oil change intervals
 

Okay so the manual says every 13000 miles on my 320cdi. That seems excessive to me. So I was wondering what the techs out there thought. I have to use Synthetic which is fine by me. Should I do a change every 4500-5000 as well. Thats what I used to do on the 220D and it never died.
Thanks
m

How often is purely dependent of the type of driving you do. if everyday you hopped in the car and drove say 200 miles on the highway without stopping slowing down or accelerating, I would say yes, maybe, truth is city driving counts as extreme conditions.

Since most of use rarely drive the former exclusively I would recoment the extreme duty recomendation, which is likely 3,000-5,000 miles. Or have an oil analysis run. But don't go 15,000 without doing one.

I concur, 15K on dino oil is way too far... even if you change the filter a few times along the way.

As I recall, oil goes bad when it cools and water condenses in it...

To obtain that milage interval you MUST use an oil that complies with MB spec 229.5 any other oil can't do the distance.

If you closely read MB sevice info they state that drain intervals must be shortened when using high sulfer diesel. I don't know the sulfer levels in US but in Australia they are still relativly high so the drain interval sould be shortened to 15,000km/10,000mi.

Personally I stick to 6000mi on my 87 diesel even thoguh I drive alot 7 days a week, if I had a CDI i'd do 15,000km/6months (both with mobil 1).

Oil is cheap, engines aren't.

If you drive short distances with cold running then shorten the interval, if you sit on a freeway all day then extend it. You have to judge you're driving conditons too.

Seems too long to me, even with synthetic. 10kmi or once a year would be in line with standard practice around here, providing you don't run the engine cold. Peace of mind would be changing the filter half-way through and topping off. And having an oil analysis done if it's cheap ($30) and convienent - call the trucking companies in your area to find out where they have their oil analyzed. You need to do the oil analysis every change.

Oil analysis
 

I am a true city driver. Short runs, low speeds, over 60 mph 1 or 2 times per week. Because of this I have always changed my oil every 3 months/3000 miles. Mostly the 3 months. Since I change at close intervals, what would an oil analysis do for me?

I'm sure MB knows what they're doing regarding oil change intervals. And no, they aren't just thinking they'll start selling a lot more engines if they do it that way. That's why they are very particular on the sort of oil that can go in.
Thanks
David

tomm9298, you and mhingram have two completely different animals. Betcha a donut mhingram paid more for his cdi than I paid for my house. But you do have a good point: oil analysis isn't needed for everybody. I'd be doing it for a high $$ diesel with a long (synthetic) interval. $30 is cheap compared to a new MB cdi. Doing it every oil change means you can track the changes in the engine and determine the optimum oil change interval.

Thanx
 

Thanx DaBenz!! This is my first diesel and I don't want to screw anything up out of ignorance. It's bad enough when something breaks, but when it is your fault by not caring enough to ask...... that is the worst!

Mhingram first of all, you want to make sure you are using a diesel specific synthetic oil, preferably with an API rating of CI-4. If you check your manual, most likely it has as specification requirement. My e300 requires CH-4, which CI-4 supercedes. Most MB dealers will not have this, so you'll have to make sure you get it. The dealer will tell you he has the right oil, and then will just dump in gasoline spec Mobil 1. Diesel specific oil has a different additive chemistry, designed to suspend soot and neutralize the acids of diesel combustion. Use the right tool for the job.
Secondly, high pressure common rail injection is extremely clean and complete burning, which typically lends to longer oil drain intervals. If you use gasser mobil 1, I definitely think 13,000 miles is pushing it. If you were to use mobil Delvac 1 , you could most likely easily do 15k miles on a change. These engines are nothing like the dirty old IDI mb diesels of the past. Even my '99 E300, at 7500 miles into the d1, oil analysis shows the oil is barely worn. Next time I'm going 10k. Oil analysis tests are about $15, not $30 by the way, and that's including a TBN test.. I would suggest running the oil out like I have to 7500, and doing a test, then 10k, then 13k or 15k, and see how the oil is doing. At 422/gal, you don't want to dump this stuff when it's still perfectly good ya know?

Some common high quality diesel synthetics(PAO/Ester synthetic base) are:
Mobil Delvac 1 5w40 (not to be confused with dino Delvac 1300 super)
Amsoil 15w40 Heavy Duty Diesel Oil
Amsoil Series 3000 5w30 HDD Oil
Redline 15w40 Diesel Oil

Some slightly less pure 'synthetics' (these have a group 3 petroleum base)for diesels are:
Shell Rotella T synthetic 5w40
Valvoline Premium Blue Extreme 5w40
Petro Canada Duron 5w40 (best of the bunch)



Tommy9298, depending on what type of oil you're using, oil analysis could give you tangible proof that you are throwing your money in the garbage can and doing the environment a disservice by dumping your oil every 3k miles. Most likely even though you are doing all city driving, and if you're using synthetic, you can easily and safely extend to 5k.

Aus - we have low sulfur diesel here in the states - less than 500 ppm.

Hope this helps guys :)

5W-30 does not belong in a Mercedes diesel engine. Also all M1 synthetics are at least CF rated which is perfectly good enough for light-duty diesels like ours (at least the older ones), but only some of these oils are of the right viscosity.

The cars under warrenty if you change it yourself you might void it! Lightman is right on the new CDI's are a very different animal they burn very clean.

CF rated oils belong in a diesel about as much as a 5w30. I simply listed it because it's a very popular high grade diesel synthetic. I guarantee that anyone who runs Amsoil 5w30 Series 3000 will have better results than ANY CF rated mobil 1 in a diesel engine. You guys that run gasser oil in diesels because you 'can' can go ahead - again I like using the right tool for the job. I personally do not like to use 30 weight oils in diesels myself, but I'd certainly use it before a CF rated oil. I have had great oil analysis results with Delvac 1 5w40 and recommend it to all dieselers.

Plus, mobil has finally released Delvac 1 to mass markets - under the label of Mobil 1 Truck & SUV. At the same price as other mobil 1 ($4.77 at wal mart), it would be stupid to use gasser oil.

Wrong. The right oil for a W123 diesel is a CD-rated oil or better so CF is perfectly fine, but 5W-30 is not on the list. I understand the new diesels specify the latest rating, but I wouldn't say it's more important than the viscosity. Hey, use whatever you want, I was just adding to what you said to clarify the facts for others.

I'm using M1 5W-40 in my W124, and M1 15W-50 in my W123's. Both are excellent oils, but the 15W-50 is a bit cheaper and comes in a more convenient 5-quart jug. Plus I think the higher viscosity is better for the older engines, but that's just my opinion.

Just because the rating CD was specified for the car DECADES ago doesn't mean the old car can't benefit from newer technology, more specific oils. If you want to get technical per MB's 'rules' yes, mobil 1 could be used. Is it the best oil or even recommendable since there are so many other diesel specific synthetics? NO. If someone has a diesel and is looking for a quality oil, they should get one with a CI-4 spec or better - period. The only point I'm trying to make..

This is straight off of mobil's site - and while they agree you COULD use regular mobil 1 in a diesel, they basically say use the right tool for the job. And why shouldn't someone's 20 year old baby get pampered?? :)

"Gasoline and diesel engine oils are formulated differently, but they do have some cross application. This is particularly useful for fleet operations that have a variety of engines. Being able to use one motor oil helps reduce inventory and eliminate misapplication mistakes. But we do not attempt to compare Mobil Delvac 1 to Mobil 1 with SuperSyn™, since they are primarily formulated for different applications. "