The Cummins L10G was a the compressed natural gas (CNG) powered version of the L10. It was introduced in 1992 and was the first CNG engine to be certified by the California Air Resources Board. The L10G was offered until 1999.
- L10-300G: 300 hp @ 2100 rpm, 900 lb-ft @ 1300 rpm, 2100 rpm
- L10-280G: 280 hp @ 2100 rpm, 900 lb-ft @ 1300 rpm, 2100 rpm