 From 2005, the "Z20LET" engine was revised for the Astra H and Zafira B, to three different model designations, "Z20LEL", "Z20LER" and "Z20LEH".The differing designations denote the engine power output, , and .Further revisions to the original design include under-piston oil cooling, a revised turbocharger unit and the deletion of the contra-rotating balancer shafts in the "Z20LEH" engine (as used in the Astra VXR), to reduce mechanical losses.