The North Raleigh Model Railroad Club has done some tests with full profile and low profile freight car wheels. The benefits of low profile wheels are posted at the
North Raleigh Model Railroad Clubs web sight. Their test results conclude that full profile wheels increase corner drag 20%over low profile wheel sets, meaning that a 40 car train with full profile wheels would be equal to a 50 car train with low profile wheels. For those of us who say 40 cars is more than enough, these test results would also translate into less drag against a locomotive. Less drag would mean less maintenance and extended locomotive life.