here in california diesel oil is low zinc also (for a few years), if it says "low emission" on the jug then welcome to our world
. i still have a jug and a 1/2 of the old delo for my moms and girlfriends new cars (i use 1qt with the regular oil). i use valvoline VR1 "race oil" in my '47, it has high zinc.
"High zinc/phosphorus provides extreme wear protection, including flat tappet applications"
http://www.valvoline.com/products/co...ng-motor-oil/6