I know in AZ, during the summer months the ethanol content is increased...I thought it was up to 15% per the label on the pumps.
Also know that BMW has been known to test the ethanol content in cars with failed fuel components.
I'm not really interested in the political side of this issue...you read crap like this...
"Studies carried out jointly by auto and petroleum industries have shown that E15 automobile damage can come in the form of poor performance, loss of engine power due to loss of compression, and durability issues, he said. Overall, resulting engine repairs could cost anywhere from $2,000 to $6,000."
Gee, ya think there's an agenda there? Now if they said, engines that sit for extended periods of time with these blends are known to have more issues...
and then in the same article...
“The Energy Department conducted its own rigorous, thorough and peer-reviewed study of the impact of E15 fuel on current, conventional vehicle catalyst systems. The Energy Department study included an inspection of critical engine components, such as valves, and did not uncover unusual wear that would be expected to impact performance,” it said.
“The resulting Energy Department data showed no statistically significant loss of vehicle performance (emissions, fuel economy, and maintenance issues) attributable to the use of E15 fuel compared to straight gasoline.”
Source
I know from personal experience both statements have falsehoods.
My car runs quite a bit stronger on my mix and virtually every dyno I've seen. It also gets worse gas mileage...in this car probably because I won't keep my foot out of it...but I've noticed it in my other cars as well when we are running our "summer blend". Ethanol's energy content is lower, thus requires more fuel. If you have...oh I don't know, let's just say a faulty HPFP design and there is a big debate about the affects of ethanol on fuel delivery systems....hmmmmmm
My point..both sides have an agenda.
I definitely am much more careful about letting fuel sit for long periods of time, you really see the affects of that on small engine carbs in the form of clogged jets and sticking floats. Have yet to see anything disintegrate from an E15 mix though.
You read so much stuff...one guy said the reason there are issues is because the ethanol breaks the debris loose from the insides of the fuel station tanks and then dispenses it in to your vehicle. Really, what's that big filter you usually see inline with the gas pump do? I've dispensed plenty of fuel in two clear motorcycle race cans...never once said...damn, that fuel's got debris in it.
Another said it produces more GHG but then it's offset by the CO2 that feeds the corn plants...blah blah blah...
Yes, I know that it attracts moisture and that is why when your car sits for extended periods it starts a bit rougher and could also promote rust. Our cars have stainless steel lines from the HPFP to the injectors and use swage type fittings (no seals). The regulator and LPFP are crap...do I mind if I have to replace any of them...nope. I also know that alcohol absorbes moisture (think Heet...99% Isopropal alcohol), use it for that purpose all the time. Am I going to introduce oil in to my fuel system...nope.
I think a bigger issue with these cars is people buying them and then running crap fuel in them such as 87 octane because fuel prices went so high. I bought my car used and fought a few issues that I think may have pertained to that. Also know that my car had the newest rev of fuel pump in it and 4 (yes I said 4) of the newest injectors in it so I know they were fighting issues. I picked up where they left off...car runs great now..but I don't put crap fuel in it...however I do put E40 in it.
Pro's:
More power
Cheaper fuel (offset by worse gas mileage)
Cooler combustion temps
Did I mention more power?
Con's:
Have to fill up more often
Gotta put my thinkin cap on to get the mix right
Tire wear
Uncertainties:
Fuel system life span
Affects on carbon build up
I'm not saying you don't have a point about adding oil to your gas doesn't have some merit..dunno
but I am saying I don't think I'd want the potential problems that it could cause.
BTW, I did have that exact conversation with a motorcycle mechanic that used to work for a factory team. He said he had experimented with E85 (poor man's race gas) and had also experimented with adding oil, he said the seals weren't really an issue he ran into, more the instability of the ethanol due to it's sensativity to environmental changes and the fact that non EFI engines couldn't compensate for that and he had to rejet all the time. However they did see an 8HP gain, huge for a 60hp motor. He gave up and went back to race gas despite the expense (it had really shot up in price).