CJ-4 Specification — Protection. Simplicity. Proven Performance.
Frequently Asked Questions
Who developed CJ-4?
API CJ-4 was developed on behalf of the American Petroleum Institute (API) by the Heavy-Duty Engine Oil Classification Panel of ASTM International, one of the world’s largest voluntary standards-development organizations. The panel included representatives of engine manufacturers, oil companies and additive suppliers.
Why is API CJ-4 required?
It is driven by the EPA’s On-Highway 2007 Exhaust Emissions Standards that require major reductions in nitrogen oxide (NOx) and particulate matter (PM) for 2007 model year trucks.
When does CJ-4 go into effect?
The ASTM Heavy-Duty Engine Oil Classification Panel approved the standard in January 2006. API is expected to license CJ-4 products by October 2006. This timing coincides with the legislated introduction of ULSD (ultra low sulfur diesel – 15 ppm maximum) for the on-highway market, as well as the early production of EPA 2007-compliant engine hardware outfitted with exhaust aftertreatment technology.
How does API CJ-4 differ from API CI-4 and CI-4 Plus?
Performance tests for API CJ-4 are a combination of existing CI-4-Plus, CI-4 and CH-4 engine tests using today’s fuel (500 PPM S) as well as new engine tests using ultra low sulfur diesel fuel (ULSD = 15 PPM) that is mandated for on-road use. API CJ-4 represents a major performance upgrade over CI-4 Plus in terms of emissions control system durability as well as additional protection in terms of valve train wear, piston deposit control and soot handling capabilities over the previous categories. It also improves oil consumption characteristics and protection against bearing corrosion. Maximum chemical limits on sulfated ash (SA), Phosphorus (P) and Sulfur (S) for API CJ-4 lubricants have been set to address the emissions system compatibility and durability.
Are CJ-4 oils backward compatible?
Backward compatibility was a CJ-4 design requirement. This criteria was met, and it will be stated in the API user language.
When will the new formulations be on the market?
API is expected to license CJ-4 products by October 2006, and the products will be on the market soon after that.
What are the chemical limits for API CJ-4 and how do they compare to the previous API categories?
CJ-4 lubricants will need to be formulated to be less than 1.0% ash, 0.4% sulfur, and 0.12% phosphorus. These restrictions enable the use of exhaust aftertreatment devices such as diesel particulate filters (DPFs) and diesel oxidation catalysts (DOCs) that can be negatively affected by chemicals found in the lubricating oil. The following table illustrates the differences between CJ-4 and CI-4 typical lubes.
| API CJ-4 Limits | API CI-4 | |
| ASH | 1.0% | 1.2 ~ 1.5% |
| S | 0.4% | No Limit |
| P | 0.12% | 0.14% |
| Volatility | 13% | 15% |
What are the implications of formulating CJ-4 oils with the new chemical restrictions?
Sulfur limit of 0.4% minimizes the possibility to use higher sulfur Group I stocks. Reduction in sulfated ash directly reduces allowable detergent TBN levels that may affect marketing claims and potentially reduced oil drain intervals, assuming all other factors remain the same.
Are there any advantages to buying vehicles before model year 2007?
Even if a company’s budget permits, so-called “prebuying” merely delays the eventual need for CJ-4 oils as older vehicles are replaced.
If a fleet includes both 2007 vehicles and older vehicles, will both CJ-4 and CI-4/CI-4 PLUS oils need to be stocked?
Although fleet operators may choose to stock both oils, the expected backward compatibility of CJ-4 allows its use in older vehicles as well as 2007 vehicles. However, it is recommended that the oil analysis be closely monitored and the appropriate maintenance schedule be maintained based on lubricant quality.
What are the main engine tests for API CJ-4?
| Engine Test | Measured Parameters | Fuel Sulfur Content | Comments | |
| 500PPM | 15PPM | |||
| CAT C-13 | Oil consumption and piston depsoit control, iron piston. | X | New test, with closed crankcase ventiliation | |
| CAT 1P | Oil consumption and piston deposit control, iron piston. | X | Steel piston, depends C13 matrix results | |
| CAT 1N | Oil consumption and piston deposit control, aluminum piston. | X | Al piston (DDC, JD, Nav), depends C13 matrix results | |
| Cummins ISM | HT sludge, soot-related wear, filter plug | X | Replaces M11 EGR | |
| Cummins ISB | Valve train wear | X | New test | |
| Mack T-11 | Soot-related viscosity control | X | Replace T8-e | |
| Mack T-12 | Ring/linear wear, bearing corrosion | X | New test | |
| GMRFWT | Soot-related wear | X | Status quo | |
| Navistar 7.3 L | Aeration | X | Status quo | |
How does Lubrizol foresee the U.S. market transitioning to API CJ-4?
Lubrizol forecasts a fairly slow transition as this category is a function of a new requirement for engines starting from zero on January 1, 2007. Industry experts forecast 2007 Class 8 sales to be app. 220,000 units. This will be a very small percentage of the licensed vehicle market, which may result in an overall slower transition.
How long will it be before CI-4/CI-4 PLUS oils are phased out?
It is currently anticipated that CI-4/CI-4 PLUS products will remain on the market until at least 2010.
What will happen if CI-4/CI-4 PLUS oil is used in an EPA 2007-compliant engine?
Because these oils contain higher levels of sulfated ash, phosphorus and sulfur (SAPS), they may cause increased plugging problems in the diesel particulate filters and reduce their efficiency, possibly resulting in engine damage and voiding the manufacturer’s warranty. It is strongly recommended that the manufacturer’s recommendation to use CJ-4 oils in EPA 2007-compliant engines be followed.
Does CJ-4 apply to off-highway vehicles?
No. The standard applies only to lubricants used in on-highway vehicles beginning with model year 2007.
What can our customers expect by adopting Lubrizol’s API CJ-4 technology?
Protection, Simplicity and Proven Performance
Protection – dialed in soot and wear performance provides needed protection as proven by extensive engine and field testing showing excellent performance in terms of backward compatibility.
Simplicity – by maximizing the flexibility for forward and backward compatibility with linkage to a core DI and single OCP VM.
Proven Performance – since the technology is built upon LZ4998 technology with over a billion miles of field testing of PC-10 technology, as well as global OEM coverage.
