Well, for my older stuff that I had that ran E10, it was about 1 mpg, sometimes 2 mpg less on E10 than E0. The 74 Pontiac I mentioned, a 79 Ford Bronco got E10 most of the time. as has everything else right on up to today.
Now, lets say that there is a 2 mpg loss using E10. And that one is getting 20 mpg normally. E0 in my area runs about 30-40 cents a gallon more than E10. E10 is currently $2.09 in my area for about 11.6 cents a mile at 18 mpg. E0 is running around @2.44. So about 35 cents higher. At 20 mpg and $2.44, cost per mile is 12.2 cents a mile. So the edge goes to the E10 even though it causes a 2 mpg loss, at least for this discussion.
Run a few tanks of E10 and find out what kind of mpg you get compared to using E0. Then decide if it is worth it based on your local fuel price.
Now, lets say that there is a 2 mpg loss using E10. And that one is getting 20 mpg normally. E0 in my area runs about 30-40 cents a gallon more than E10. E10 is currently $2.09 in my area for about 11.6 cents a mile at 18 mpg. E0 is running around @2.44. So about 35 cents higher. At 20 mpg and $2.44, cost per mile is 12.2 cents a mile. So the edge goes to the E10 even though it causes a 2 mpg loss, at least for this discussion.
Run a few tanks of E10 and find out what kind of mpg you get compared to using E0. Then decide if it is worth it based on your local fuel price.