According to Opel, GM-LL-A-025 is for petrol engines GM-LL-B-025 is for diesel engines But does anyone know the exact differences in the test tests of GM-LL-A-025 and GM-LL-B-025? The Opel specifications are nowhere to be found (all ACEA requirements, however, I have in detail). 5W-40 GM-LL-B-025 costs me as a pure oil change just 1/2 of 5W-30 GM-LL-A-025. It is obvious to have this in the petrol engine. Finally, according to ACEA A3 is also approved for petrol engines. Also the viscosity would be right according to the service booklet. An oil change with oil (Shell Helix), oil filter and work would cost me only 42 Euro with GM-LL-B-02. With GM-LL-A-025, however, would be due 87 Euro. In addition, there are also Oele, which meet both specifications (but not in the workshop I commissioned).