Engine: D5: Which Oil?

[Cameron1590]

Thanks Chaps, appreciate the help.

Going to take it back and will get the 5w-40 Shell oil which I believe is A3/B4.

Thanks

[smk70]

The recommended oil grade is quite wide for UK temperatures. This is shown in the car hand book .5W40 is fine The important spec is ACEA B4. I have used Eurocar parts Triple QX syn plus 5W40 in mine and it is on 302000 now. The 0W30 grade is more to do with fuel economy than any affect on engine wear.

[AndyV7o]

Originally Posted by smk70

The recommended oil grade is quite wide for UK temperatures. This is shown in the car hand book .5W40 is fine The important spec is ACEA B4. I have used Eurocar parts Triple QX syn plus 5W40 in mine and it is on 302000 now. The 0W30 grade is more to do with fuel economy than any affect on engine wear.

Kind-of, though to be A3/B4 the oil must have a HTHS value of greater than 3.5. Now, the number is irrelevant as far as the layman is concerned but I included cos it helps give something to focus on, but what this essentially means is that regardless of the static vicosity of 30 or 40, both oils are effectively the same 'weight' 'thickness' however one wishes to perceive it when/where it is under load in the engine. This means that the pumping resistance and flow through tight apertures is largely the same, as is the stability and integrity of the 'cushion' of oil the crankshaft, conrod, camshaft journals 'float' upon within the bearings. This is where A5/B5 comes in with lower hths to enhace the economy (and why A5/B5 shouldnt be used where an engine isnt designed for it).