Uh ooh. Now we're talking politics. Shut down the thread! hahha
Just because you're 30 or 40 year old tractor still "runs great" doesn't mean that there no deterioration. I have a 36 year old Wheelhorse C-101 lawn tractor that just won't die. I would never claim we haven't replaced any lines, seals, and gaskets, cause we certainly have. And to be honest I don't see what one has to do with the other when talking Ethanol.
I haven't seen anybody bring up one major variable. WEATHER! Wind, rain, salt, heat, cold, even oxygen causes rubber deterioration over time. Not saying that Ethanol isn't a contributing cause too, I'm no scientist, but we all come from places with different climates, countries(policies), and manufacturers(vehicles, rubbers, and petroleum) so your 30 or 40 year old tractor has nothing to do with this debate. Another thing, just let any vehicle(old or new) sit for 10 years with no gas at all and tell me what your fuel hoses look like, or even better, try to put 45psi of fuel through it. Hahha, made me think of taking a shotgun to a garden hose for irrigation drip.
Anyways, any qualified mechanic will tell you, after 30 years it's time to at least replace fuel and vacuum lines. Now there is no doubt in my mind rubber compounds are much more durable today. Doesn't mean that manufacturers today use them. I think they(especially Asian manufacturers) use the cheapest thing they can get. As long as it lasts the 2 year warranty. That's all they care about.
Now, in my humble opinion(please don't bite my head off I'm allowed to my opinion), I believe Ethanol is bad for our traditional gasoline engines. Just because people say it's one way doesn't mean it is. Just look at asbestos, lead in paint and fuel, and not to mention all these prescription drugs that are tested and years later prove to be extremely harmful.
One of my favorite sayings:
Don't believe anything you hear and only half of what you read