Sorry, the engine is a 3.0, car is a 2007 model coupe, and I've not bought it yet. The car has only had one service since new at around 17,500 miles, and has just under 26,000 miles on it now. Not ideal, so assuming the car is OK to buy, I'd be looking to ditch the oil immediately and put in all fresh stuff. This is why I'm trying to get the info now, so I can ensure I put whatever is best for the engine into it when I get it.
Slick, I'm not offended mate, and I appreciate that the guide given was for the USA, but as you say, their conditions vary between very high temps and very low ones, so surely using an oil like the 0W40 (which should cover both eventualities as far as I'm aware) should keep a UK car well covered still? Sure, it won't "need" an oil with a winter rating as low as "0W" for our winters, but from what I understand, an oil with a 0W rating is thinner at cold temps than a 5W rated one, so while we might not get massively sub zero temps in the UK, one would think that it'd still offer more protection than a 5W oil at, say 0 degrees (centigrade), which is a temperature that we do see quite often in winter. Sure, a 5W might not take much longer to warm up and might offer almost as much protection for the engine at 0 degrees, but if the 0W oil is better in this regard when the engine is at its weakest point (most wear) then surely that's a good thing?
Or am I completely misunderstanding the ratings of these oils and a 5W30 will act no different in a Z4 3.0 engine than a 0W40 at UK temps? Or somehow be detrimental?
As I say, I profess to know nothing about oil, other than what I've read online, and what supposed "people in the know" have told me. Therefore, if anybody knows any better than me, please feel free to correct me, as I'd love to learn the differences in these oil ratings and how it'll affect my car.
