CTyler, lots of "mysteries" in life, aren't there? /forums/images/graemlins/wink.gif When my Dad bought his first service station in '56, we had one regular customer who wanted nothing but Texaco (non-detergent) motor oil in his car, but when we changed the oil, he wanted a pint of Marvel Mystery Oil added in place of one pint of the motor oil. Now, personally, I suspect he was getting about the same result as if he had just used a good detergent motor oil, but he was adamant about that being better for the car (and I sure can't say he was wrong). I do know that his old Ford had a lot of miles on it, but it looked and ran like new.