I always thought that livestock ate field corn, oh well..... I have been conducting an ongoing comparison of reg 87 vs 91 octane fuels and FE. It appears that using 89-91 octane fuel (here in MA all fuels must contain ethanol up to 10%). I get better FE, on the order of 5-7mpg better with the higher rating than using 87 reg. I filled up with 89 octane at a bargain Gulf station on my previous tank and noticed that the FE was only as good as when I used 87 octane. They may be labelling it 89 but my thoughts are that they are only selling 87 at the 89 price to make a few more bucks. Just filled up at Citgo with 89 and FE is back up to 50+ mpg vs the 44-45 of previous tank....under similar driving conditions. The 89-91 octane must have more ethanol to boost the rating.??? Or I wonder how they blend it from the underground tanks??? By the way, there is only 1 ethanol E85 station in MA at the present time. So much for all the flex fuel vehicles I see on the roads here. They will all have to fuel up in Chelsea to reap the benefits....