I still Confuse to know what different characteristic in using lubricant for diesel and gas engine. Is there possibel if we use the lubricant for both of engine?

Jeff

Yes there are products that can be used for both diesel and gasoline engines. Its called a "Mixed Fleet Oil". API specifications prefixed by a "C" denote compression ignition, diesel. And Api specs prefixed by an "S" denote spark ignition, gasoline. Therefore as an example, Texaco Ursa Premium TDX SAE 15w40 with the API specs of,
API Service Categories
— CI-4, CH-4, CG-4, CF-4, CF, CD1
— SL, SJ, SH, SG
Is compatible with both diesel and gasoline powered equipment. Please verify thatm the SAE grades applicable for both engine types however.
There are many "Mixed Fleet Products" out there, just verify the API specifications.

Hi Jeffturbo,

Do you mean gas as in LPG or CNG fuelled engines? It depends - for passenger cars, most oil companies have a multigrade engine oil that would suit petrol, diesel and gas. You need to check which ones they are by contacting the oil supplier. Many of these oils still carry both the API C and API S specifications.
For gas fuelled commercial vehicles such as trucks and buses, there are engine oils on the market specifically designed for them. These gas engine oils are still a multigrade such as 15W/40 but tend to have lower TBN (eg TBN of 7 to 8)and lower ash (eg 0.8% ash) so the use of ashless type dispersants are quite likely. They are designed to protect against deposit formation particularly in the piston crown area which could lead to uncontrolled ignition and loss of engine performance.
Other gas engines are termed stationary engines - designed to provide power and heat generation particularly at remote locations such as mine sites. These run on a variety of fuels including natural (liquified and compressed) and landfill/swamp gas. As they operate at remote locations and run 24/7, so they run for extended periods of time and under severe stress. Most GEO (gas engine oils) desgined for such application need to provide good oixdation and nitration resistance, deposit control to avoid knocking in the combustion bowl and corrosion control especially where corrosive landfill gas is used. Such GEO tend to be monograde eg monograde 40 with low ash depending on manufacturer (typically around the 0.4%). They tend to be made on salicylate chemistry which has proven to give very good deposit, oxidation and corrosion. Most oil suppliers will have an oil to suit depending on engine type and gas used.

I mean gas engine for using in power plant like diesel generating set.Usually it use methane gas or land fil natural gas

Ok then, ReneWA nailed it on the head. You need to provide your lubricant supplier with the proper info on your type of gas and engines.