There are so many threads on this that it is hard to get a simple suggestion. I think I have received the stamp of approval on the following (inexpensive) oil:
Rotella T 15w-40 (edit: for diesels)

(Last time I checked the "mobile 1" suggestion just lead me to understand that there are many varieties of mobile 1, and all appeared expensive. Surely some of them were not right for our cars.)




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We need zinc for our cams. The best safe short answer is to use any old formula 15w-40 diesel oil.

 

ANNUAL WHICH OIL TO USE QUESTION....

I have been using Pennzoil 10W40 with a bottle of ZDDPlus to replace the zinc. I buy the stuff by the caseload since the east coast distributor is only about an hours drive from my home. Yes, we do need the zinc to act as the perishable metal interface to keep the cams from wearing down.

When I was using Mobil-1 in my 6 cylinder E class I was using 5W-30 weight as I recall. Thats very slippery stuff and it was seeping past the seals and gaskets. When I went back to natural grade which I'm pretty sure was 15W-40 the seepage stopped about 99% almost right away.

During the more temperate months of the years (i.e months with no salt on the roads.......) I use my 380SL as almost a semmi-daily driver, alternating with the Jaguar on nice weather days, so it does get its use. Mostly on open roads. So my concern is least wear and tear internally balanced with the best fuel economy possible. I just don't feel warm and fuzzy about 10W-30 regarding thickness and hot viscosity. I was working for General Motors back in the early 80's when they began recommending 10W-30 for their engines. Introduction of the 10W-30 weight for GM vehicles coincided with the introduction of thte Cadillac HT-4100 "rattlemaster" engine (which may be one of the reasons that engine got nicknamed the Rattlemaster....)

Right now with natural 10W-40 I can go without adding ANY oil at all between changes, and if the car goes 4000 miles the oil level doesn't drop a bit on the stick.

Another thing to consider is a friend of mine who is an automotive engineer told me once (with regard to my thinking of using Mobil-1 synthetic oil in my Studebakers...) that those engines were designed with a certain amount of internal resistance factored in. Full synthetic which did not exist back then would materially reduce the internal friction to a point that he felt was not healthy for the engine.He advised me against using synthetic in my Studebakers and Packards, and I never did actually try it. Our Benz engines are more sophisticated and I believe... did come out after synthetic oils were introduced.

-George-

 

"those engines were designed with a certain amount of internal resistance factored in"
And thus, we don't have Packards and Studebakers any more.

 

Being a fairly new member I'm glad to see this thread. Noticed a couple of light wear spots/lines on the front cam lobe passenger side while changing the valve cover gaskets. Didn't know about the zinc problem.

Would like to read more input on the topic

 

The notorious right cam shaft! Check your corresponding cam follower (rocker), the surface where it meets the cam is hardened to a lesser degree then the cam lobe. It will wear out first and if there are any signs of wear on the follower replace it and probably save your cam.

I didn't notice it on my car until it had a ticking noise......had to replace the cam and all followers. Make sure the inside of your oiler tubes are absolutely clean, if not the sludge/dirt will eventually dislodge and plug up one of the small holes.

 

The current issue of The Star has an article recommending CI-4/SL Mineral or Synthetic for 1947-1975 gas Benz cars as having higher levels of ZDDP. Blended bases are not recommended. For 1976-1997, they recommend CJ-4 or SM oils, again mineral or synthetic. but not blended.

 

Older automobile engines which do not use roller bearing cam / lifter configurations required the zinc in the motor oil to act as a perishable biffer metal to absorbe the friction caused by metal to metal rubbing contact. So collectors of older engine types need to be aware that the lower amounts of zinc in todays oils can be detrimental over time by causing additional wear on the contact points. In the case of Studebaker engines, they used flat tappet solid lifter valvetrains which began to prove vulerable when zinc levels became too low. I use a product called ZDDPlus; you can find it online. When you change the oil, just dump a small bottle of the stuff into your motor oil and it will do the trick. I also know that some guys on the Studebaker forum swore by adding a can of STP Oil Treatment into the oil as it had high amounts of zinc in it as well and did the job. With my Studebakers I always added a can of STP. I don't think it would have the same beneficial effect with a Benz engine as it does with a 50's or 60's vintage engine but I may of course be wrong on that!

 

I'm wondering why everyone thinks OHC engines need the high levels of zinc. I took an engine building class and the teacher was saying zinc is important for pushrod OHV engines as they run high valve spring pressures. The teacher said you can literally burn a cam lobe off in an OHV engine in 20minutes if you don't have the zinc. By design our OHC engines don't run really high spring presssure so we shouldn't need the zinc. I'm sure it wouldn't hurt the solid followers to have it though.

Another interesting twist I learned is that an engine oil can have either good anti-wear package or good cleaning package but you cannot have both. If you load up the oil with zinc the oil won't be as good at keeping contaminants in suspension. Commercial oil is a trade off between anti wear and dispersant properties.

If you really want to choose an oil weight you tune the viscosity by temperature. You want the oil to get hot enough to burn off the moisture. Basically you adjust the viscosity to get the oil the temperature you'd like. You want to use the lightest oil which gives you the correct oil operating temperature, using too heavy on oil will increase parasitic drag on the crankshaft, using too thin of an oil will lower the oil temperature and cause the formation of moisture in the oil.

 

I don't know if you guys know, but oil threads are frowned on here. Where are Nobby & Rowdie anyway?

One of the main reasons I visit the USA for two months every winter, is to buy oil for my cars!

This has been a vintage year for Mobil 1. The local Walmart has everything I need and for unknown reasons, it is all priced at $24.95 per 5 qt jug! That is 1/2 the price we would have to pay in Canada for some versions.

PS: I use Mobil1 synthetic on my 72 SL and no problems with leaks. I use Mobil 1 High Mileage formula on it and different M1 versions on 300D and E320. Even smart car uses M1 5W40.

 

I use Castrol 5W-30 Synthetic in my '88 560SL with 150k miles on it as did the PO. Seems to be working fine for a blended syn. Of course, I'm changing frequently based on time not mileage, I.e every 4-months or so, and usually with only 1-2K miles on the oil. No leaks, no blow buy and no consumption. Drained oil looks good. Maybe I'm lucky don't know but not gonna lose sleep over it either.

 

I'm not 100% certain about the different requirements of OHV vs. OHC engines for zinc. Sounds as though daryn knows something that alot of us may not.

I of course can say that the Studebaker V8's (as well as the Studebaker Skybolt 6 from 1961 onwards) were all OHV engines employing pushrods and not overhead cam. So daryn's remarks would make complete sense from a Studebaker owners viewpoint, not to mention other USA makes with the same technology. On the SDC forum there has been A LOT of discussion about zinc in oil. There have been guys up there who have been driving cars with Studebaker OHV V8's for decades that suddenly were experiencing lobe failure attributable to ZDDP decrease. A new camshaft later and ZDDPPlus or equivelant resolved the problem.

I can understand where in an overhead cam configuration the spring pressures can be lower, but having said that there is STILL pressure there and for my money I'm feeling way warmer and fuzzier just knowing that ZDDP in a higher quantity is there "just in case"
-George-

 

Oil Question

I know we are 3000 miles apart but generally the results are the same older engines wear and if you use synth oil 5-30w etc chances are you will leak or lose oil stick to 10 -40 and you cant go far wrong
:thumbsup:

 

Two words: Brad Penn Welcome!

 

I beleive the whole engine oil industry is basically bullshit.

Clean oil and filter in an engine and change it regularly.

I used Walmart brand oil (which is recycled oil) in my Civic and changed it every 5000kms.

I sold that car with 475,000 kms on it and it still runs to this day.

Yes there is some science behind the industry but I beleive MOST of it is hype in advertising.

And the difference between 10w30 and 10w40...you gonna lose sleep over that?

 

I'm with you Nobby. Not sweat'in oil vicosity, 5W-30 working fine for me, cheap enough ! No leaks, no smoke, no consumption with 150K miles ....:thumbsup:

 

My opinion:

An oil with a high zinc content to protect your cams and cam followers wich are subjected to high surface pressures. Any diesel 15/40 will do, Rotella is fine; I use Mobil Delvac 1300 because it has a higher zinc content.

 

I use Mobil Delvac 1300 because it has a higher zinc content.

Recommended and sold by my local MB dealership.

 

Dogfish IPA, Harpoon IPA (my two favorites that show up), Stella (high alcohol content), and Blue Moon appear in the basement fridge magically

This is certainly a wife to be proud of!

 

Lucky bastard.

 

Now there's a man who'se truly blessed.

-George-

 

Thanks to the fact that our W116 or 117 engines are OHC designs, as long as there is more than "current normal" zinc levels in the oil is probably just fine. We likely have alot more leeway in ZDDP content than owners of older American OHV engines such as Studebaker, GM and so on. Ultimately, I think the length of the valvetrain has alot to do with this issue, and OHC length is very short by comparison!

Probably I can not bother dumping in the ZDDP additive, excepting that I had just bought a full case of the stuff for my 56' Golden Hawk before I sold it and I'll be damned not to use every last drop! Hell----can't hurt.

I think the basic question comes back to viscosity and there's no single right or wrong answer on that one. Methinks that in my climate (northeastern United States) just sticking with natural 10W-40 and keeping to the change routine specified in the owners manual is just fine, and I shoudl stop looking for Communists under bedsheets.....

-George-