Why cant we use the new Enviro+ oils in place of the existing HPR range?
The Enviro+ range are oils which are low in SAPS (Sulphated Ash, Phosphorus and Sulphur), which in turn is low in zinc (zinc is a part of the same compound as phosphorus, which is a catalyst poison). Zinc is a very effective anti-wear agent and if it is reduced, may cause premature wear in the engine, especially if they use flat tappet cams. However, vehicles which have the diesel/catalysed particulate filters (DPF) in the exhaust need a low SAPS oil to prevent premature blockage of the DPF. Replacement/manual regeneration of the prematurely blocked DPF has been known to be a costly enterprise. So unless the Owners Handbook specifically state an ACEA C1, C2, C3, C4 or API SM and higher, the Enviro+ range should not be considered for the engine.
