do you have a fuel filter?

Yes, I have an inline glass filter. I was wondering whether the paper element types are better?
It has been suggested that the grey sediment is caused by gradual oxidation with the alloy.

A grey residue is most likely Aluminium oxide.
In which case its either from your aluminium fuel tank or possible the carbs. (Carbs are my guess)
I personally would expect a small amount of residue, due to the nature of aluminium naturally wanting to oxidise.
If the system is not used much the oxide layer can build up more than normal if exposed to air. Then the fuel will flush off the excess and it will accumulate somewhere.
Just make sure you don't have any stainless steel fittings in your fuel line otherwise you can make the problem worse as the two metals react with each other
Clive

Hi Clive, thanks for the advice and information. I think it explains what is happening. I also recently replaced all the fuel hoses with Cohline ethanol resistant rubber. I do wonder whether pouring an additive in the fuel tank might help.

Have a chat with the technical guy at Millers Oils, they have been doing quite a bit of work on Ethanol and carb/tank issues, found him really helpful.
Tony

Your filter should stop anything from the tank so it seems likely that the carbs are the problem.

I have been using Castrol Classic Valvemaster Plus on all my classics and my cars seem to run better.