I used Mobil 1 5w-50 in my 997 Turbo. It as well as Mobil 0w-40 are really great oils with lots of protection as Ive come to discover reading on this forum. I know a lot of you stand behind it.

My question is,

I have an 07 Jag XKR.. its Oil Specs are

"API SM and ILSAC GF-4, and further suggests using 0W-30, 5W-30, 0W-40 and 5W-40.

For climates ranging from -35°C (– 31°F)
to + 50°C (+ 122°F), the following oil
viscosities may be used:
0W–30 will protect from -35°C (– 31°F) to
+ 35°C (+ 95°F).
5W–30 (preferred) will protect from -30°C
(–22°F) to +35°C (+95°F).
0W–40 will protect from – 35°C (– 31°F) to
+ 50°C (+ 122°F).
5W–40 will protect from –30°C (–22°F) to
+50°C (+122°F)."


Even though 5w-50 is not listed on the factory spec sheet, do you think it is still safe to use this grade or should I stick with what is recommended in the manual and go for the 0w-40?

I live in Florida where it can get quite hot, so im really partial to Mobils 5w-50 which is quite popular around here..

Thanks..