[Johnny Mullet]

I have torn down many engines and I can tell which ones are maintained and which ones are not. You should change your oil at at least every 7500 miles and rotate the tires the same time.

I can take two engines and perform the same test, but that does not give you an answer on how this effects the engine in the long run. I am also in the heavy truck industry and seen the companies that have tried this "No oil change" routine and it may save them money at first, but after the miles get up there, the engines start to develop problems.

I use synthetic oil and change my oil and rotate the tires every 5000 miles. I also check all tire pressures, air filter, fluid levels, etc at this point.