Hi all, My guy neighbor (who knows almost everything) and I (who knows all the rest) are discussing (disagreeing) on the best type of oil to put in an old, high mileage spare car that burns oil. He maintains, on the advice of an engineer brother of his, using 10W50 is best. I say SAE 30, but I am just the single chick who lives next door. The car is used as an extra vehicle when needed. We live in the middle Tennessee area and a dinner is riding on the answer. Thoughts? Thanks!
Viscosity is one way to cope with consumption. Using a monograde might work just as well. No viscosity index improvers to shear.
I’ll give it a 50:50.
I don’t think he’ll find a 10w-50. 20w-50 would be more likely a find. A 20w-50 will probably use a 30 grade base stock. To get the 10w rating, the base stock might have to be a 20 weight. That’s in a conventional, mind you. There’s a reason why conventional diesel oil is a 15w-40. That’s the biggest spread they can manage and have it remain a 40 grade in prolonged usage.
However, I can offer an alternative that might reduce the consumption permanently. A truly worn out engine is pretty rare these days. Ring deposits usually cause the ring packs to become stuck. Auto-Rx cleans these up in about 500-750 miles of sensible driving. www.auto-rx.com. It reduced my daughter’s Taurus from a quart per xx hours of operation to a quart in months.
I’d use a multiweight, thickest listed for the car. One made for high-miles cars. Definitely not a single weight.
I would also use the multiweight oil say 20w-50. Skip the single weight oil.
I recently tried 20W-50 in my oil using car. It didn’t help. I’m trying the auto-rx now after trying various other additives that didn’t help.
I would favor the #30 oil because it will leave far fewer deposits when it burns than the 20-50…But once the temperature drops below 30 degrees, you can’t use straight 30…So if you don’t use it much, try 15w-40 and see if that improves things.
Yes, prefer the 50W oil. You are unlikely to find it as a single grade, so use 20W-50 or whatever comes closest. You can use it year 'round, since Tennessee does not qualify as a severe winter climate.
I would put in whatever oil is cheaper–whether it is 10W-50 or 30W. My first car used a lot of oil–1 quart every 250 miles. I bought re-refined oil at 10 cents a quart. The car was a 1947 Pontiac and this was back in 1962. When an engine is worn, I think price is the way to go.