Which motor oil for a Volvo 940dl ? - jaynm
I have a 1992 940 dl sedan automatic What grade oil should I put in it I just bought a month ago and I am unsure?
Which motor oil for a Volvo 940dl ? - PaulFromMelton
Autodata recomends 10W/30
Which motor oil for a Volvo 940dl ? - GregSwain
10w40 semi-synthetic. It's what any service centre would chuck in it.
Which motor oil for a Volvo 940dl ? - yorkiebar
Imo depends on the condition of the engine, the mileage and the type of use, but would think 15/40 (autodata alteranative moderate climate recommendation) assuming it has done a fair mileage.
Which motor oil for a Volvo 940dl ? - Dynamic Dave
The following link has been posted in the past.

www.castrol.com/castrol/sectiongenericarticle.do?c...1

Look for the link "Find out which oil is best for your car"

A quick look up on the castrol site suggests 10w/40
Which motor oil for a Volvo 940dl ? - GregSwain
Typical Backroom - ask a simple question about oil viscosity, and get 3 different answers. Basically, I wouldn't put 10w30 in an old engine because it's too thin....either of the other 2 should be fine. It's a tough old Volvo, so oil thickness won't make a huge difference.
Which motor oil for a Volvo 940dl ? - Cliff Pope
The question isn't clear whether you mean for the engine or the gearbox. The specific mention that its an automatic suggests the latter.

In my view the type of engine oil is far less important than that it is changed frequently and that you use a proper oil filter with the anti-drainback valve.
I switched to a 20/50 at 200,000 miles. It does make a difference - the timing gear is quieter. I use the cheapest oil I can find, but change it every 3000 miles, and replace the oil filter every 2nd or 3rd change. The car has now done 352,000 miles, and runs as well as ever. (Volvo 240 with B200F engine)