Engine: B5244: Can I use 5W-40 synthetic engine oil in my 2002 XC70?

[barrybritcher]

we dont know what engine he has so cant be quoting oil spec.

for example t5 is a5 b5

[eVolved]

Originally Posted by AndyV7o

Nowt wrong with 0w30, or 0w40 over here either. The first number is better lower wherever really, and the latter needs to meet the engine requirements at operating temp.
It isnt just down to viscosity there is also hths, if you have two oils, say 0w30 and 0w40 or 5w30 and 5w40, 5w30 and 0w40, etc etc, that both have an hths of say 3.6, these will (should) both behave and protect the engine the same where it counts in the main bearings and extreme heat areas regardless of how viscous they may be at 100° (which is where the latter number is measured) which is why a lot of modern and manufacturer specs specify an hths value rather than a strict grade. For example GM Dexos 2 which can be owt from 0w30 to 5w40. This is why spec is important.
So, if these engines didnt receive any tolerance changes internally, make sure the oil is A3/B4 ideally or C3 if not and you can be assured the engine is protected whether its 0w30 or 5w40.

Thanks. Yes always use same Castrol brand at full synthetic A3/B4.

[eVolved]

Originally Posted by barrybritcher

we dont know what engine he has so cant be quoting oil spec.

for example t5 is a5 b5

Hi Barry, it’s a T5 (B5224T3)

[barrybritcher]

Ok so it's A5 b5 spec

[oragex]

I'm in Canada, we get up to 35C in summer time and down to -25C winter time (less lately with the climate warming). Engine 2.4 non turbo, used Edge 5W-40, then Edge 0W-30 and now Pennzoil 0W-30. Have to say, I have no way to tell for sure if an oil does good or bad to the engine as I can't measure engine wear and didn't test the used oil either. All these oils appear to work fine, only possible difference is the Edge 0W-30 would allow the engine to warm up faster in cold weather, while the Penn 0W-30 'appears' to give better mileage (but may well be only an impression). Have to say of all these oils, the Edge 0W-30 did stay by far the longest without getting dark, not necessarily a scientific test. But for very hot climates year around, the 5W-40 may be the better choice, particularly if one also likes to hear the engine singing at higher revs now and then