Originally Posted By: FordCapriDriver
so i've found at a local store some chaep mineral 20w50 to put in my car , it's rated API SG , Does this nececsarily mean that it would have more ZDDP than the current SL rated oil i am running?
Originally Posted By: Shannow
OP, have a look at
http://www.aftonchemical.com/ProductDataSheets/Engine Oil/HiTEC-9300C-SERIES_PDS.pdf
Particularly the treat rate charts...
I reckon on balance of probabilities that a "cheap" SG would have less additives than a decent SL, as per Tom's testing.
I agree with Shannow and Tom, any modern cheap SG 20W-50 is more likely to have a low treat rate and probably has less zinc than a regular SN oil (about 800ppm). I think things like A3/B4 Euro oils are more likely to have about 1000ppm Zn, especially things like M1 or Edge 0W-40.
The big issue is that the OP wants a 20W-50 for his 70's Ford Capri. So most of the options we are giving him like M1 0W-40 or a 15W-40 HDEO are too thin for him (if I recall his earlier thread correctly).
I don't know many A3/B4 or CJ-4 oils that are 20W-50.
OP, you have access to Valvoline VR-1, that's the oils for you if you are chasing a high ZDDP 20W-50
Avoid the cheap stuff, because it's most likely cheap because of a low dose rate.