mustangted

even the worst dino oil can do more than 3k miles

BruceH

OP,

It's your car, do what you want. I'd personally feel better running Motorcraft blend with a Motorcraft filter and changing it every 5k than running an expensive synthetic and changing every 10k.

But that's me. Some people want to go 15k with oil and one filter. Some will change the filter every 5k but run the oil for 15k. In the end the only oil related failures I've seen on our cars are from mechanical problems that can't be blamed on the oil.

I haven't gone longer than 2700 miles on my built motor. I put alot of time, effort, and money into it and am willing to spend the money and invest the time to keep up on the maintainence. Some change oil and filter after every weekend of racing. It's all about what you feel comfortable with. You certainly won't go wrong by following the manufacturers recommended service schedule which is 7500 miles for an s197 with synthetic blend.

When my motor was almost stock (cai, tune, etc.) I still changed at 5k intervals. As long as you don't exceed the mileage in the manual you will be fine.