I have a 1979 honda CB750 and the thing definitely doesn't like ethanol. It runs a lot better with straight gasoline like they put out in the late 70's

 

When I use Lucas Ethonal treatment on a full tank I see about 2-3mpg gain. At $20 a bottle and getting maybe 3-4 treatments out of it depending on the size of your tank.

 

It's 3.69 here (ethanol fuel), nonethanol is 3.74 at the station down the road from me.

 

Ethanol actually burns slower. This is why it has a higher octane rating. It however isn't as powerful as straight gasoline. This is why you get lower performance (in a naturally aspirated engine) and MPG.

 

So I got stuck in the snow yesterday coming back from snowboarding. I was half in the ditch. I put it in 4 lo and eventually got out. It says 4 lo is for 40mph or less. Obviousley was kinda of gunning in at the end to finally get out. When I got out it sounded like the jeep was puttering and it was shaking a little bit. I put it back in all time 4 wheel drive and drive back home which WS about an hour drive. Everything seemed fine after the puttering and shaking went away. Does anyone know why it did that?