There is currently no universal, harmonized specification for gas engine oils. The large variations in operating conditions between mobile and stationary engines generally require oils with different additive packages. A general difference is made between high-, medium-, and low-ash types which are recommended by the manufacturers in line with the designed use of the engine. As a rule, gas engine oils are subject to high oxidation and nitration which can accelerate the aging of the oil. Gas-powered cars normally use the same conventional engine oils as are used in gasoline-powered engines. Diesel engines usually need oils with a higher TBN (Total Base Number) and with more dispersants than gasoline engine oils. Typical qualities for car engines are API SL and / or ACEA A3 (gasoline engines) as well as API CG-4 and / or ACEA B3 (diesel engines). Similarly to the automotive sector, multigrade oils are used to cope with variable operating conditions and to guarantee reliable lubrications at low ambient temperatures. As the number of CNG-powered cars increases, there is an increasing pressure to develop oils which are especially formulated for these applications.

This could mark the beginning of a future, uniform specification. Special multigrade oils have already been developed for use in heavy diesel engines, with CNG-powered buses being the major application. These have been tested and approved by various engine manufacturers. Examples of these approvals are Mercedes-Benz Sheet 226.9 or MAN M 3271. These oils were tested in bench tests as well as in realistic field trials. Stationary gas engines can make significantly more complex demands on the oil and this has an effect on their development. Oils for stationary gas engines thus require significantly more development work and have to be better matched to the engine and operating conditions than normal automotive engine oils.

The development and application of gas engine oils thus normally takes place in close cooperation between the oil and engine manufacturers who normally issue an approval after successful completion of trials. Gas engine oils were developed for total energy systems operating in high-temperature environments. It also gives maximum protection when the natural gas contains excess sulfur. The oil stands up very well under severe oxidation and nitration in the natural gas engine; alternately fueled vehicles powered by compressed natural gas or liquified natural gas. The formulation is maximized for outstanding deposit control.