AUTOMOTIVE GREASE

Automotive Greases typically carry a NLGI (National Lubricating Grease Institute) Consistency Number as well as a Category Description. There are two general groups:

Prefix Letter “L” are chassis greases for lubrication of ball joints, steering pivots, universal joints, and other chassis components.

Prefix Letter “G” are wheel bearing greases.

The recommended testing packages for automotive greases consist of tests for basic physical properties and additional performance tests depending on the grease category or level of severity in use.

NGLI Consistency Numbers:

The National Lubricating Grease Institute has developed a classification system for greases based on the worked penetration number as measured at 25°C according to ASTM D 217. The units are tenths of a millimeter penetration. Grease consistency is somewhat analagous to the kinematic viscosity classification for motor oils.

NLGI

Number

Worked Penetration at 25 C

(tenths of a millimeter)

000

445 to 475

00

400 to 430

0

355 to 385

1

310 to 340

2

265 to 295

3

220 to 250

4

175 to 205

5

130 to 160

6

85 to 115

ASTM D 4950 covers the range from NLGI No. 1 to NLGI No. 3 (220 to 340 tenths of a millimeter.) NLGI No. 2 Consistency greases are the most common for automotive applications but NLGI No. 1 or NLGI No. 3 grades may also be recommended. The requirements of individual vehicle manufacturers should be consulted for these specifications.

Automotive Multipurpose Greases:

Some automotive grease products are offered as multipurpose grease. This implies that the grease should be suitable for both chassis and wheel bearing lubrication.

Such a product should carry a combination of an “L” category and a “G” category rating, as for example, LB-GC, and should conform to the specifications for both categories.

In-Service Tests for Automotive Greases:

A variety of other optional tests have been found to be useful for evaluating in-service automotive greases. These are separately listed.