I put in a fresh oil change before winter lay-up this past fall and used the Mobil V-Twin 20-50 after previously running the Brad Penn 20-50. I can't seem to find any stats on the ZDDP levels in the Mobil however. Maybe it's low? Not sure. I know this was a good oil to run, but I see that Amsoil Dominator 20-50 is advertising having high levels of ZDDP. Maybe that would be better yet? Any thoughts on the latest and greatest formulas of these two oils? Thanks.

It looks like the Mobile V-Twin still has higher levels of ZDDP. Not sure what the other brands have. Here is a spec sheet from Mobile.
http://www.mobiloil.com/USA-English/...duct_Guide.pdf

Lab analysis I received a month or so ago on MOBIL 1 V-TWIN showed 1529 PPM ZINC and 1507PPM PHOSPHOROUS.

Spectro Heavy Duty Petroleum Motorcycle 1816 PPM ZINC, 1643 PPM PHOSPHORUS

Spectro MOTORGUARD 1699 ZINC and 1427 PHOSPHOROUS.

Ken

I use Valvoline VR1, and been very happy with this.

Here's some good info....http://forums.corvetteforum.com/c3-t...ppet-oils.html