I can see 3000 mile intervals on cars that putz around town,because every car as far as I know that came with a little book in the glove compartment is being driven under severe operating conditions. At least that's what it says in the little books.People always look for low mileage cars, but I personnally won't buy a car that mostly hung around town unless I can get it for cheap.Every time you take off from a stop, the burning gasses have to slip around the top ring,get behind it, and push as hard as possible to force it to seal against the cylinder wall. That's where the wear comes from. Once you get 3600 lbs moving you could cruise on 2 cylinders. Also once you lock up an automatic trans, you are just moving fluid around. Around town friction material is being asked to do its job everytime the tranny shifts.Brake bands are applied and released hundreds of times. We all know what happens to an aluminum can when you bend it back and forth enough times.At any rate I change the oil at the recommended 5000 mile interval on the one car I may never get rid of; my 83 300TDT. I'm getting ready to do the 315,000 mile scheduled service,and the car fires up on cold winter morns and has plenty of power. In my opinion products like DELO (diesel engine lubricating oil) are necessary on over the road tractors because of the incredible loads they are subjected to;
I've used plain old car oil for years in all my diesels, but then again my cars usually never go less than 25 miles once they are started.I also have a double ended quick disconnect key chain with 2 keys for the wagon.It sets in the driveway next to the 560 because the garage is filled with a 67 230SL and a 71 3.5 280SEC which are both used to storestuff on. Getting back to the 300TDT, I fire it up about 10 minutes before my wife goes to work,leave the key in the ignition and lock the car with the other one. she drives off with car at operating temp. I think this adds to the longevity.

Peter

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Auto Zentral Ltd.

autozen,

I agree with everything you say except the Delo reference. Delo contains additional soot dispersants and detergents that are specifically designed for diesels. If you were talking about the synthetic universal grades with their extremely high price I would understand the hesitation, however, I buy Delo for only a few cents more per quart than standard oil. It is great insurance for very little more.

Additionally, the farther you extend your oil change interval in a diesel, the more valuable the universal grade oil becomes.

My $0.02,

Delo must be good oil. The guy that delivers my paper drives a VW rabbit diesel with Delo oil that has over 400,000 miles with lots of stop and go driving. He changes it once a month regardless of miles. The engine sounds like new. It would be hard to make an argument against using this oil and changing it often.

However with the oil analysis that I have had done does show the synthetic to be superior even at the extended train interval. I also never have to worry about the car starting in cold weather. The mileage increase of 2 miles per gallon pays for the oil in 10,000 miles.

Excellent logic Larry B on your posts,most people are not aware that additives get used up. I fully agree with you & hope that others follow suit.

Tigerfox

Oil change intervals seem based more on miles now rather than time.

Question - what if you have a diesel and it only gets 1,000 to 2,000 miles put on it a year. Using dino juice, should one change every 6 months, 12 months, etc.. Does the oil deteriorate when not in use? I want to be eco minded, but I do not want to ruin the engine either?

Any thoughts appreciated - Ron

Condensation builds up in the oil. My recomendation is every 6 months OR whatever milage interval you decide - whichever comes first. Take the oil to a recylcing center and get the most out of your motor

-brian

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Brian Toscano

I use an all fleet oil ..I have for years.. Now its Delo 15-40 in every thing I own.. I change my motorcycles at 2000 miles.. in normal use.. I sold an 82 Yamaha Venture that I put 280,000 miles on and had no problems..It now has over 300,000 miles on it and still has no problems.. The Goldwing 1500 w/Champion escort sidecar that replaced the Venture only has 50,000 miles on it.. The 1500 Vulcan Classic FI that replaced the 82 Honda 650 Night Hawk with 180,000 only has 10,000 on it.. We put over 450,000 miles on our 240 Diesel.. 400,000 thousand on our 250S. and some where near 300,000 on our 300CD.. On all them you could still see the paint on the valve springs when you adjusted them.. The engines were clean inside.. used very little oil..

Last week I helped a friend adjust the valves on his 77 300D.. I had done it before and the engine was clean inside.. He has switched to a Syn oil.. and now says he changes every 8000 miles.. The engine was not clean inside.. Had like a layer of sludge on the springs and inside the engine.. He said it has been that way the last two valve adjustments.. It seems to run OK.. I did mic. a few of the cam lobes and could see no wear.. I have to wonder how much he is going to save by not changing oil and filter over just doing at the 3000 mile mark and using a dino oil.. For the difference in price between the dino oil and the syn oil you can change the dino oil every 3 thousand and to break even you have to change the syn oil every 10000.. Cost of 3 oil changes with filter with dyno oil is.. 63 bucks.. Cost of one syn oil change with filter is 71 bucks at the prices we pay at the local Shucks for oil.. Filters at 7 bucks each .. And the savings is??????

I think I will stick with what I know works.. There is no question that the Syn oils are better oils... But these old engines were not well vented.. and did not run as clean as the newer engines.. I wonder if that will not bite us in time..

Ken

To me the best reason to use synthetics is to extend the drain interval. I am commuting 750 miles a week and just got fed up with changing oil all the time, so I switched to synthetic (Walmart housebrand synthetic) and 10,000 mile intervals. Walmart also has Rotella 5W40 synthetic and I am going to switch to that next time. I might even increase the interval again. I seem to remember when Mobil ! first came out they said one could go 25,000 miles between changes. Well, that didn't last long because someone quickly figured out they were going to be selling a lot less oil if everybody started doing that. I will admit there is a psychological benefit to changing oil and the more often you do it the more "feel good" there is.

Hi Ken,

I can't help but wonder if your friend didn't change the filters early and often at the time he switched. Generally, when switching to syn on an old engine, the filter is changed much sooner the first time or two because the syn lube will pick up deposits left by other oils and the filter will filter them out, quickly sluding up the filter. I've often heard recommendations to change it at 1000 miles (or sooner) the first time. Sounds like he did not do this.

My '87 300D is a newer engine design. I switched it to syn when I bought it at 185Kmi. Now it has 261Kmi and no problems. I can see all the factory paint dots on the cam, etc. I've heard that using syn vs chevron 15w40 will cut down on timing chain wear, quiet down hydraulic lifters (okay, you don't have those), allow better cold starting, ...

Happy Holidays

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Brian Toscano

I am not familiar with the terms Universal and Standard relating to oil...They were in Larry B's post as pasted below. I just bought a 85 300D and will be changing to synthetic due to easier starts and less wear in the winter. In talking to Rusty he mentiond not to go straight to synthetic but to do a blend for the first two oil changes to get the engine used to the synthetic for numerous reasons not stated but it makes sense to me. I am also looking into the Harvard filter but will still change the filter every 3k miles regardless of the type of oil used and will probably change the synethic oil every 5k period. However....my main question is the universal and standard difference and is blend a good idea as have seen it mentioned on some thred that it is not good. I will not be using any oil that is not API CH-4 4 rated and from what I have read will go with Delo. Since this is a low mileage car I am getting(for me anyway) I want to keep it clean and long running. I presume when discussing Delo, you are referring to Chevron DeloŽ 400 Multigrade Heavy Duty Motor Oil. Thanks for your thoughts. I am a bit new here and appreciate all the experience and sharing .
Jon

Jon,

Unless the previous owner used a heavy duty diesel oil such as the Delo 15W40 or Mobil 1300 15W40 (both excellent compared to Rotella) then the engine will start cleaning itself, so be sure to change the filters early and often the first few times! 1000 miles or so. I don't see a reason NOT to mix them. He's saying that(probably) because it will conceivably loosen less deposists at a time. Plenty of people change to 100% syn all at once without trouble though. Whatever you do - Delo or syn - change the filter BEFORE the first oil change, unless the first oil change is at 1000 miles... You may want to run Delo 15W40 for 1000 miles once or twice and then go all syn...

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Brian Toscano

Brian...Thanks and that is good advice....I will do the Delco first....I also will plug it in...as love to have that engine warming soon after start up. I have done this with three previous desiels and had great luck. I am also a filter and oil nut and will change the first filter about 500 miles...and the oil maybe about 1500. I know it may not be necessary but I like to do it and would prefer to over do the filter and oil than under do it. It takes the question out of it as to am I doing it right. (I think) It was a good answer for Rusty to I feel as he did not have any idea who I am or how I like to do things so he was in a way offering sound advice. I prefer to loosen the dirt slowly...and will drive the miles necessary to have the first change done in a week....I don't need a reason to be in the MB cockpit...lol...I just love driving these cars...
Thanks for your answer. It was a good one..
Jon

P.E.,

I'm very happy for you. The way I see it, they're your cars and you should take care of them the way you see fit. I'm sure you don't mind if I do the same.

Have a great day,

Funny how the booklet that originally came with my '83 300SD shows Castrol GTX as a recommended oil, but the rating on recent quarts of GTX is SL. Either way, I've always used GTX 10W-40 in all of my cars, and when available I use Agip lubricants. I have considered the switch to Mobil 1 in my 300SD, but have decided that good old dino oil is doing just fine with 3,000 mile changes. I do use Mobil 1 in two of my cars, the ML320 and the 380SE but all the others get GTX 10W-40, and the TR6 gets GTX 20W-50.

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Regards,
Aaron

Aaron,

As mentioned, the CF rating was dropped from many mineral oils in the early to mid 90's to meet the newer Sx ratings such as SL. Synthetics can meet both SL and CF, but most mineral oils cannot.

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Brian Toscano