BMW state that e10 fuel is quite safe to be used in our M3s.
Their was a big info campaign ran here in the UK a few years ago on the news when e10 replaced e5 for regular petrol.
Over this way at least, in general, most cars after the early 2000s are ok with e10 (e.g my mothers 2003 Suzuki Wagon R is fine with e10 according to Suzuki).
But, I thought the problem with
later cars and ethanol is not the ethanol itself, but that it is more hygroscopic, and it's the greater amount of water absorbed in the fuel coming out in some conditions? (Perhaps sitting around for a long time?).
Bimmerrob
Did you mean 23 months? or 2-3 months, 23 is a long time!
