Following issue resolved by seller. 5 Stars for service.Timed this pump while topping up the 245-70-16 tires on my SUV from 31 to 38 lbs. It takes almost 1 minute per pound increase. About the same time topping up 215-70-15 tires on my car. The DC plug gets hot while operating pump, plugged into the rear accessory power outlet rated 20 Amps. Be aware of that and keep an eye on it. It might melt!