Caused quite a commotion at the gas station, took 4.5 gallons of RUG to fill up trencher before returning it to rental place. Trencher is 2,400 lbs, trailer is probably 500. The only ways it was obvious that anything was there was back there was 1) constant rattling of everything involving trailer and trencher, b) going over railroad track it gave a little whip to the back of the car. c) consumption was 450 Wh/ mile