CH, CI-4, what does this mean?

[James408]

I picked up some Royal Purple 20w50 that had the CH, CI-4, SJ. I know what the SJ stands and the other are I believe a diesal rating. Can someone please clarify?

 

[TomJones76]

Go to URL www.api.org
Click About Oil and Natural Gas
Click In Your Garage
Click Motor Oil
Click Look for the Products that Carry the API Quality Marks
Scroll Down A Page or Two
Click API Service Category Chart
Or go to URL:
http://api-ep.api.org/filelibrary/API_MotorOilGuide_2004.pdf

Basically, SJ is a late 1990s standard for motor oil.
CI-4 and CH are both standards for diesel engines operated on modern, low-fulfur diesel oil. CH is for diesel engines with EGR valves. CI-4 is not rated for EGR-equipped diesels.
API SM with GF-4 is probably what your modern car should be running.
If you have a diesel things are more complex. Ask specifically on here with your make, model, year and engine type for a good answer on C-ratings for your oil, or ask your dealer.
PS- Sometimes, you ask TWO dealers. Mechanics are usually dumb about oils, and dealers aren't always wiser than average. If your manual disagrees with the dealer about oils, trust the manual.

[ June 27, 2006, 03:33 PM: Message edited by: TomJones76 ]

 

[James408]

I am experimenting with this oil in my Pontiac 400. I figured these were diesel ratings so it must have the added zinc that my cam likes. The quarts of RP I picked up seemed new. It atonished me that it had an SJ rating on it. I mean it has the new bottles and packaging that other RP oils come in.
I bought the RP at a NAPA store while visiting in La Porte, Texas.

 

[Ray H]

It's precisely because of the elevated zinc and phosphorous levels that your recent Royal Purple purchase only carries the older SJ gasoline rating. That'll definitely change when the upcoming CJ-rated diesel oils are released.

 

[427Z06]

http://www.swri.org/4org/d08/DieslTst/API-CL4.pdf

http://www.swri.org/4org/d08/DieslTst/APICJ4Summary.pdf

 

[James408]

Ok guys, I made a mistake. The rating is CF, CF-4, SJ. What does this mean?

 

[James408]

I read the URL posted by Tom Jones and it answered my questions on these ratings. Thanks everyone.