honest advice on a truck for towing 10000lbs

I grew up with 50s and 60s trucks and there were class 8 (80k gvw) trucks with huge gas v8s... I had one and it got 1.5 mpg. I switched to diesel and got 5.5. The question always was and always will be... How many miles will you tow/haul. I think it would be fair to figure about 8 mpg with a gasser and about 12 with a diesel pulling 10k. Crunch the numbers using fuel prices in your area and see how it works out. Maintenance is a little higher for a diesel but that is usually happily accepted, to have the pulling power. I've always gotten the Diesel engine premium back at sale time and I wouldn't figure that in. Another bit of advice... Beware of SB gasses that have a 26 gal. tank. You'll be filling up every 200 miles BTDT! I went to a diesel P/U when We were doing many long camping trip but we haven't been able to do that for several years now. It's just been weekend trips now but Personally I wouldn't go back to gas til we're totally done with RVing. Once you've had a (good) diesel you won't go back. Craig