Synthetic oil

[Cees Klumper]

I'm pondering whether to use synthetic motor oil in my new engine or to stick to conventional oil. Mobil 1 seems to have an edge in the synthetic department - does anyone have experience with Mobil 1 or with an alternative brand - and what are the cost differences? With as often as the engine requires oil changes, I would like to know that I am getting myself into cost-wise.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[Douglas]

I think one of the added benefits to synthetic oil is longer intervals between changes, Cees. Mine are annual. So while synthetic may cost more, the frequency (or infrequency) of oil changes also has to be factored in.

With that said, I've been very happy with a change to Mobil 1. I didn't wait for a rebuild either. I've experienced appreciably better fuel economy, no consumption, and no noticeable leakage.

Douglas Kim
New York, NY
#018260

[Bob G ✝︎]

I have  been told that synthetic oil on older engines can create oil leaks. I am a firm beliver in Synthetic oils but on my older 1968 SL I have no idea when the engine was rebuild and if it will tolerate it.

Bob Geco

[n/a]

I have heard that synthetic oils in newly rebuilt older engines delay the break-in process; that they reduce friction to such an extent that wearing-in does not occur as it ought to. I know for a fact that Mobil 1 does not work well in Ferraris and that Ferrari dealers and shops recommend against it. Personally, I would run the engine in with nonsynthetic oil to seat the rings etc, then drain the oil, refill with synthetic, run 1000 miles or so, and refill with synthetic. Or you could just start with a good nonsynthetic oil- I use Kendall- and stay with it. Any good oil works fine if it is changed out frequently.
  On a related topic, is there a best oil filter for 113 engines? I have used OEM on mt present MB cars but if there is better I would like to know.

[Naj ✝︎]

Cees,
I use Mobil 1 sport (15w50)in my 280SL with no service history. There are no oil leaks but it did use some oil on the Heidelberg trip which was prolonged high speed driving for 1350 miles.Oil pressure gauge stays up all the way hot or cold. We pay about £25.00 per 4 litres and you need 6 for a change.
I would probably run the new engine in with normal mineral oil and fine mesh 'running-in' filter for 500 miles.
naj
p.s. did you receive a 'tube' I mailed you about a week ago??
naj

naj
'Kloines Scheisserle'
65 230SL
68 280SL

[Ben]

Yep I reckon on a freshly rebuilt engine you should use good quality mineral oil, like 15W/40 or 15W/50. Change it after you start the motor and it has warmed up. After that refill again with mineral and keep using it, changing every 3000, 'till the motor has run in and stopped using oil.

Then switch to a good quality Synth of the same grade. If you have renewed all the oil seals then it shouldn't leak, though maybe a slight weep from the rear crank oil seal but nothing you'll see on the ground.

If you do not know the engines history and it uses oil then I wouldn't switch.

These cars can run rich, more than a modern, so either way frequent changes are a must!

I rebuilt my engine 6 months ago and did exactly the above........it runs great!

Regards,
Ben in Ireland.
'64 230SL 4sp.
'03 CLK Kompressor

[W14]

I have been using synthetics now for 20 years (Amsoil), and am a big believer.  I would definitely use it, Cees.  Break-in the engine on mineral oil for 1000 mi. or so, then use the synthetic.  Change the filter every 6 months, and the oil once a year.  I would rather put your USED synthetic oil in my car than fresh mineral oil (new filter of course)!



Will W14
1965 230SL 4spd
Victoria,BC

[Richard Madison]

Some of these messages were posted by people who speak the King's English and refer to "Mineral Oil"...

Before USA guys and gals start putting "Mineral Oil" in the engine:

"Mineral Oil" in British Speak is "Motor Oil" in the USA. In the USA, "Mineral Oil" is a very thin, colorless, edible, petroleum distillate used as a laxitive and for body rubs. USA mineral oil is not used to lubricate a car engine!!! So in these msgs, Yanks should substitute natural "Motor Oil" where it says "Mineral Oil".
RM  )

[Richard Madison]

Synthetic oil users might want to know that some brands have changed the forumla...there is some controversy about how good (or bad) the new stuff is, flash points, etc. Castrol seems to be changing in some markets, Mobil 1 is not. Synthetic oil mix varies in Europe and North America due to consumer preference and environmental rules.

The chief concern is the use of varies "waxes" in the oil. Some recent rulings allow these "new" waxes to be called "Synthetic"

If you have a clear head, not afraid of a semi technical discussion, and are as smart as a BMW owner (it's on a Bimmer site), read about it here (be sure to use the entire link):

 http://bimmer.roadfly.org/bmw/forums/e24/forum.php?postid=4562662&page=1

Richard M, a non-techie using natural oil (UK: mineral oil) in his precious engine...

[Benz Dr.]

I've been using AMSOIL since 1982 which is long before all the major companies even thought about a product line of their own. This is still one of the very best oils out there.
If you have a leaker it will leak no mater what oil you use. Minor leaks or consuption are of no real concern to me and I really have to question the logic of those with 6K engine rebuild costs being concerned about the cost of oil once a year.
Oil is cheap insurance. Why use less that the best you can get?
BTW. DON'T use STP in your engine. I've been told that it's harmful to the injection pump plungers. Don't know why but but in this case I'm not going to find out.....

Dan c
SL Barn

Daniel G Caron

[Malc]

Synthetics are good, but could be "wasted" on older engines which were designed for the oil of the day, eg 20/50 and alike. Older engine designs do not have the tight build tolerances of today, even if it was M. Benz!
Unless you are doing lots and lots of miles I would stay with a good quality 20/50 or 15/40 and change it and the filter on a regular basis, 6000 miles, or more often if the car isn't used that much
Malc

[tobacco]

For what it's worth, I've been using Castrol Syntec in my Pagoda's M130 since it was rebuilt in 1992.  My mechanic suggested the synthetics' clinging properties are especially good for engines that sit idle through long, cold Northern winters, and he had no qualms about pouring it into the new motor upon which he more or less staked his reputation.  

Often I pop the oil filler cap and check in to see the same uniformly polished, un-etched and thinly coated metal parts I saw 12 years ago.  And every Spring when the engine turns right over after its long rest and the oil-pressure pegs instantly, I smile and figure this isn't something I'm going to change anytime soon.


Bill Greffin
Chicago
#22375