240D oil recomendations - PeachParts Mercedes-Benz Forum

harrygrey382 · #1 05-19-2008, 07:10 AM

I was funning 10-40W (diesel) in my 75 115 240D (motor is an early 123 240D one). I was thinking maybe it's on the thin side for summer (in UK). I don't know much about oil ratings, and was thinking 10-40 meant it was 40W when cold and 10W when hot. So I thought straight 30W would be 30 the whole time...

I put it in and my oil consumption is now pretty bad with some pretty solid blowby. So I'm now thinking my understanding of oils is wrong. Can someone explain please?

But my real quetsion is, what's a good summer oil for a 240D in the UK? (temps up 30 maybe, not much and never more). I don't tow, and mainly motorway driving. I was thinking straight 40W, but there is a 20-50W diesel as well. I assume it's important to stick to diesel oil etc.?

#2 05-19-2008, 07:12 AM

Search is the best recommendation. There are many threads detailing what oils are the best.

15W-40 (dino) or 5W-40 (synthetic) are the weights of oil you should use year round.

herring · #3 05-19-2008, 08:03 AM

On that note I recently switched over to Rotella T dino (15W40) from whatever the PO had in there and it is definitely heavier--I notice it at start. It will be fine for now as summer's here (we may hit 40C a couple of days a year in Philadelphia) but I don't think I'd pick this for winter.

harrygrey382 · #4 05-19-2008, 08:31 AM

Quote:

Originally Posted by ForcedInduction

Search is the best recommendation. There are many threads detailing what oils are the best.

15W-40 (dino) or 5W-40 (synthetic) are the weights of oil you should use year round.

thanks. tried the search function and got a lot of oil related threads, mostly on filters and separators. None with the info I wanted though.

So how do the ratings work?

WINGAS · #5 05-19-2008, 10:21 AM

No time to digress on ratings but the lower nujber is the "natural" viscosity of the oil, the upper number is where it moves to under temp.

Diesel or fleet oil have more zinc/boron in them which is important to keep old fashioned valve tappets happy. Use the diesel specifc oil.

bobodaclown · #6 05-19-2008, 10:36 AM

Hmmm.. Not sure if this applies to the UK. But an Oil labeled as CI-4 Plus.
Such as:
Cummings/Valvoline Premium Blue 15W40
Pennzoil Long Life 15W40
Chevron Delo 400 15W40

Just a few.

Palangi · #7 05-19-2008, 08:51 PM

I actually think, strictly from a viscosity standpoint, that 10w40 would be the ideal oil weight for an MB diesel in most North American climates. Unfortunately, with the exception of a few specialty oils, diesel rated 10w40 is no longer made here in the colonies.