i have a 94 E420 with 42K miles. i don't know what the previous owner was using, but since i had a car at 39K miles, i am using synthetic.

i think newer benzes have an indicator that tells the owner when to change the oil. mine doesn't. so, should i change the oil every 3K miles? i've never owned a mercedes before so i don't know if it's any different. also, i've never owned a V8. does that make any difference?

thanks

There are loooong discussions on this under the search button, but I think the general consensus is for any engine, (US, Japan, German, whatever), and for any number of cylinders, change oil and filter while hot at 3000 mile intervals. Some argue that the synthetics last longer, but to me dirt is dirt, no matter how slippery the oil in which it is suspended. I change oil this way on my celica gts, and so far the engine has lasted 280,000 hard driving miles. Hope this helps.

My prediction for this post is;
A: someone will reply "hey do a search! it's in there ( or is that the RAGU commmercial? :D) )B: Larry Bible will remind you that you can't go wrong by "Change it HOT and change it OFTEN"
C: Could go on for another 12.43 posts :D :D :D !!!

I choose 'B' as the right answer!

Change oil hot and change oil often,<g>

Changin' it often...
 

Personally, I plan on installin' two 50 gal. drums. One full of oil hooked up to the pick up tube, and the other with a 12V suction pump in the lowest part of the pan that goes to the other 50 Gal drum that is empty. Oh, and the full drum will have a level sensor from a fuel tamk to tell me when it's getting low. I should get close to 1 billion miles from my car, don't you think? :D ;)

Seriously though, I remember being told at some point in high school (we're talkin' the late '50's) that changing your oil too often wasn't good for the engine. But then, I was also told that you didn't need to change your oil filter every time you changed the oil, because the filter's capacity for trapping contaminents exceeded the amount of media created during a regular oil change interval. So the recommendation was: oil change, three months, or every 5,000 to 7,000 miles. Oil filter, every six months, or at every other oil change...

Incidentally, in a recent conversation with a technician at RedLine, I was told that their recommended oil change interval for their synthetic oil, when used in a Mercedes diesel, was 10,000 to 18,000 miles! (Somebody get a respirator for Larry Bible, please!) :eek:

And, the local MB dealer where I live told me that the oil change interval on the newer Mercedes models "have been vastly extended due to cleaner burning engines with fewer emissions and a greatly reduced amount of contaminents being introduced into the engine's lubrication environment." :rolleyes:

Finally, a local "pleasure boat dealer" that was a recent client of mine for a while uses an 12V electrically powered oil extraction device similar to the TopSider for all oil changes on ALL OF the boats ($30K to $125K) they service.

They simply warm up the boat's engine for 5 minutes, stick the pump tube down the dipstick tube, and suck all the oil out. But, they also change the oil on the basis of engine hours, not miles.

But, before the TopSider guys out there get envious, the pump-oil-into-a-5 Gallon Bucket rigs that they use cost $165.00. :eek:



[Edited by longston on 01-04-2001 at 12:17 AM]

speaking of hours...
 

How many hours are there between oil changes on a marine engine? And, might this not be a better indicator for oil change intervals, due to the fact that some people endure traffic (idle time at lights, etc.), wilst others have the pleasure of missing such a great time (well, until you tourist show up anyway, and drive slow in the left lane looking lost, with a map infront of you, and McD's boxes on the console :D)
Anyway, before I get carried away, has anybody thought about changing their oil based on engine run time? (besides the 3 month interval)

FYI, Larry I disagree with you. Changing oil too often IS bad for the engine.

I am really curious - why would changing the oil too often be bad, and how often is too often? What is the mechanism of the problem caused by the frequent oil changes?

Too often is like less than or at 2,000 miles (conventional) I think. This is what my mechanic told me (MB Master Guild - 6 time award winner).

DSinger,

I enjoy your posts very much and have respect for you. But I'm afraid that I have to disagree with you AND your mechanic. You CAN change your oil too often, but it doesn't hurt your engine, only your wallet.

Actually in some applications 2,000 mile intervals may not be near enough. If you are driving very short distances, like a 5 or 6 mile hop to the office, you are not warming the oil enough to boil out the moisture. In this case you need to be changing the oil about every six months or less, rather than by mileage.

I'm still very anxious to hear WHY nad HOW extremely frequent oil changes hurt your engine, except for the extra wear on the drain plug and oil filter bolt threads as well as the hood hinges.

Respectfully,

Reply coming...
 

I will consult with my tech and get back to you as soon as possible with a full and thorough explanation...

Will too-frequent oil changes wear out your wallet or your drain plug threads first? :confused:

I have oil and filter changed in my fleet at intervals outlined in the Owner's manual, and adjust for climate and driving as best as I can. Our cars go 30-40 miles each time they're started.

Of all of my problems in all of my vehicles over all of the years, not one would have been prevented by a more frequent oil-change interval. Now if I can just figure out how to keep other drivers from turning or stopping in front of me without warning, all I have to do is look up the proper interval to change head gaskets... :D

And the oils they are a'changin..
 

This continually recurring thread will likely be voted as the subject most often discussed and rehashed on this (and probably every other automotive) forum.

Larry Delor, the average recommended oil change interval on pleasure craft is every 25 to 40 hours. The actual average boat owner probably changes theirs between every 50 to 75 hours. Like every other internal combustion engine all of this is determined by whether the boat is towing a skier (or several skiers) at an average sustained 3500 to 5000 RPM, or cruising around a body of water, or just trolling. :)

The average recommended oil change interval for commercial diesel engines used in trucks and buses is between 10 and 15,000 miles... :p

Larry Bible, I'm too damn lazy to search the archives for one bit of information, when I can get it direct from "the Bible". What oil brand and viscosity do YOU use in your vehicles? ;)

Incidentally, EVERY boat mechanic that I asked said that they use dipstick tube draining devices because they HAVE to. Not one of them told me that they ever use one for their own cars. However (do I hear a growing rumbling, grumbling sound from the "TopSider" users out there?), they all agreed with LB about performing a second suction the morning after removing all of the oil the day before, with the caveat that it should be done when the ambient air temperature is above 70°F to compensate for the oil having cooled off. :cool:

So far everyone agrees that:

1. You should change your engine oil regularly.
2. The oil should be changed while the engine is hot.
3. The filter should always be changed along with the oil.
4. The oil should be responsibly disposed of at a recycler.
5. You should never mix synthetics with dino-broth.

Correct? Any disputes on the above list? Good! :D

Everything else, IMHO, is open to opinion, and subject to variation based upon conditions present, type and duration of operation, and personal preferences. :D

But, I do still wonder what the deal is with equal oil change intervals being recommended for both gas and diesel engines. (I also wonder why diesel fuel costs more than premium 92 octane where I live, but thats another thread...) Shouldn't the change interval differ for two such radically different engine types? They do in commercial applications. :confused:

Oh man...here we go again! I change my mind I am not going to say a word....

longston,

I use Chevron Delo 400 15W40 in everything including the lawn mower, except my new car which gets Mobil One 10W30.

I agree with your list of agreement except the last one. In an obscure thread months and months ago, there was some reference about mixing synthetic and dino. There was someone responding who was in the oil industry and sounded very knowledgable. He said that part of oil specificaiton is mixability, and that there was nothing wrong with this mix, and actually some to ge gained.

This mixability also applied to any SAE spec oil mixed with any other. This was a shock to me, but I have no reason to doubt him.

JimH,

You are in the same situation as myself. It is extremely rare that my cars don't go at least 20 miles every time they're started. This does allow extended oil changes. To help it along, a hot thorough drain is good measure. I am a fanatic oii changer because I have had such good luck with it in the past. When it does come time to open up one of my engines they are always as clean as can be and you never find any crud even packed in the ring grooves.

I wish I could help with the unpredictable drivers, I guess frequent oil changes can't do much good for that.

Thanks everyone for your comments,

[Edited by LarryBible on 01-04-2001 at 07:50 PM]