Engine oils meeting the GM dexos I / dexos1™ specification are now required as the factory fill for nearly all EU and US petrol powered cars from the General Motors group (Vauxhall, Opel etc). The exceptions will either require dexos2™ or other specifications (refer to your owners manual for details). dexos 1 engine oils are classed as fuel-economy oils and supercede GM LL-A-025, GM 6094M and GM 4718M.