Originally Posted by SpeedyK
I'm very interested, but curious why the VOA on the 15w-50 shows low ZDDP. I saw a mention of 1371, wondered why the disparity. Need it for flat-tappet engines, so that number is important. Please clarify...
So far I've noticed is a correspondence between ZDDP and quiet running on my bikes. Mobil1 V-Twin (11/qt) is quietest, has something like 1600 ZDDP, then Valvoline ZR-1 dino (7/qt) is next in quietness with around 1300. I have some Brad Penn to try yet and some of the Syntec for vintage engines, just need to ride more so I can test them all out.
Speedy K - I can tell you that we heard what you are saying about the ZDDP. This is the expensive part to oils....
We also felt it was lacking a bit on the 15W50 so we set a benchmark to Royal Mfg. and they have changed to a different Zinc booster additive package. See the VOA a page back and you will see 1750 on Zinc, however they upgraded the entire additive package so I cant wait for the latest oil to come my way and run VOA/UOA. That information and product will be available for both the 15W50 and 10W40 third week of January.