Ibm not wanting to start a debate on oil, oil weights, zddp, or dinosaur juice vs synthetic. Ibm merely imparting what I discovered today. I use valvoline 20w50 full synthetic racing oil in my cars. it has zddp. it is available from amazon by the case (of 6), for less than my local flaps, and free shipping because its over $25 per case. you do pay sales tax