[fishbone]

Actually the manual IIRC states 87 at the least, it doesn't say you should get 87 exactly. 89 is still not a waste of money since it's cheaper than 87. Premium is the only gas grade that's a waste.

 

[fishbone]

89 has always been cheaper than 87 here in the Midwest. Nebraska, Iowa, the Dakotas, Minnesota and Wisconsin at least. They all use 10% ethanol with 89, whereas 87 has no ethanol. Any gas that is not premium is fine, just let the price be the deciding factor.

 

[fishbone]

Corn is plentiful here in the midwest
Go to lincolngasprices.com and see for yourself, 89 is around 10c cheaper than 87.

 

[fishbone]

Won't really help your engine last longer, I really don't see how that would be. It will burn cleaner than 87 though, since it's cut with ethanol. It also has a tendency to be a solvent, so it'll keep things clean.