The SAE 10W-30 specification is assigned to low-viscosity engine oils intended for operation mainly in temperate climates, without severe winter frosts. Some of the specialized "energy-saving" oils made in accordance with the requirements of ILSAC GF-5 fall into this viscosity class. It can have any base - mineral, semi-synthetic, fully synthetic. SAE 10W-30 oils cannot be used in engines designed for higher viscosity oils without the risk of a critical drop in oil pressure. This is especially noticeable on engines with mileage, where the oil pressure is already reduced due to the wear of the oil pump, liners and camshaft beds.