The Environmental Protection Agency's (EPA) stricter emissions requirements for 1998 diesel engines have created demand for a new generation of lubricant standards.
The guidelines are for lowered emissions allowances of oxides of nitrogen (NOx) -- a major contributor to ground-level ozone and smog -- and nonmethane hydrocarbons (NMHC), or soot.
To reduce these byproducts, the temperature of combustion must be lowered. This results in more unburned fuel and more NOx or NMHC being introduced into the engine oil. To help burn the fuel more completely and still reduce emissions, these engines have increased injection pressure, higher cylinder pressure, higher piston-ring zone temperature, and retarded injection timing.
As a result, a number of lubricant companies have come out with new oil formulations to meet the demands of the new engines and are running oils through more severe tests to ensure performance.
Although the new CH-4 standard, as the new oil performance category is known, has not been officially licensed by the American Petroleum Institute, individual oil companies have developed reformulated products that meet the standards. The new oils will carry the CH-4 label beginning in January of next year.
Shell Shell has released Shell Rotella T, a 15W-40 heavy-duty motor oil that has cleared the Mack EO-M specification and the Cummins Engineering Standard 20071 test. The new oil builds on last year's advanced soot control enhancement to work harder to protect the valvetrain, bearings, and critical parts from soot. Not only does it offer improved protection, it's capable of extended drain intervals. It also has improved low-temperature flow properties, speeding cold-weather starts.
Mobil Delvac 1300, Mobil Corp.'s newly reformulated multi-grade 15W-40 heavy-duty motor oil, also meets the new CH-4 standard, the company announced. It has been approved for Mack's EO-M and EO-L Plus, and is approved by Detroit Diesel Corp.
Mobil officials says that in addition to meeting those wear tests, the new formulation provides greater stay-in-grade shear stability, which means the oil retains its viscosity in high temperatures.
76 Lubricants 76 Lubricants Co. has released a new version of its 76 Guardol QLT motor oil that features an enhanced formulation with advanced polymers that produce a thicker oil film and special additives.
The new lubricant exceeds all North American four-stroke diesel engine builder requirements and meets Mack EO-M and Cummins CES 20017 specifications. The company also said it would meet CG-4, CF-4SJ, Volvo VDS, Mack EO-L Plus, and Mack EO-L standards. Guardol QLT has been shown to reduce corrosive wear and offers a high TBN for added detergency.
Dryden Dryden Oil Co. has come out with three reformulated heavy-duty diesel engine oils that exceed the CH-4 standard: Dieselall Plus with APC 15W-40, Dieselall with APC, and Supreme XHD 15W-40. All three take advantage of Dryden's new advanced performance chemistry and improved durability additives.
Toyo Tire Corp. has added new sizes for its M120Z, M124Z, and M111Z rib-type highway radial tires. The all-position, all-steel radials are intended primarily for vans and heavy trucks in regional pickup-and-delivery applications, as well as for buses and RVs.
The 12-ply M120Z is now offered in 8R19.5 and 9R22.5 sizes. The 14-ply M124Z has added 245/75R22.5 and 265/75R22.5 low-profile sizes, which are equivalent to European 235/80R22.5 and 255/80R22.5 sizes. The 18-ply M111Z has added a 315/80R22.5 size for heavy-duty applications.