Quote:
|
Great. Use the oil they recommend, you will be providing a good minimum level of protection. The reason I recommend using the manufacturers specs is that one oil does not fit all engines. For example a moderm turbo charged engine requires a completely different oil to our old engines. Even though the Rover engines did not change much over the years, the recommended oils in the manuals for various temperatures appear to have changed. Mine states that 40 is good up to around 35C and then use 50.
|
There is nothing I would love more than to use the exact brand and weight of oil that is specified in the owner's manual. Unfortunately, it is not available. I can find Castrol GTX 10W30, but it does seem too thin for the summer and I don't know that Castrol GTX is the same as "Castrol" that the LR are recommending. It also has no ACEA rating.
That's why we have so much trouble with this in North America.
Why would I use a 15W oil? Well, similar to your argument about summer weights, I'd think that 15W oil would have lower cold viscosity in the summer when it's 40-60 degrees at night, compared to the recommended 10W which is intended to be used at much lower temperatures.
Castrol GTX 10W30 seems like the best I can do in the winter, and 15W40 in the summer.
