Here is a good site with oil info.

http://theoildrop.server101.com/cgi/ultimatebb.cgi

I'm no oil guy but where I live temps can drop to -40.

On a small block chev with a quality mech. oil pressure guage I can see how long it takes for 5w30 dino to make pressure vs. 5w30 synth. and at temps below about -10 F the difference becomes blatantly obvious. If I were cheap I'd run dino in the summer but I can't be bothered.

Here's the bottom line. Mobil 1 Synthetic is O.E.M fill for Benz, Porche, Dodge Viper and GM Corvette. Probally many other high quality auto manufactors. I wonder why that is? Think about it. It's just a matter of cost not if it's better. If you drive your car in the rust belt during the winter (Salt Laden Roads in North America) then the car will probally rust out well before you will see longevity benifits.

Scottfish: Some very inacurate statements in your post:
1)"you will have an extended life of the oil before changing because there is ultimately less wear on your engine.'
You don't change your oil because there is wear in the engine. Your need to drain the oil because it is contaminated by acids, ash, cumbustion by-products, silica, dust, dirt, water and about 10 additional contaminants. Syn. oil will collect those contaminants at the same rate a mineral oil will.
2)Synthetic oil does remain up in the motor longer without dropping down more than standard oil"
All oil, with the same viscosity index (say 10W30)will flow at the same rate, regardless of the make, type or brand. It is an industry standard for which each oil manufacturer has to meet to be allowed to be approved by API (American Petroleum Institute).If Brand X flows in 2 hours, Brand Y will flow at the exact same rate (Synthetic or not)
3) "I can say that the syns do have a certain amount of detergents in them that will help clean the gunk". All engine oil contain some detergent additives but none are designed, added or used or intended to "clean" an engine.
I am not saying Mobil 1 or any other synthetic oil are not good lubricants. All I am saying is that in most normal road applications, they are not better and brings nothing more than a good brand-name regular mineral oils.
JackD

JackD knows exactly what he is talking about. The main I use dino in my Sable changing it every 6-7k and took it to 125k miles without a problem. Enigne ran perfectly when I sold it. I took my 1981 280ZX to 190k miles on dino oil....ran like new.

Synthetic may be a "better" more heat resistant oil but in automotive applications equal performance is achieved by dino oil. This is a case of a marketing investment translating into increased revenues. Ask MB and other high end MFGrs what their oil suppliers pay them to specify the use of Synthetic.

OK most everyone agree's Mobil 1 synthetic oil is superior in all regards. It will prevent wear on engine componets better than dino and it has other benifits. The question really is do the benifits out way the cost. Fictitous EX: You may get 160 K out of your Ford with Dino but you will get 250K with Synthetic. Now your Ford is 12 years old it has 150K on it, It's all rusted and every other part is failing. It's ready for the Junk Yard. Synthetic would be a waste in this case. Conversly you have an semi-expensive sports car that doesn't see salt and put 30K hard miles on it a year. Synthetic could very well prevent an engine re-build for many many years.

I think everyone should read Mobil 1 statment of apllication for synthetic on their web site. They even say it's not always a great investment in all cases.

Most of today's Dino Oil is very good and practicle for most applications, but Synthetic is superior.

Stubman,
Although I compltely disagree that synthetics are "superior in all regards," you make some good points in your post. Cars have many components and systems that can fail and the engine is only one of them. I'm sure that there are plenty of members of this board that have cars with over 300k miles on dino oil.

Let's say that a owner drive their car 300k (not typical) and changes the oil every 5k miles. The car has an 8 quart sump and synthetic cost $4 more per quart than dino. That's $32 a change for 60 changes. The cost is approximately $1920 over the life of the vehicle.

How much more does synthetic actually protect? 0-3% maybe? 3% better would be 9k more miles on a 300k schedule for $1920.

Anyway all I can say is if you are using Synthetic you might as well throw in another $20 a change for Slick 50, then maybe your engine will be left running in the middle of the lane with the rest of you car just a pile of dust on either side.

in my experience synthetic oil isfar superior to dino.

i change my own oil after i had my bmws engine rebuilt i continued to do so. initailly they filled it with dino. and i did too for about 10000 miles. a thorough break in period. then i switheced to mobil 1.

my observations when changing oil was that the synthetic oil still looked "new," smelled less etc etc vs dino oil which had a dark tinge to it and smelt used and had stuff in it.

no scientific i know, but enough to convince me that mobil one is the way to go.

__________________
'O=00=O'
bmw 2002.
long live the legend

Hi All,

Thank You very much for your feedback. I guess, I will stay with the dino oil. I am thinking to use 20W-50 Castrol . Any other suggestions? and do it hot/often. I still have to figure out the hot part without burning my hands.

I do love the car, and I would like to keep it for as long as I can. This is my first MB and I love it.

Thank You,

Sam

__________________
1989 300E, 152k miles
1988 300E, 172k miles


"There is nothing more expensive than a cheap Mercedes-Benz" -unknown

OK here is my 2 cents worth. I'm not a scientist or engineer, just a guy who tries to notice things and to be sensitive to the machines I operate. I became a convert to synthetics riding motorcycles.

On a bike, you've got the engine and transmission right between your legs. On the Japenese bikes I rode, the same bath of oil lubricates the tranny and the engine. When I started using synthetic it was quite noticeable. I could feel the engine revving more freely and the transmission shifted much more freely. It was quite remarkable actually. The stuff simply is slicker than petro based;period. The metal parts will wear less quickly.

As to older cars, that is what I drive and I say, it DOES pay to run synthetic in the older ones. In fact, I would say, the older the ride is, the more carefully I want to protect the engine from wear.

Synthetics. Thumbs up.

__________________
prop up the faith,
whutchens

I've used Castrol GTX for 35 years.

20W-50 in the summer; 10W/30 in the winter

Not saying that you should use Castrol. Just saying it's a good brand of oil that's served me well.

When I gave an '83 Toyota truck to a relative a few years ago, I pulled the valve cover off for one final valve lash check. The upper area was as clean as it was the first time I performed that task. The engine had a hair over 300,000 miles on it and had never been torn down.

It's still running.

Damn!!!! I should have used synthetic all of these years for 4x the $$$.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Hehe. I love these threads.
I switched to synthetic in my Benz many years ago and recorded (I keep very extensive records) almost a 10% increase in fuel mileage immediately. I change it every 5000km.
I had an old Honda many years ago which I bought new. The recommended oil change interval was 12,000km. I was frequently too lazy to bother and often went 20,000 between changes (NuGold was my preferred brand - All the Canadians here will roll their eyes at the mention of that stuff). At 300,000km, I tore down the engine. ALL clearances were within spec. and there wasn't a scratch on any part internally. The bores still showed their original hone marks. I could have just buttoned it back up and thrashed it some more. Oh yeah, it had it's original clutch and rear brakes at that stage too.

Jackd, 1) you do change your oil due to the acids, ash, cumbustion by-products, silica, dust, dirt, water and the other 10 contaminants that get inside in the oil, but a lot of these things you have mentioned are from the wear on the inside of the engine. The ash and the cumbustion by-products are mostly from where the engine is heating the oil up from all of the friction from within.
2) The rate of flow has nothing to do with whether it will take longer to drop down once the motor has stopped because a big factory in this is the heat from the engine working. One prime example is that I have always been a Nissan person. I have always used 10 w 30 in everything i have ever owned. Well, when we bought my first MB, these motors run so much hotter than the normal jap cars that 10 w 30 because thinner than water in the MB. So, I had to go with a little thicker oil. So, heat is definately a factor of how quickly the oil will run off regardless of the type viscosity. When a engine shuts off and is off for 3-4 hours, it has cooled down and there is no heat so the ingrediants in the syns tend to stick more to the sides of the motor, which in the end protects the motor and ultimately is less wear. I agree with neanderthal, the syn oil when changed looks 10 times newer than the standard oil and does not have a bad smell.
3) I never said that the syn oil should be used to clean your engine out, but it will clean a lot of the gunk out if you motor gets that way.

Also, I never meant that a person should use syns on every car out there. Of course, you would not want to use syns on a rusted out junker that is probably not work $1000, but if you have a nice looking car, regardless of make, and you want the engine to last longer, use the syn oil. You may have tranny problems down the road or a mirror may fall off or you may have to replace fuel injectors every few years, I am not saying that syn oil will make the car problem-proof. One example, and not picking on any Chrysler van people that may read this, you will be lucky to get 75k out of a tranny on one of their vans. They are by far the best riding vans, but the tranny's have always been a problem. But, getting back to the subject, do you not think it is better to have a tranny problem or injector problem that requires repairing at 130k and be done or to have the tranny problem or injector problem and then have to replace the engine or rebuild the engine on top of that. I also agree that using syns will will help you get better gas mileage due to the motor running with less friction and ultimately more fuel efficient. For those that still believe standard oil is the best over syns, that is your option, but I will restate that when you are rebuilding your engine due to wearing out, I will cruise on by you and keep going. One last thing, I do agree with Whutchens on that the motor will run smoother with syns. Common sense will tell you that if the motor runs smoother, it will be more fuel efficient, have less wear, and ultimately last longer.

Jackd
A few questions. I was under the impression that synthetic oils allowed longer drain intervals. The oil analysis results I've seen on the diesel forum seem to support this. Also I thought in diesels with turbo's spinning at 100k rpm synthetics held up better. Now do I agree that most people should use synthetics, no most don't keep there cars long enough.

SCOTTFISH, my friend had a 93 Maxima with 190k on the clock. It ran perfectly, used no oil and only one small leak. That car had been a Jiffy Lube car since the warrenty expired. My friend sold it at 200k and it still ran fine, probably would for another 100k. I don't see how synthetic helped you, the next owner maybe but not you. My view is that if you plan on keeping a car for less then 150k, it doesn't matter whats in the crankcase, as long as you change it and it's the proper weight.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Thats about right Hatter. Please note that Synthetic has it's advatages for Turbos that being the Turbo itself. It will prevent coking in a Turbo far better. Another words Turbos can get really hot and there potential for oil burning in a Turbo ( bearing etc.). This is one reason I run Synthetic in my Talon Turbo souped up running 18PSI with about 310 HP @flywheel. Plus I plan on keeping the car for a long time.

I'll put Dino in the 125K 91 300E, but I might use 0w40 Mobil 1 just for the benifit of easy cranking at 0 to -30F and see if I gain a longevity of oil quality to boot.

Synthetic oils are clearly superior to dino oils. The question is, is whether they make a rat's ass bit of difference in the way we apply them. I use Mobil 1 0w40. At this point I am willing to pay the extra $$ for whatever small or large benefit I get from synthetics. I change the oil myself and I think of it as a small treat for my car. Pet owners buy treats for their animals, we buy synthetic oil and chrome thingies.

Most of us change our oil on a too timely basis so I see no disadvantage to using dino oils. These data points of this car or that car going 100m+ on dino oil, add nothing to either sides argument. They are but one point among hundreds of variables in thousands of different applications. And the fact that hi end cars come with factory recommended synthetic adds nothing to the argument on which is better.

A more important question is, are synthetics better in applications where the change interval is significantly longer. Differential oil is left in there for what, 5 years? Tranny fluid is in there for 30m or 2-3 years for most people. I think in these applications, synthetics are clearly the better choice.

glenmore
1991 300CE
1990 LS400