I used my $10 Advance Auto coupon on 6 quarts of Castrol Edge 5w30 which came to $30 out of my pocket. The Castrol Syntec was priced at 6.99 and the Edge was 6.59 per quart. I figured this would be the time to try it out since I had the coupon. Anyway, lets hope it was a decent purchase for the Summer heat.