Just curious ---- A friend of mine owns a 35 ft motorhome with a V 10 triton engine and weights at least 18000 LBS makes 8 miles per gallon. Me with my 55- 331 cid Newport 2- 4 barrel carburetor weighing around 5000 LBS making 8 mpg also ---if I am on a turnpike. I am sure some of you with the 413 and 440 engines with a single 4 barrel carb. are experiencing the same thirsty powerplants. Will new steelbelt tires improve gas mileage, still have the old H 78x 15 4 ply Remington Cushion Air tires. Any thoughts on this . I would appreciate very much.. Sincerely Dieter in Pa 55 Newport