Originally posted by eepals: I agree with Big Jim on conventional oil. The cost alone, plus changing @ 3000 miles, the oil never gets close to the black color(I know the oil is doing its job, hense it gets dark, keeping the engine clean) that the synthetic oil would be at ,say 5,000 miles, keeps the engine cleaner. On my sisters BMW, a 2000 model, normal oil change interval is 15,000 miles. At 15,000 the oil is "BLACK" and feels thicker than the 5-30 it started its life at. I have since started to change it @ 7,500 miles, since she is planning to hold on to the car. Another reason I wouldn't want to buy a car off a lease.
You can not tell the oil condition by looking at the color of oil. Oil is supposed to turn darker and darker when subjected to repeated heating. When I ran Mobil 1 in the old engine, I change it at the shortest 5k mi or 5 months. I'm running dino oil in my new engine for break-in right now. But as soon as I hit the next oil change, I'm going back to my Mobil 1 routine with 5k mi or 5 months oil change. Only thing I'm going to change is to use Motorcraft oil filter instead of using K&N oil filter.
