Can I Use 10W 40 In My Honda Riding Mower?
Can I Use 10W 40 In My Honda Riding Mower? It is okay to put a quart of 10W-40 in an engine with 5W30 in it. The oil will be lower viscosity, but should be fine, if it is a quart of 5W-30. The other way around is to change it from 5W-30 to 10W-40.