If I recall correctly road wear is quadratic with respect to weight. Two cars wear the road less than one double weight car. This makes sense when you think abo

If I recall correctly road wear is quadratic with respect to weight. Two cars wear the road less than one double weight car. This makes sense when you think about it. In the two car case the weight is divided over eight wheels. In the one car case it is divided over four wheels. The same logic holds for truck weight of course. No clue on the fuel use to be honest. I can see it being worse for two cars vs one double weight car due to air resistance.