That was the recommended "summer weight" oil here in Tennessee for a lot of older engines, with 20W-20 for use down to zero degrees or so in the winter. For the past several years, I've been using 15W-40 Diesel rated oil in everything we own, cars, trucks, lawn mowers, a gas welder, a couple of generators, a pressure washer, and my 97 Harley EVO engine soft tail. No oil related issues whatsoever with any of them! The price of a 5 gallon pail of the stuff from Tractor supply beats buying it by the quart, too!
Jerry
