"for higher mileage engines". We've all seen the commercials but does anyone have any experience with it? Does it make a difference?? Is it worth almost double the cost??? Just something I was wondering about!
I always heard just the opposite: You can go from a Synthetic to a regular petroleum based oil, but you shouldn't switch from a standard oil to a synthetic in older engines. The reasoning was that a synthetic will have and adverse effect on your seals and gaskets that are oil soked - causing leaks and failures.I was told once you put synthetic in a motor; you have to keep runing synthetic in it or it will tear it up. Is that true?