What does HD stand for in motor oil?
Simply so, what is SAE HD 30 oil?
Valvoline HD Engine Oil SAE 30 is apremium conventional, heavy-duty motor oil, for use ingasoline and diesel engines where the engine manufacturerrecommends a single grade motor oil.
Similarly, what does W mean in oil? The "w" in motor oil stands for winter.The first number in the oil classification refers to a coldweather viscosity. The lower this number is, the lessviscous your oil will be at low temperatures. For example, a5W- motor oil will flow better at lower temperatures than a15W- motor oil.
Besides, what do the numbers mean on motor oil?
The numbers represent the viscosity of theoil and the W stands for WINTER. The long answer: In a 5W-30for example, the number before the W describes the viscosityof the oil at low temperatures. The lower the number,the thinner the oil and the better the oil's coldtemperature/ cold start performance.
Should I use thicker oil in a high mileage engine?
The slightly thicker oil film from theheavier base weight oil — 10W — can helpprotect worn engine bearings as well. Over the decades ofbuying and driving older, high-mileage vehicles, I'veeven used 15W-40 and 20W-50 oils in high-mileageengines to improve oil pressure and extend their servicelife.