If my memory serves me right. In general the owners manuals states change the oil every 7,000 miles (or so) or 6 months which ever occurs first for normal driving conditions. It wasn't until your quick oil changers started to pop up (Jiffy Lube & others) that they started promoting the 3,000 mile oil changes. I wonder who benefits from that.

From what I have been told that the oil itself doesn't wear out, but the additives in the oil wears out. That's why a 6 months intervals are recommended regardless of the miles because the deposits in the oil will eat away at the additives in the oil. That's why when changing the oil it is better "Change oil hot" to flush the deposits.

One concern I would have using synthetic oil. Would be having the same oil filter on the car for all those miles. I would think one would want to change the filter at least once in between oil changes.

I'm a boater who changes the oil at the end of season when I winterize the boat (around Nov). I also change the oil when I commission the boat in the spring (May). Because of the deposits that were in the engine that got flushed into the pan (eating away at the additives in the new oil for six months) when the oil was changed in the fall. The reason I change the oil in the fall also is so the deposits are not sitting there for six months eating away at the bearings and other internal engine parts. But I'm sure not to many boat dealers/marine mechanics would agree with this.

I also had a mechanic that once told me you cannot change the oil enough. Meaning you can only do good by doing so. I'm sure when you change the oil you can feel/hear the difference in the motor.

By the way I just discovered this site and it's great. I have 1973 280 that I'm getting ready to try to restore and I'll have plenty of questions.

Thanks

Excuse my ignorance. The above was my first post and it was meant to be a reply post for the other oil change post.

Thanks

Hello,

I use Mobil 1 15w-50 on all 3 of my diesels. It works great. I change the oil AND filter, every 4,000 miles. Supposedly they say it lasts 25,000 miles, but there is no way I am going to leave the same oil in my car for that long.

As long as you use a good filter (I use OE MB filters) and a good motor oil Mobil 1 synthetic (supposedly the best in the industry). The only downside is the cost. At almost $5.00 per quart and 8 quarts, plus filter, it costs more than your typical oil change.

I kind of wondered about the (owners manual-7,000 miles vs 3,000 miles-jiffy lube). I think its better to change it more frequenty than wait 7,000 miles. Also your driving habits, driving conditions, etc.

On the car you are restoring, do you plan on doing a complete engine overhaul? Because I heard its not good to use synthetics on a older car with a lot of miles. And you are right about how the additives wear out, etc.

Hi Mr. Chan,

I do plan to rebuild the engine. I have also heard that it's not good to use synthetic oil in older cars,but I don't know about rebuilds. I don't use synthetics anyway because I do change my oil quite frequently and because like you pointed out the cost.

Mike,

What model car do you have?

Yes, if you don't reach the mileage it is very important to change at six months or so. Not only are the additives used up, but you are probably taking short hops which do not warm the oil enough to boil out the moisture.

Have a great day,
Larry

Larry,

It's a 73 280 Sedan. It's actually not in that bad of condition. The car belonged to my father who past away not to long ago. So it has sentimental value to me.

It has some minor rust and dings. It also has some carb. problems. From want I have been told that the MB carb. is great when its working. But after it gets some age on it. It's a constant chore to keep it right. I'm thinking about a Weber or Holly conversion kit for it.

You are right about the short hops. I never thought of the moister in the oil not boiling away. Good point.

Thanks
Mike

Mike,

I certainly understand the sentimental value that is attached to this car. If it were mine I wouldn't let go of it unless my family was starving.

7,000 miles is not an uncommon factory recommendation. I think that you have to take into account that most people drive a car a few years and trade it off. For the average driver 7,000 mile intervals will most likely keep the engine healthy until the original owner gets tired of driving it, or the next shiny new car catches their attention. For us folks who want to drive them forever, 3,000 miles or six months is a good rule of thumb. As to who benefits, you do by having ensured engine life. Oil and filters are cheap, engines and cars are expensive. My $0.02.

What carburetor does it have, I guess I missed it somewhere. Does it have a couple of Zeniths?

Take care of this car and keep it exercised.

Have a great day,

[Edited by LarryBible on 01-05-2001 at 06:56 AM]

Solex 4A1
 

would be the carb that he is cursed, er, stuck, aah has on his 73 280. More tempramental than my ex-wife.
But, as long as it isn't warped, I guess its rebuildable...kits can be had for just under 70 bucks.
I am still looking to "rent" a Solex for my 73 280 that I sold to a guy in Texas. I just need it to get onto the transporter, and back off again. Maybe 5 or 10 minutes of actual use.
Good Luck with your restoration, and watch your head when your under the hood! :D
-Larry

oil change
 

The manual on my 93 400e says to change both oil and filter at 7000 miles under normal driving conditions.

Under severe driving conditions, it says to change the oil each 3750 miles and the filter each 7000 miles.

Apparently, the particulate load in the filter remains the same during all driving conditions, but the oil is used up more quickly in short trips and stop and go driving.

Jack

ocpdba,

Oracle database administrator?<g>

You are correct in your research on what MB says. The oil is not really used up, it's the additives in the oil that are used up. Additionally if you are taking short hops, you are not boiling out the moisture in the oil, and acid is also created.

The MB intervals are meant for the vast majority of folks who buy a new car, drive it a few years and trade it. I'm sure that their recommendations will accomplish this. If you fit in this category, follow their recommendations. If, however, you wish to run your car to high mileage, you need to forget that you ever read that information, use quality oil and change oil and filter often.

Good luck,
Change oil hot and change oil often,

Yep, high tech Oracle junkie. Gives me something other to obsess about than the beloved MB 400e.

I bet that 240d with a speed is much better than the auto. My parents had a 240d. A great car, too slow, probably really WILL last forever, however. Why is it that the slow ones seem to last longer? Wouldn't it be great if the ratio of engine longevity to horsepower was direct instead of inverse? The faster a car was, the longer it would last. We could all justify buying a 500e that way.

I do not have personal experience or scientific evidence that changing the oil at 7k is any different with regards to the longevity of a car than changing at 3k, do you?

I would love to see numbers on this subject instead of trusting the manual.

ocpdba,

Yes, as I've said in another post, I've seen timing chain stretch in recommended interval engines versus OCD interval engines, it virtually does not stretch in the OCD engines.

The original engine in my 240D went 380,000 miles with 3K oil changes. It actually was still running pretty good, but the rear main seal had worn to a point where it was no longer touching the crankshaft. It would have been dumb to pull the engine and ONLY replace the seal. It was pretty impressive what everything looked like. I took apart another 240D with 200,000 and recommended interval oil changes that was really worn out.

I reitierate, however, for most people the recommended interval will provide satisfaction.

Have a great day,

Hello Mr. Michalek,

If you do plan on rebuilding the engine, then it wouldnt be a bad idea to use synthetic oil. They say if you use synthetic oil when the engine is new, it will help the engine live longer sort of speak.

I would change it at least twice a year even if you dont drive it too much. I understand what you mean about sentimental value, sorry to hear about your father.

Regular oil dirties up, contains wax, and just doesnt really protect better than synthetic when it comes to cold start, etc. You can visit http://www.mobil1.com for more info. If your going to restore your car and want it to be the best, you mine as well invest in that little extra and have the best oil in there. The only concern is I dont know if you can use synthetic in an 73, I would imagine you could though.