Penzoil is on sale for $2.00 qt. Four quarts make a gallon so motor oil is $8.oo/gallon, or more.. Now,, gas has more additives in it, maybe they are similar... But it still isn't up to $4.oo yet.. But, gas has lots of taxes on it, plus more processing, so that means, to me, that motor oil is vastly overpriced. Granted, there are shipping issues and containers,, so.. shouldn't motor oil still only be around a buck a quart?