Has anyone seen any credible evidence that the oils marketed for "high mileage" engines really offer any advantage? They typically sell for a bit more than the "regular" oil.
Can't say this is credible evidence, but here is my experience. I started running Valvoline High Mileage in a V-6 Dakota with about 80K on the clock. Before the switch I was having to add a quart at 2500 miles on a 5K change interval. It did not stop the oil use, but it would let the truck go 5K between changes without the need to add a quart. I sold the truck with 150K on it and still not having to add between changes.
My 73 /6 Dart has 290K on the engine. I changed the oil as soon as I got the car, so I have no "regular mileage" oil experience in it. I run 10w-40 Valvoline High Mileage year round. It uses a quart per 3K. As long as compression remains good, I plan to leave the engine alone until oil consumption reaches a quart per 1000. Because I'm not driving as much and for shorter distances, this engine is on a 3000 mile per change interval.
