Improving fuel efficiency with heavy vehicles
I receive a publication for the heavy trucking industry's fleet operators and the current issue had an article on 121 ways to save money on fuel. Many were applicable to RV users, some are obvious and...
Forum Discussion
pnichols wrote:
I'd like an engineer to explain how high capacity singles can yield improved mileage over duals. ASSUMING that both tire setups wind up with the same overall size rubber footprint on the road surface - how can better mileage result?
I can understand about tracion in the snow: The two slender tires in a dual set will sink deeper into the soft surface to reach solid ground than a single wide tire will sink. Everyone familiar with truck traction knows that fat tires provide more flotation ... but you don't want more flotation where there is a slippery snow surface that you don't want to float on ... you want to sink down through the snow to reach a solid surface to get some bite into.
First, as to mileage, the very stiff sidewall of a truck tire creates a substantial amount of rolling resistance. If you have one tire instead two you have 2 sidewalls not 4, you therefore have a lot less rolling resistance. The other savings is from weight, if you compare 4 standard tires to 2 super singles on aluminum rims the weight reduction is likely 1,000 pounds. That much reduction in spinning, unsprung weight is going help your fuel economy (and ride!) even more.
As for snow conditions, unless you're talking about off-roading, or driving in VERY deep snow on an unplowed road, the penetration of the tire into the snow is based on the ratio of footprint to weight, period. Wider tires have wider grooving to accommodate for the little extra water or snow that gets trapped in the middle instead of blowing out to the sides.
