j1b3h0

Just got my '88 560 SEC out of the shop for an oil change and some other things. The shop asked and I specified synthetic oil. Well, after I picked up the car, I asked what kind of oil. Castrol Euroblend 5w-30 was the reply. Though I don't wish to stir the endless debate about syn vs. dino (especially in higher mileage cars), my reading of the owners manual specifies 5w-30 wt. only when it's 14 degrees F or colder-unlike the SF bay area where this car lives. When I balked, the shop guy said they put it in everything these days and MB recommends it even for my car in these temps. Any truth to this, or should I change the oil pronto? Oil press seems normal, drops at idle when warm to just below 2bar. Car doesn't leak, 171,000 mi.

evita

Hi,you are right 5-30 is for a quite a different climate.
For SF region ,just add Oil additive (STP) and dont push your car until it is the time for changing oil.

cdplayer

I live in Sacramento and my daily driver is a 1984 500SEC with 262,000.
My mechanic,a former MB service manager, specifically recommends 15/50wt for these high mileage older cars. Synthetic on the newer engines; dyno on older models.
I currently have Mobil 1 synthetic. Really cleans the engine sludge out. It has done such a good job that I now have a small oil leak that wasn't there before. Engine sludge had kept the oil at bay.
I will be using Castrol GTX on my next change. This may increase compression a bit. I have been told that synthetic may not fill in the wear tolerances of the older engines and some oil will be lost through blow by.
I need to find that out myself.

jhodg5kc

I'd strongly recommend running Delo or Rotella 15/40 diesel oil in your gasser. M1 and the like are great, but pricey and can be considered a bit of overkill.

I like the diesel oil for a few reasons, one, it does an Astounding job of cleaning out engine internals..being that it's designed to carry all the particulate etc that a diesel produces dealing w/ a gas engine is nothing.

2nd, all the new oils for standard gas cars have had their zinc levels lowered considerably. Zinc is a very good lubricant and our engines were designed with it in mind. It has been removed from said oils as the zinc is hard on cats. Diesels not having cats the zinc levels are still @ the older levels, thus keeping cams/mains etc kosher.

3rd, you can pick up either of these two quite reasonably...anywhere from 8-9$ a gallon.

Jonathan

harkgar

Are these oils sold under the names Rotella and Delo or under Castrol or other name brands? Do they come only in 15W40 or other ratings? I have a 1986 560 SEL and I have used both mineral Castrol diesel oils and Mobile Supersyn oils. With the synthetic stuff the engine seals leak more though the engine seems quieter. The heavier non-synthetic stuff makes the engine leak less. My catalytic converters are still great passing emission tests with flying colors.

BENZITCH

Hi Johnathan
Diesel oil in gas cars?
Can you elaborate on the reasoning? I know you think these things through, and just don't follow the crowd.
BENZITCH
Cousinbruce from MBCOUPES.
Rotella 15/40 diesel oil in your gasser. M1 and the like are great, but pricey and can be considered a bit of overkill.

I like the diesel oil for a few reasons, one, it does an Astounding job of cleaning out engine internals..being that it's designed to carry all the particulate etc that a diesel produces dealing w/ a gas engine is nothing.

2nd, all the new oils for standard gas cars have had their zinc levels lowered considerably. Zinc is a very good lubricant and our engines were designed with it in mind. It has been removed from said oils as the zinc is hard on cats. Diesels not having cats the zinc levels are still @ the older levels, thus keeping cams/mains etc kosher.

3rd, you can pick up either of these two quite reasonably...anywhere from 8-9$ a gallon.

Jonathan[/QUOTE]