OK to mix oil grades? - PeachParts Mercedes-Benz Forum

jeansain · #1 11-15-2004, 03:08 PM

I'd like to use Mobil 1 0w40 but can't find it here in Toronto. I am thinking of using a mixture of 5w30 and 15w50 (maybe 75/25 respectively). In Toronto, the coldest it gets is usually -20° Celcius (-4° F). Opinions?

TIA

mwaller · #2 11-15-2004, 04:27 PM

I don't know the answer to your particular question, but I know that some oils can be mixed and others shouldn't. You might try posing your question on one of the forums at www.bobistheoilguy.com -- those folks know a lot about oil and oil analysis. Many of them mix oils to get a desired viscosity that isn't otherwise available.
Good luck!
Mika

manny · #3 11-15-2004, 04:56 PM

Quote:

Originally Posted by jeansain

I'd like to use Mobil 1 0w40 but can't find it here in Toronto.
TIA

I buy my 0 W 40 from the local M-B dealer ( Kitchener ).
It's about $ 8.50 ( CDN ) per liter.
Personally, I would not mix different weights of oil, not even the same brand.

BigBenzWV · #4 11-15-2004, 05:13 PM

I just did 5 q 15W-50 + 2.5 q 5W-30 of Mobil 1. I am in WV.

jeansain · #5 11-15-2004, 06:39 PM

Quote:

Originally Posted by BigBenzWV

I just did 5 q 15W-50 + 2.5 q 5W-30 of Mobil 1. I am in WV.

Have you done this before or is it the 1st time?

jeff-abalone · #6 11-15-2004, 06:45 PM

I will not mix oil too!!

In BC, the MB dealership has Mobil 1 0W40, but I will perfer Lubro Moly 0W40.

dakota · #7 11-15-2004, 10:50 PM

There is nothing particularly wrong with mixing viscosities, despite what some have said. The problem is that you never really know what you get. You can't just average the weights and volumes and come up with the resultant viscosity. It's much more complex than that.

But one problem with your mix is that I don't think Mobil 1 5w30 is an approved oil for MB engines. As near as I can tell, in North America, the only two viscosities of Mobil 1 available and approved are 0w40 and 15w50.

While the Mobil 1 0w40 would probably be best for you in winter Canada, the 15w50 weight has a pour point of -45°C and a -37°C pumpability temperature. Easily suitable for your climate.

#8 11-16-2004, 05:23 AM

If there is a Wal-Mart or Costo nearby, they may have the oil you want.

jeansain · #9 11-16-2004, 09:16 AM

Quote:

Originally Posted by dakota

There is nothing particularly wrong with mixing viscosities, despite what some have said. The problem is that you never really know what you get. You can't just average the weights and volumes and come up with the resultant viscosity. It's much more complex than that.

But one problem with your mix is that I don't think Mobil 1 5w30 is an approved oil for MB engines. As near as I can tell, in North America, the only two viscosities of Mobil 1 available and approved are 0w40 and 15w50.

While the Mobil 1 0w40 would probably be best for you in winter Canada, the 15w50 weight has a pour point of -45°C and a -37°C pumpability temperature. Easily suitable for your climate.

Very interesting! Thanks.

I'd never have thought however that the 15w50 would be suitable for canadian winters. But after reading your post, I Google searched and double checked it at the following site: More Than You Ever Wanted to Know About Motor Oil and you're absolutely right.
So I'll just use the 15w50.

Thanks again!

Hatterasguy · #10 11-18-2004, 11:18 PM

inetd are you changing your lifters finally?

0w-20

omg that stuff is like water! Maybe 0w-40 would be a better choice? Call me old school but I don't like 0w oils. I would run 5w-40 Delvac 1 if I had a M119.

jeansain · #11 11-19-2004, 09:46 AM

Quote:

Originally Posted by inetd

I've pulled 3 popped oil bridges off my 140 so far, and two MB shop mechanics blamed this on high viscosity {too thick} oil. In my case it was 15w50 Mobil 1. It's just too thick they claim. Hell, it was too thick back in the summer in Georgia, much less winter in Canadia.

I've gone to M1 0w20, as the lube qualities of syns are so far superior to any dino. Super thin syn viscosities are all the rage around here, even in the summer. I agree.

Now I am all confused!

However, I'd never go with 0W20. Way too thin I think.

I went to Mobil's website and here is the quote for my car:
"10W-30 Good for temperatures from -4° F to 50° F
You can use Mobil 1® with SuperSyn™ 10W-30 with confidence".
But apparently that this viscosity is not approved by MB: USA: Approved Engine Oils for the Latest MB Engines

More confusion!

Aside from 0W40, what synthetics are everyone using??

Hatterasguy · #12 11-19-2004, 10:08 AM

Jeansain what weight does your manual say to use? I always go by the manual.

I think inetd ment 0w-40 for his S500 that seems to be the oil of choice for a lot of people.

Hatterasguy · #13 11-20-2004, 05:21 PM

So you did mean 0w-20? What does it offer that 0w-40 does not? MB recomends 40W oil in most of their cars and a lot of the other Euro cars do. I know on older engines 0w-40 has been known to cause low oil pressure. I can see the difference on my guage when using 5w-40 vs 15w-50. But I have a 603 a very different animal than the modern gas engines.

Do you get your oil tested? I would be interested if you get more wear metals with the 0w-20 vs 0w-40.

No I don't have a S600 my good friend does. But W140's are temting. Their is a nice 1997 S420 and a real nice 95 S320 in the paper both for $16K!

manny · #14 11-20-2004, 06:05 PM

0W-20 is the recommended oil for the newest Ford, and possibly Honda engines.
A lot of controversy in the Automotive Industry about that one.

Hatterasguy · #15 11-21-2004, 07:37 PM

I still would like to see some lab results, because the Germans that designed M119's were pretty smart and if they could have went with a 0w-20 they would have, it would have improved fuel mileage.

A few usuers of 0w-40 on older engines reported higher wear metals in their oil. I'm not saying 15w-50 is the right choice either but maybe something in the middle.

btw 2.5 bar is at idle? Thats real high btw. It should always peg when you hit the gas.