Benefits of 3000 Mile Oil Changes - PeachParts Mercedes-Benz Forum

automch · #1 11-19-2019, 08:46 AM

As a professional ASE Master mechanic with 47 years professional experience, I have been told many times that I am wasting resources by changing oil and filters every 3000 miles. My 1983 300SD (which I bought new) now has 574424 miles on it. The head has never been off the engine. The lower sump only removed to replace the turbo drain grommet.

I just completed a 4321 mile trip and my start to finish fuel mileage averaged 28.6 MPG. I added no oil on the trip but is was 1 quart low at the 3000 mile mark when I changed it. She is a sweetheart that has reinforced my belief in good preventive maintenance. I use only DINO oil 15W40 year around even when we are in the north and zero temps and have never not had her start right up. I have found that synthetic lubes will leak where DINO oil did not in customers cars. especially if they have some miles on them so never tried it in my vehicles. Oil and filters are the cheapest parts you can buy!

pawoSD · #2 11-19-2019, 08:58 AM

Oil analysis proves this theory wrong when using synthetic oil. If using dino oil in an old diesel, yes 3-4k changes is ideal. On synthetic on the older ones you can go about 5k before it gets dirty. On the new engines 10k is an easy number to hit with gas engines and even 7-8k mixed driving on modern diesels is just fine.

valvecovergasket · #3 11-19-2019, 11:32 AM

Quote:

Originally Posted by pawoSD

Oil analysis proves this theory wrong when using synthetic oil. If using dino oil in an old diesel, yes 3-4k changes is ideal. On synthetic on the older ones you can go about 5k before it gets dirty. On the new engines 10k is an easy number to hit with gas engines and even 7-8k mixed driving on modern diesels is just fine.

even without synthetic its $25 well spent to get an oil analysis done.

ive been changing the rotella t4 in my om606 roughly every 7-8k

my last report mentioned it being one of the cleanest om606 blackstone had analyzed

granted, this is without egr, but even still... worth getting an analysis before making any interval decisions.

for comparison to a modern diesel, the oil life monitor logic in our new duramax has it asking for oil changes at ~9k miles based on our use (it uses synthetic, and i run T6 in it). ive had oil analysis done on that every time we've changed it, and it still showed it likely had another handful of thousand miles in it.

okyoureabeast · #4 11-19-2019, 11:38 AM

Blackstone told me 5k oil changes on my Dino 15w40 rotella t were more than enough.

Without an oil analysis, this is all conjecture even with 47 years under lifts
¯\_( ͡° ͜ʖ ͡°)_/¯

The best oil for these cars is rendered beef tallow. Pour it into the crankcase during a change and you'll get 4,500 mpg . You can trust me because I've been a mechanic in 10 of my past lives totalling 300 years of experience /troll

Dubyagee · #5 11-19-2019, 11:52 AM

Just had my 2016 Sprinter done at Mercedes and they recommend a 20000 mile interval.

pawoSD · #6 11-19-2019, 12:32 PM

The sprinter has a huge oil capacity and big filter which helps significantly extend the change interval....though if driven a lot in the city I think 20,000 would be a bit of a stretch.

I had blackstone analyze both of my newer engines recently, the Metris M274 gas had 8k on the oil and was still looking great, they said 10k should be no problem at all. It has an 8 liter capacity and I run Liquimoly synthetic. (5w40)

My GLK250 has a 6 liter oil capacity and the analysis I had done with about 7k on the oil also looked good, I could go 10k if I wanted but will probably stick around 7-8k. I run Liquimoly low-ash synthetic diesel oil in that one. (5w30)

The new engines run WAY cleaner than the old ones, that is for sure. The IDI engines of the 61x era really pump the soot into the oil.

tjts1 · #7 11-19-2019, 12:43 PM

Oil changes are for wankers.

Shern · #8 11-19-2019, 01:34 PM

Quote:

Originally Posted by tjts1

Oil changes are for wankers.

I'm with you. I don't even use oil.

barry12345 · #9 11-19-2019, 03:47 PM

Engines I have taken apart that had a steady diet of the Rotella oil. Where spotless inside. That dino oil may be superior to the general run of conventional oils.

pawoSD · #10 11-19-2019, 04:09 PM

Dino oil changed often is fine in older engines....until your trying to crank a 617 or 616 at -10F....then its very not helpful. Synthetic makes a huge difference in that situation.

Screwdriva · #11 11-19-2019, 04:55 PM

Another oil thread. Okay...here we go:

1) Oil Additive : After 15 years of following the best advice on Bob is the Oil Guy, spread over 7 vehicles including 3 Classic Mercedes, two of which are OM61X motors, I have found Auto-Rx to be the king of engine oil additives. The way it liquifies carbon, varnish and sludge is simply the stuff of legend. A before/ after of visible engine components actually highlights shine and I have seen minor oil leaks disappear.

2) Engine oil: I too subscribe to the dino oil theory, especially when running Auto Rx. Once treatment is complete, I switch to Liqui Moly MOS2 to keep start up friction to a minimum.

3) Fuel Additive: Don't ignore these. A diesel purge every 30K miles is great but I have used Chevron Techron fuel system cleaners in the last tank before oil changes for over a decade. Worth its weight in gold!

okyoureabeast · #12 11-19-2019, 06:42 PM

I find this is an effective lubricant for our vehicles:

engatwork · #13 11-19-2019, 06:47 PM

Quote:

Another oil thread.

That is what I thought.

vwnate1 · #14 11-19-2019, 07:07 PM

Quote:

Originally Posted by Shern

I'm with you. I don't even use oil.

?? What about that stuff in your hair ??

(SARC.)

Those who don't run well past 100,000 miles will never understand the concept that oil gets dirty sooner than it wears our so there is a long term benefit to the 3,000 mile oil & filter change .

These same folks do cold oil changes and think nothing of consistently running 30,000 miles on and oil change and not adding any in between because "it's FINE ! go test drive it, it's parked right out side !" .

Those of us who actually do internal engine repair know better .

Oil threads are fun because most think whatever is in their whip now if the very best ever .

Graham · #15 11-19-2019, 07:36 PM

Quote:

Originally Posted by engatwork

That is what I thought.

Yeah - Couldn't believe we have another one! Must be a newby so far as forums are concerned.

I actually just did an oil change on my 300D.
Bought two large jugs of Delvac 1 Full synthetic 5W40 on sale.
Poured one in, no sign of oil on dipstick yet.
Poured 1/2 another one in. Still no sign.
Kept adding until both jugs were empty. Just showing.
Checked oil capacity from manual - 8L.
Checked large jugs. Turns out they had put 1USgallon (3.78L) in a 5L jug!
No wonder price was good!
Added some regular 5W40 synthetic I had to bring level up.
Note to self. In future RTFL.