I haven't looked at the numbers but with some very careful driving both city and highway I am still on the tank of gas I bought over three weeks ago! If I can make it to Friday it will be 4 weeks on one fill. I have to admit i'm being very light footed but that included 2 freeway drives in excess of 50 miles each. I have been going the speed limit (but not racing to get there). I am really sold on this technology it works great!

I had own pretty fast cars before, my latest one was a Jaguar S type R, so you know my right foot is a little heavy. But I had manage to get almost 450 miles from a tank of gas ( mostly city driving). Also I did one trip from DC to NYC, giving a tour thru Manhattan to my kids, and a second one, with 7 passengers, I try to get to NYC, but the traffic to cross the tunnel was horrible, so we turn back, had lunch in Bayonne, NJ, and headed to a Phyllis suburb to drop my sister and her luggage. I drove back to DC. First trip I filled up the tank in Burtonsville MD and refueled back at the same gas station! The second trip I had to stop north of Baltimore, So I filled up even that I had still about a quarter tank of gas left. Pretty amazing! According to the computer I got close to 23 MPG. Right now I am averaging about 19.1 on city driving. Still my relatives , some Prius owners, complaint that my Yukon is not a real hybrid!

I finally had to fill up today, exactly 4 weeks since my last fill. This vehicle really blows me away! I still have my cooper s works car to be sporty with but the Yukon actually gets better mileage than the cooper. I am going to take my first road trip next month and see just how it does. Four days after I got it my wife took it to Calif. but really doesn't pay attention to fuel mileage etc, so this will be my chance to put it through its highway paces. I'm planning on using the cruise for part of the trip then switch it off to see if manual driving is more economical than computer driving.
If GM would educate their dealers (the ones left that is) and demand a hybrid specialist at each dealership I think they might be able to sell a lot more of these to prospective SUV owners.