I want to do a review on a very boring subject, motor oil. This is one product which is taken for granted, and not valued until your engine seizes up. Well perhaps we should give it a little more respect.
My car requires 10w40 semi-synthetic oil, which sounds expensive. The good part is that I am a member of a trade club, and can buy this oil at the Main Vauxhall dealers, for just £35 if memory serves! (This is only if you are buying four gallons at a time) This has to be the bargain of the year, and it is genuine General Motors semi synthetic stuff. 4 Gallons seems a lot, but my car needs six Litres per oil change, and I do this every five thousand miles.
The oil is a 10/40, and if you are wondering what this means, read here:-.
To understand the spec, "10" just means that this oil can be pumped by your oil pump just as well as any other single grade SAE 10 oil can be pumped. It matters not whether is is synthetic, or conventional Mineral oil. "W" means that this oil is suitable for Winter conditions, this is because this oil is a Multi-grade, and therefore suitable for use all year. If you have an older car, which will be only started up in the Summer, you will not be needing an oil with the "W" rating. The second number, "40" refers to the viscosity of this oil, measured at 100°C. This is the normal operating temperature, for an average engine during an average driving period.
So there you have it, a boring review over with, hope you were not asleep by the end.