How does Quaker State compare with Pennzoil? The reason I ask this question is because my dealership uses Quaker State and I can get oil changes there for $19.00. This is so low in cost that I am tempted to get oil changes at the dealership, because it would maintain the warranty on my new car for sure (they could not say I have nelgected the warranty) and because $19.00 is actually cheaper then it would cost for me to do the oil changes myself. The car uses an oil filter element and the lowest price I have been able to find for it has been $7.00. Combine that with the cost of the motor oil (five quarts) and it is hardly worth it to change the oil myself. I know Pennzoil is a good conventional motor oil-perhaps the best there is OTC. But I do not have a clue how Quaker State compares to it. Shell, Pennzoil, and Quaker State are now one company, but apparently their motor oil formulations differ. If the dealership used Pennzoil motor oil, it would be an easy decision (especially since I have found out that Pennzoil conventional apparently flows well in the cold). Does anybody know hoe Quaker State compares?