case lube

bruce381

Active Member
T4 contains zero zinc as far as I know. It uses Ca Suphonate instead as an EP, corrosion-inhibiting, and overbasing component. It also contains a mega-load of ashless dispersants and antioxidants that aren't really needed in a gas engine except to suspend the sludge created by the shear breakdown of the viscosity modifiers, and is all in a mediocre base oil which is far too viscuous.

There are many reasons why lubricating oil for compression-ignition engines are formulated differently from that intended for spark-ignition engines, and why API, ILSAC, and SAE have specific (and vastly different) specifications for each. Best plan is to use the appropriate type for the application and supplement known deficiencies.

Ian still has 1000-1200 PPM ZDDP is NOT zinc free
 

462

California's Central Coast Amid The Insanity
Hold the mayo on mine, and raspberry or blueberry yogurt, please.

(Talk about getting educated.)
 

Ian

Notorious member
Ian still has 1000-1200 PPM ZDDP is NOT zinc free
Yep, I finally got to the bottom of that this evening. How they hide it in the SDS still baffles me. Still, it's cut way back from CJ-4.

I called the owner of my old shop to see if he needs his fence stretchers back and also asked him if he had sent any stuff to Blackstone recently (I used to do it frequently when I worked there). He said he's been recommending Tractor Supply diesel oil (for diesels) lately because it's cheaper than Rotella, Delo, or Delvac and still hits the CJ level of zddp on the tests. I thought that was interesting. Also, he thinks the reason for 1200 ppm still being the max for CK (depending in how much phosphorus is in the zinc compound) is because Cummins is still running flat tappets, altnough I don't k ow why this matters since Cummins tappets have a polished, tungsten-carbide puck brazed on the bottom, so it's a little different situation from steel tappets rubbing on a cast-iron cam lobe. Being an FCA tech I know that the light truck Cummins coming out next year in the Ram trucks will be full roller so I see that going down even more in the next iteration of diesel crankcase oil.

Anyway, the old trick of putting diesel oil in an old gas engine for the zinc isn't getting you what it once would have but there's still more than twice the zddp of current gasine engine oils. I maintain that a spark ignition oil which is formulated to contend with the unique combustion byproducts of gasoline/ethanol is the best choice for that application, ymmv. Anyone can phone up or email the major oil manufacturers and ask which product they recommend for a specific application, I've done it many times myself.
 

bruce381

Active Member
"How they hide it in the SDS still baffles me"

yep
FYI PCMO ia capped at 800 I think but if the oil is specked for HDEO Diesel first as in CJ-4/SN then you can use 1200 if just SN then 800 or so.
 
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Ian

Notorious member
I am familiar with that marketing trick. Do you have any idea what the limits are for the new FA diesel oils?
 

Mitty38

Shatterpated Constituent
Call me strange but i always follow the owners manual on oil to the t . figure they engineered the thing they should know better then me how to keep it lubed and going. Unless the motor is on its last leg then whatever is on sale in 20w50.
 
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