Diesel oils-they're changing

Wow
Walmart's super tech heavy duty has even more zinc than Rotella T4
Thanks for the link Ken

Since for years now diesel 15w40 oils have had plenty of zinc in them and they work good in our older flat tappet engines I figured I'd mention what is happening to zinc levels with the latest classification of CK-4 for diesel oils.

Previous 15w40 diesel oils were classified as CJ-4 and they do have plenty of zinc, around 1100 to 1500 ppm depending on the brand.

Just coming on the market recently are the 15w40 diesel oils with a CK-4 classification and these oils are much lower in zinc,like in the 800 ppm range which most people would say "ain't so good" for the older stuff. Saw some the other day on the shelves.

So, if you're looking at diesel oil for your older flat tappet engine look at the classifications printed on the bottle and if CK-4 is there it's probably low on zinc.

There are still some that have 1200 ppm or so in the new rating but the PQIA has only tested a few of the CK rated oils .

You can read tests of 4 brands on the PQIA website along with info on the newer classification You notice good ole'Shell Rotella still has about 1200 ppm even in the CK-4 classification. at least for now   

PQIA