Engine oil

[Nicholas Lewin]

Since owning my 240 (B230F) I have been changing the engine oil twice a year

I put in 10W40 in the summer (Volvo's recommended oil) and I put in 5W30 or 0W30 in the winter (and yes I change the filter, the sump plug and sump plug washer too)

You might say overkill, especially given the low mileage I do and the stressfree life the car leads - that's not my question

In my head, using a lower viscosity multigrade oil in the winter is surely a good thing? The oil will flow easier at lower temperatures and so lubricate the engine quicker starting from cold. Clearly in the summer, you need something that will cope with higher ambient (and possibly operating) temperatures

So, why wouldn't I run with 0W40 all year round? In that case, given my annual mileage of about 5k miles, I'd probably only change the oil annually

Thoughts fellow 240ers please

[AndyV7o]

Im not a 240 owner, but 0w40 all year should be fine in terms of viscosity (I wouldnt use a w30) as 0w cold is still thicker than 40w hot, which is what you have at full temp.
However, what is the year? If its between 70's and 90's you dont want to be running modern oils in it, they dont have necessary additives which are needed in older engines, thus will shorten the life as wear will increase. In older engines you need an old spec oil to properly protect them, the most modern you ought to use is a basic A3/B4 with very few other, older approvals/specs, otherwise investigate 'classic oils' for cars of that era.
You should also be ok with a basic 5w40 synth such as Gulf formula G, Fuchs Titan Supersyn, Shell Helix Ultra, which have older specs, a 5 still flowing better than a 10 when cold, but correct vis when hot.

[timetrip]

I have A b200f and B230f and i use 15/40 mobile....as you cant get Duckems anymore.....never had any problems with oil...

[AndyV7o]

15w40 will have a fairly appropriate spec, so yeah you shouldnt have any real issues. So long as 15w is permitted otherwise the oil pump will be overloaded and circulation too low when cold.

[timetrip]

yes i agree,,,but mine have had 15/40 for the past 14 years with no problems......yet,,,lol

[jetronic63]

I use a 10w40 and change annually (with filter) and have done for the past 11 years. This grade is recommended for ambient temps of -20 to 40C and and UK almost never gets outside of that range. My understanding has always been that the wider the operating range of a multigrade, the more viscosity modifiers it has to have added and the less stable it is at higher temperatures. So it seems to make sense (to me anyway) to stick with the 10w40 as it does everything I need in all UK temperatures. The only note that Volvo make is that at higher workloads, a 15 or 20w40 is recommended (probably because of the possible breakdown of viscosity modifiers I guess).