Hi everyone, my first post, so be gentle. I'm working on restoring an old 70's vintage Spanish-built motorcycle(Bultaco) that has a fibreglass fuel tank. I ran across something in my web-surfing/research that claimed that MTBE and ethanol found in some modern gasolines will wreak havoc on the fibreglass gas tanks on these old bikes. Do any of you know whether this is true? How would one determine whether a given brand of gas contains either of these? In my limited experience gas containing ethanol was usually labeled as such at the pump, but MTBE? I've heard of it being nasty getting into ground water and such, but that's about it. I have no idea how commonly or rarely this stuff is used. Is it used pretty much everywhere or only in certain areas? How/where to obtain gas certain to not contain this stuff? I appreciate any info any of you can provide.