Thanks for the replies so far gang. Current ride is a '15 F350 SRW, 6.7,cc,4x4,sb,50 gal T-flow replacement tank, B&W Patriot (just bought). For some reason I thought that was in my sig.....my bad, sorry. Tho I'm a lil over on all 3 trucks weights (axle, truck, combo, not overly really worried about that as I'm sure Ford (along w/ GM & Ram) tested it w/a lot more weight than I'll ever have on it. At the time of purchase (off the lot & had a F250 SD 6.0 Lariat), we had a SOB 5er which was lighter and figured a SRW 350 would be sufficient. Well it was while we had that coach. Come last year we got the BC and the extra weight (and not from me drinking Pepsi). It tows the rig just fine, went to ME and no probs. However, looking at FL this summer and tires are the weak link.
They have a combo of 7300 lbs and I'm over that now by 300 lbs. Spoke to a tire dude whom I've known for 30 years and he knows his stuff on tires and he said I'm fine if over a few hundred. Get up to 1,
000-2000 then another story. He goes onto say that if tires are like 1/2 worn they will run cooler VS new and max speed is 75 mph (18" tires), make sure aired up to 80 psi cold. My concern is not only heat generated by going around, but also ambient temp, heat from blacktop etc. So hence my toying w/ a dually when I've said all along "don't need a truck w/ training wheels". Add to this as well, I just bought an extra set of rims and snow tires for current truck last Nov and don't think they will fit on stud/bolt pattern of a dually.
Looking at Fords web site, w/4.10 gears it will most likely tow anything we have now and or in the future. MPG wise, we lost 1-1.5 going from old 5er to the BC so by sounds of things be about the same, but may have to slow down just a tad to get 9-9.5. FWIW, the bc weighs in fully loaded at 15,980 out of 16000. Man that's a lot of stuff!!! Just asking for opinions as I'll hopefully chat more w/the DW next cple of days.
On edit RE fuel tank. Stock tank on the '15 sb was 29 gallon. Replaced w/ the T-flow 50 gallon. Much nicer!!