I worked at a grease n go no wait oil change place while in college, and at that time Quaker state had a free 250,000 mile warrenty for any new car. Had to have less than 10k (if I rember right), and had to keep reciepts for every oil change from a Quaker State dealer, and do them every 3k miles. And you could not use any additives to the oil or it voided the warrenty. Until Quaker State bought out Slick-50. Then they wanted us to push that to everyone, even our mothers to drink! Not really, but it was the greatest thing once they bought it, now that is a product that was claiming to make the oil slipperier, thus less friction, thus longer engine life. My thing was if they were offering a 250k warrenty for using their oil, why would using slick 50 benifit you? Like I said I used the restore, and it did make the old puke green renault a little more responsive, but never had any proof, so could have been in my head? Also as it was described to me is synthetic oil has all its molocules the same size, where as conventional oil has large, and small molocules, the small ones blow by the rings, and the large ones eventually get broke down to smaller than small ones and blow by more. Wasn't persay much if any slipperier, just less likely to be broke down as fast. But run synthetic in an old high milage car that has never run synthetic, and will leak out of every gasket in the motor. When Pensoil bought Quaker State in the late 1990's they said it would be common for our Quaker state customers who switch to Pensoil to experiance a lot of smoking, and oil consumption for a period of time, perhaps the whole 3k miles of the oil change
