BuffaloBill

I'm averaging between 20 and 21mpg on my 2012 Rubicon 2dr 6spd manual 4.10 and stock tires when commuting to work. These conditions are a mix of small towns and hyw, generally traveling 60mph on the hyw. It's a hardtop. On a recent 400 mile trip on the interstate traveling 70mph, bucking some wind for 1/2 that trip, the average was down to about 18.5. I do think gearing is a factor in what mpg is possible, but maybe not as large a factor as what some keepers feel it is. There's 10K miles on it now. Mpg improved over the 1st 5K or so. When new, I don't think broke 18.5 till I had 1K or so on it. The dash mpg read out is usually a couple tents higher. Than calculated. I ran 32" Blizzaks this past winter and first thought they accounted for a bit better mileage (than the stock terrain tIres), but I now think the miles were just building up and things were loosening up or something, cause the mpg hasn't gone down after putting the stock tires on this spring. I do believe the winter fuel formulation isn't as good for mpg as summer fuel. I run the local premium fuel, not for the octane but because that grade here doesn't have the 10% ethanol. If I run the 10% ethanol 87 octane I see the mpg drop about 1/2 mpg. 10% ethanol has about 3% less heat energy, right. So I believe that equates to the mpg loss.