I couldn't quite find the best place for this thread, so I thought i'd go for engine tech...
I came to noticing that my BA XR6 N/A was a little on the low side of oil (12,000km) so just to get me over the line to the 15,000km service I went to my local servo (Shell) looking for some 10W-30 engine oil. Could I find any? nup!
but no 10W-30 as recommended. As I couldn't find any of the recommended oil specification I didn't buy. Now it got me thinking, if I was in a bind, eg: driving an LS1 5.7 litre V8
and I needed a specific kind of oil quickly but I can't find the same specification match, what is the best to do?
Now my *LIMITED* understanding of the numbers are something like the XW number is the viscosity and the -YY number is the temperature that the oil operates okay at? 5W is more viscose then 10W, and -30 has a lower operating temperature range than -40 ?
Something like that? If I had to buy 5W-30 or 10W-40 for my car, which would have been better and why?