REV XZDDP Oil Additive - Zinc & Phosphorus (2 Pack)

Éste producto es para camiónes o para carros pequeños de 4 clds.?

Zinc additive products... some containres are 2oz and some are up to12oz. Is more better, does volume make a difference?

My 351W in a classic mustang uses 5 quarts, so im assuming I should add only 1.666 ounces?

I have a 2004 Toyota Avalon and a 2002 vw Passat would this work for that in my engine oil?