Just wondering if anyone here uses 15 or 20w-30 for older ranger(98 or earlier). Mostly for valve and/or timing chain clatter, is it better for older engines?

I forgot the technical name for it, but oil companies are taking out the sulphur in the gasoline engine oils for catalytic converters sake. Comp, crane and a load of others recommend using 15W-40 diesel engine oil now because it still has the chemicals that best protect flat tappets. It's what i've been putting in my fathers truck for a few years now.![]()
yeah there ya go zddp, I just knew sulfur wasn't right, but, oh well. A lot of truck engines before 98 were flat tappets still. Also I do agree with the get it quieter with thicker oil though. even though I have used gear oil in an old 300 with 500K on it that burned a quart every 25 miles....it was real quiet haha
drove it for a year with gear oil in it and sold it running with 550K on it