Oil Change Timing Question (distance vs. time)
I'm getting an indicator for scheduled maintenance (Svc. B), since it's past a year since the last one, but I'm wondering whether I can wait it out for a little while. Thanks for your opinions.
DIY cost you nothing, oil + filter cost you 40bux at MOST.
don't give your car too much care if you gonna sell it.
love it if you are gonna keep it forever
It probably won't hurt anything. You've heard the rest of the arguments, and I'll spare you. It's a great sign that your oil gets darker with use. It means it's doing its tertieary job (after lubricating and cooling), which is to suspend contaminants. If you ever see your oil getting lighter, that's the time to panic. It would mean it's lost its ability to keep that junk floating, and that it's washing up somewhere on your engine's beach.
For the OP: if your oil is getting fully-used, heated all the way to operating temperature and run for at least fifteen miles on most trips, you're okay to run it the full mileage. But if you're only rolling to the market, shutting off and driving back, up your changes.
Best rule: if you're feeling guilty about your oil, go ahead and change it.
Now, let's get back to something we won't squabble about. Like, how to raise your kids.
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go check the service/inspection list between Service A and Oil change then you'll know service A is just a waste of money.
think the dealer would have any leverage on warranty issues if i dont have A done?
the timer in my car reads only days left till A is needed. (annoying!)

As alluded to by others in this thread modern highly detergeant/dispersant oils should darken - they are doing their job
Short trip vehicles should be given a good run from time to time to evaporate water out of the oil which can build up to a couple of percent if engine seldom runs at full operating temperature for long enough.
Stick to MBs maintenance schedule. There are time related issues with hygroscopic products like brake fluid which should always be changed on time - (read the manual) - There are also issues of warrantee & negative effects on resale value should scheduled servicing be ignored. Maybe resale is less effected in the USA but where I come from a full service history adds big bucks to the resale value of a Merc
Last edited by Glyn M Ruck; Jun 24, 2008 at 09:27 PM.

This information was obtained for a summit between auto makers in the late 70's when as you all may or may not remember when the import cars mainly japanese were outlasting the american vehicles something like american engines getting 100K max and imports like 170 or better this was because of one reason the filter, american cars and the manufactures were around 12microns and the filter media was that junk paper sort of what it is now, the imports were using like 5 microns and better material, now of course as stated above the retro kit filters use fiberglass material and metal as the media and provide 3-5microns of filtration.........its worth the investment.........and to finish the summit story the agreement was for the american manufacturers to start producing oil filters with better filtering capabilities because of the lopsided auto industry.
Last edited by jhartmac; Jun 25, 2008 at 12:27 PM.

This information was obtained for a summit between auto makers in the late 70's when as you all may or may not remember when the import cars mainly japanese were outlasting the american vehicles something like american engines getting 100K max and imports like 170 or better this was because of one reason the filter, american cars and the manufactures were around 12microns and the filter media was that junk paper sort of what it is now, the imports were using like 5 microns and better material, now of course as stated above the retro kit filters use fiberglass material and metal as the media and provide 3-5microns of filtration.........its worth the investment.........and to finish the summit story the agreement was for the american manufacturers to start producing oil filters with better filtering capabilities because of the lopsided auto industry.

This is an unfortunate post because it is belligerent and only partially correct. It put an end to useful discussion. Lets revive it. The commentary on oil filtration is mainly correct
There are three major reasons for changing oil:
1) The oil is contaminated. Dust - fuel soot - combustion by-products etc. Here good filtration can extend the useful life of the oil by the removal of particulate contaminants. Conventional filtration cannot remove contaminants that are miscible in the base oil or liquid or it would strip out the additives. Thus water and fuel contamination as examples are not removed by filtration
2) Additive depletion. In simple terms some additives are used up (sacrificial), such as those that neutralise acids formed in the combustion process, and others simply wear out. Viscosity Index improvers, which are milled polymer are chopped up under conditions of shear in the engine. Long drain oils can have additive treat rates in excess of 18% - they have a finite life
3) Base oil oxidation which leads to thickening (sometimes offset by fuel dilution) which ultimately results in breakdown and polymerisation.
Synthetic oils are not fake or a scam and are synthesised from a host of building blocks which could be petroleum derived but also from a host of other sources, gases, coal, esters of substances etc. I'm keeping this simple because we are already going well beyond what the consumer is interested in. They are synthesised from small molecules and tailored to give totally predictable characteristics. Petroleum based products unfortunately, even after refining, retain molecular structures and many undesirable characteristics of the crude oil they came from.
The no fuel shortage story if synthetics were real is nonsense. Synthetics are expensive to produce and that while synthetic fuels are produced in, for instance, the Sasol process (Coal gasification) they are not viable in global terms.
Synthetic oils have many benefits over their conventional petroleum cousins and I will list but a few below - If people are really interested in a long dissertation - which I doubt - we can start another thread.
a) Synthetic base oils contain no unstable molecules so they have inherently excellent oxidation stability that reduces degradation at high temperature and gives long stable life, lower additive treat requirements & lower wear
b) Synthetics contain no wax like petroleum products and thus do not become thick or solid at low temperatures. This low temperature fluidity allows easy cold starts with minimum wear
c) Synthetic oils have a very high viscosity index - that is they thin down far less for a given rise in temperature than do petroleum based oils. This means they maintain viscosity at high temperatures without the addition of high volumes of unstable VI Improver or Viscosity Modifiers
d) Synthetics have low volatility (NOAC values) which prevents evaporative loss & thickening.
e) Synthetics have very high thermal stability leading to excellent lubrication under conditions of high temperature high shear giving low wear in highly stressed areas such as cam & follower
f) Lubricity, Film Strength & good Fuel Economy are other attributes.
A good synthetic oil will perform for longer in service and will reduce wear to almost negligible levels. Observe Mercedes Benz service periods & service product recommendations for the long life of your investment.
Last edited by Glyn M Ruck; Jul 3, 2008 at 06:47 PM.
city driving puts a lot more stress on your engine then highway.
Most modern oils can last a pretty long time, your filter will go bad before the oil. Hence why mercedes uses special fleece filters now.

This is an unfortunate post because it is belligerent and only partially correct. It put an end to useful discussion. Lets revive it. The commentary on oil filtration is mainly correct
There are three major reasons for changing oil:
1) The oil is contaminated. Dust - fuel soot - combustion by-products etc. Here good filtration can extend the useful life of the oil by the removal of particulate contaminants. Conventional filtration cannot remove contaminants that are miscible in the base oil or liquid or it would strip out the additives. Thus water and fuel contamination as examples are not removed by filtration
2) Additive depletion. In simple terms some additives are used up (sacrificial), such as those that neutralise acids formed in the combustion process, and others simply wear out. Viscosity Index improvers, which are milled polymer are chopped up under conditions of shear in the engine. Long drain oils can have additive treat rates in excess of 18% - they have a finite life
3) Base oil oxidation which leads to thickening (sometimes offset by fuel dilution) which ultimately results in breakdown and polymerisation.
Synthetic oils are not fake or a scam and are synthesised from a host of building blocks which could be petroleum derived but also from a host of other sources, gases, coal, esters of substances etc. I'm keeping this simple because we are already going well beyond what the consumer is interested in. They are synthesised from small molecules and tailored to give totally predictable characteristics. Petroleum based products unfortunately, even after refining, retain molecular structures and many undesirable characteristics of the crude oil they came from.
The no fuel shortage story if synthetics were real is nonsense. Synthetics are expensive to produce and that while synthetic fuels are produced in, for instance, the Sasol process (Coal gasification) they are not viable in global terms.
Synthetic oils have many benefits over their conventional petroleum cousins and I will list but a few below - If people are really interested in a long dissertation - which I doubt - we can start another thread.
a) Synthetic base oils contain no unstable molecules so they have inherently excellent oxidation stability that reduces degradation at high temperature and gives long stable life, lower additive treat requirements & lower wear
b) Synthetics contain no wax like petroleum products and thus do not become thick or solid at low temperatures. This low temperature fluidity allows easy cold starts with minimum wear
c) Synthetic oils have a very high viscosity index - that is they thin down far less for a given rise in temperature than do petroleum based oils. This means they maintain viscosity at high temperatures without the addition of high volumes of unstable VI Improver or Viscosity Modifiers
d) Synthetics have low volatility (NOAC values) which prevents evaporative loss & thickening.
e) Synthetics have very high thermal stability leading to excellent lubrication under conditions of high temperature high shear giving low wear in highly stressed areas such as cam & follower
f) Lubricity, Film Strength & good Fuel Economy are other attributes.
A good synthetic oil will perform for longer in service and will reduce wear to almost negligible levels. Observe Mercedes Benz service periods & service product recommendations for the long life of your investment.
DIY cost you nothing, oil + filter cost you 40bux at MOST.
don't give your car too much care if you gonna sell it.
love it if you are gonna keep it forever
There are three major reasons for changing oil:
1) The oil is contaminated. Dust - fuel soot - combustion by-products etc. Here good filtration can extend the useful life of the oil by the removal of particulate contaminants. Conventional filtration cannot remove contaminants that are miscible in the base oil or liquid or it would strip out the additives. Thus water and fuel contamination as examples are not removed by filtration
2) Additive depletion. In simple terms some additives are used up (sacrificial), such as those that neutralise acids formed in the combustion process, and others simply wear out. Viscosity Index improvers, which are milled polymer are chopped up under conditions of shear in the engine. Long drain oils can have additive treat rates in excess of 18% - they have a finite life
3) Base oil oxidation which leads to thickening (sometimes offset by fuel dilution) which ultimately results in breakdown and polymerisation.
4) The actual molecular structure of the oil is destroyed mechanically as they are cut at severe pressure points such as the valve stem/lifter and camshaft/follower interfaces.
On the topic of synthetic fuel, yes it is indeed possible. All it takes is money; lots of it. Think in terms of at least triple current gasoline prices, and maybe more.
We do not currently have production facilities for synthetic fuels, so these would all have to be built. This would take many years; and again, lots of money.
At some point, I believe synthetic fuels will be viable. But this will not happen tomorrow, nor even in the near future. Other fuel technologies are a lot closer to reality.







