John, the diff fluid was changed. No further repairs were recommended but only because the techs apparently didn't even glance at the car. They didn't notice it was silver, they didn't notice it had a four-cylinder instead of a V6.. I'm not sure how they'll find their way home from work if the birds ever eat those bread crumbs.

 

I really can't stand the dealership experience. They're constantly trying to fleece me on stupid stuff like brakes, air filters, spark plugs, and anything that isn't even half way worn at highly inflated prices.

Beating the crap out of the loaner (passive aggressively) and chatting w/MILF's while drinking K-cups just isn't my style.

in 2007, passengers side cat failed. Knowing the tactics that the 3 Mercedes-Benz dealers in my area engage in, I brought it to an Indy shop first to get it diagnosed at about $130 before going in for warranty.

With diagnostic sheet in hand, I was curtly told that they do their own testing and reminded that only authorized Mercedes-Benz dealers are allowed to make diagnoses and that it would save me time and money by going to them first in the future.

Without even addressing the issue they suggested $1000 in basic maintenance.
and another $1500 in repairs that existed before the bumper-to-bumper-warranty ran out and that they never mentioned or documented previously.

After firmly holding my position, I let them fleece me on the air filters at $127 since they replaced both my L+R cats.

In 10years of ownership, I haven't spent no more than $12,000 max on maintenance/repairs mainly through the 4yr/50,000 mile free maintenance, and doing most repairs myself while judiciously extending intervals as long as possible and deferring it wherever possible.

This includes opportunistic sales like when Autozone runs specials on Mobil 1, or when I can get 12 Bosch 9652 iridium plugs for $36 after rebate.

 

I hope this is at the dealer experience and not at me.

 

No, that is at you Matt

Of course it is at your dealer experience

 

US dealers seem to suck!

 

<sigh> I honestly don't know why I have such a good relationship at the same dealership.

However, I also feel sure that it revolves around the fact that I only deal with 2 SA's and that my Coupe has been worked on by exactly 1 technician since it rolled out from under warranty. A standing friendly relationship with the service manager is also in my corner, I guess.

That being said, I have to admit that while I was in for emissions and stuff with my wife's car Friday (her's has seen a couple of techs, but still only 2 SA's) they (to their credit) found the relay that has caused an intermittent problem with the power seats (covered by the extended warranty) and -- apparently pulled something loose while they were replacing the relay under the steering column and now the Voice Control doesn't work. I'll be back again this week. As long as they get it resolved, I won't consider it a negative experience.

 

Small wonder that you go to your Indy! Besides their being so good, your stealer sounds pretty bad. My only complaint is the price of everything. So far, they seem to have been competent, but I'll limit my exposure to them - except for my wife's car which is a CPO.

 

They say an educated customer is your worst customer and when it comes to cars, I am spot on.

I remember buying an Acura in late 2001. Honda manual has reasonable conventional oil change intervals of 5k/6months severe conditions, and 10k/1yr for normal driving with oil filter changed every other cycle.

Lo and behold, less than 2 weeks after buying the car, I get a letter from the dealer advising me that in their experience, intervals of 3750k are best given the harsh 4 season New England weather up here. *******s.

If it weren't for the fact that most of my trips are less than 5 miles with heavy stop and go, especially in winter, i'd extend intervals to 25k or more. Mobil 1 0w-40 is really that good and is practically bulletproof.

 

I'm not sure I'd agree with M1 0W-40 being bulletproof or capable of 25k miles, not based on my analysis. But it is definitely good for 13k intervals.

Mike, I'm just not willing to be at a dealer enough times to establish any sort of relationship. They always inevitably disgust me. They assume you are stupid and you have to get nasty with them to show them otherwise. Why can't they assume you know your stuff first and then adjust to people who don't? The SA looked me in the face and told me they inspected my car for leaking cam sensors and then immediately handed me paperwork on my "2007 white C230". He himself took the VIN off my car, did the inspection for damage prior to the car being taken back to the service department.. how does one miss this? He just assumed I would take his word for it.

As for the techs, they changed the diff fluid on my car. The cam sensor thing was on the RO. They looked at the paperwork that said "White 2007 C230", looked at the physical car sitting there that was a silver 2005 C230, then decided the paperwork was the right thing to go by? IDIOTS!!!!!!!!!

My indy admittedly completely dropped the ball on the transmission flush recently, filling with a final 5 quarts instead of the 4 they had removed. But they know I know my stuff, they take me at my word, treat me with respect, are grateful for my business, and charge a fraction of the amount of a dealer. And the few mistakes they've made in 10 years of using them with literally a dozen different cars have always been corrected without further issue.

 

Oil change frequency is subjective and is dependent upon driving style and conditions.

I looked at your blackstone report dated 10.25.2011.

I'm not an expert on oil and have little clue as to what the results entail, but statistically, your shortest and longest interval of 12.6-13.4k don't have enough variance with respect to the data points to warrant any further investigation.

If those were my results, i'd be comfortable extending intervals by 20-25% and then retesting.

Does the mothership publish guidelines on acceptable results on used oil properties? They obviously test the crap out of this stuff and have scientific evidence locked up somewhere to back up their oil change recommendations.

 

Glyn is the oil man. The 13400 result was "starting to show its age" according to the blackstone report. 20-25k miles would not be pretty.

 

I'm sure the data is locked up in some vault and considered proprietary data, but what are some min/max acceptable values for "oil properties" on that blackstone sheet with respect to the Mercedes engines used in W203. I'll do a search at bob the oil guy's site. What are some min/max values for acceptable oil characteristics?

I'm trying to quantify hard numbers and science here to justify/determine interval frequencies.

I'm of the opinion that the M112 with larger sump capacity and naturally aspirated can run longer intervals than your engine.

 

Hey the stuff turns into sludge eventually without a doubt.

 

The chemistry and synthesis suggest that sludge will be the least of your worries given the uniformity and super strong nature of the carbon chains. they're super duper stable and the conversion process has existed for about a century now.

The innovation has come from engine manufacturers working in close concert with oil manufacturers designing and customizing packages for longevity and optimal wear characteristics. Seems that with companies like Honda comfortable with 10k/1yr conventional oil change intervals, that synthetics can go MUCH further dependent upon additive package consumption.

Modern filtration and ventilation in engines is top notch! I'm considering ordering a 6 pack Blackstone lab test kit at $19 per hit and testing the oil at 13k (baseline), 17k, 20k with adjustments depending on results. Along the way closely monitoring base oil characteristics like flashpoint, viscosity and contamination.

I might throw in some extra additive package along the way in consultation with experts in the field to protect drivetain components. If indicated, I may also swap out the filter.

The m112 is a solid and conservative design with generous sump capacity. it can handle a test like this.

My goal is to see just how much additive package I can toss in before the base oil gives up.

 

I'd rather you do this testing on your engine rather than mine.

I'm into making my engine last a long time , not my oil, even if it does cost another 100 bucks a year.

Looking forward to seeing your test results.

JC

 

Most base oil change intervals on arbitrary and unsubstantiated evidence and assumptions rather than any hard scientific data. Manufacturer recommendations always err on the conservative side and even so, many from the dealer on down second guess the manufacturer

Furthermore, even mechanics who know the operation and principles behind a modern 4 stroke engine have very little idea of the chemistry and science that goes into oil.

My goal is to test the crap out of this oil and along the way find minimum acceptable wear characteristics on Mobil 1 0w-40 in conjunction with my driving habits/seasonal changes with respect to the M112 engine.

Seems to me too many pamper there cars in a quixotic attempt to extend longevity and for preventative maintenance when the car will become uneconomical to repair past 200k anyway.If an avg oil change costs $100, changing at 20k rather than 10k will save you $500 and a boatload of time and about 30-40quarts of oil and 5 filters over 100,000 miles.

This past weekend. changed out spark plugs at 25k interval (Denso IK16) and spark plug wires. Old wires tested out fine and looked healthy at 90k and 10years. Old plugs looked good and i'll save them since i don't think plugs really have a finite shelf life.

Point is, owners and even most enthusiasts perform unnecessary maintenance even second guessing manufacture recommendations in the process.

It's not a money issue, it's more a question of methodology. When brake pads squeak, time to replace. When brake discs don't meet minimum thickness time to replace them. Same with tires.

Glynn, i'll do a search since i'm sure you've been asked before, but if you feel like humoring me for the purpose of this thread, post it again and the methodology you use when determining optimum intervals.

 

Most industrial concerns take part in PM's ie Planned Maintenance. They find it more efficient & economical to the bottom line compared with running machinery into the ground & failing at inconvenient times.

I like to think car maintenance runs along similar lines. I rather do maintenance a little early than be caught on the side of the road.

By the way , I trust automotive engineers to tell me the limits on brake rotor thickness & tyres . Not a nice way to find out that you are wrong when the disc collapses at 100 km/Hr.

I am glad that you are not in charge of the maintenance dept of Qantas !!

JC

 

Manufacturers often use rental car and other fleet government agencies as testbeds for maintenance requirements. They use methodology I support backed by rigorous statistical data points for reference. Fleet's only change stuff when statistical evidence supports the finding since 500 oil changes is a lot more expensive than just 1.

We all do this. Isn't using 50% of your engine oils's life a waste?

Let me clarify earlier. I do not second guess manufacturer requirements, simply that they err on the conservative for a wide safety and liability margin and to avoid tarnishing brand image. Furthermore a standard vented disc brake is very unlikely to shatter at speed, maybe if cross drilled. It is more likely to increase breaking distances and warp due to decreased material and heat dissipation issues.

Tires have notches in the grooves to signify EOL and going beyond that point results in decreased performance. I generally get the best A/S or summer tires available (currently running Michelin Pilot Sport A/S Plus) and replace them often since i've found that 10ft can be the difference between crunching in the front end or walking away with a little burnt rubber.

Manufacturers have a boatload of testing data on engine oil performance but generally treat it as proprietary data. However, there recommended intervals are arrived at through rigorous analysis and extrapolated to general population size. All the while, I am searching for published manufacturer data on minimum acceptable wear characteristics for engine oil. I'd love to be able to compare Blackstone results with officially blessed Mercedes-Benz tech docs.

Aeroplanes by nature are subject to much higher safety margins and furthermore, rigorously inspected, and regulated by agencies such as FAA.

 

Rev to liv, I am sure Glyn will chime in here shortly. But, follow the link in my signature for my oil analysis thread where Glyn and a few other knowledgeable members discuss the results.

I frequent BOG forum, and all UOA I have seen on there, and my own results show Mobil 1 shears to a 30W fairly quickly and has higher that average iron numbers compared to other oils. I am in no way saying it is bad. But, in my experience with my M272, it holds up just fine to 13K, but much beyond that is questionable.

 

Thank you Johand. I skimmed through your thread mainly because your Blackstone results are marked by a "?"

 

I'm not going to go into any kind of detail here because it is not worth it for a passenger car & with present sump capacities & filtration practice, there are service drivers other than oil change. I have always considered US 13K mile/20K Km's change to be reasonably proven to be at about the max sensible limit. The fact that MBUSA has moved the W204 to 10K miles change intervals on the M272 tends to support this. ROW has always been at 15K Km's or 9.3K miles.

The oil company that I come from does indeed publish a full set of condemning limits for lubricants used in every imaginable application for internal use by its field engineers called the In Service Oil Monitor. I am not at liberty to publish it. Someone like Blackstone might be prepared to let go their elemental condemning limits vs. mileage for engine oils. You could always ask. The problem with doing this is that some human intervention is required to interpret what is going on & inadequate knowledge can be a dangerous thing.

Now - If I was running the full Total Fluid Monitoring & Management, Condition Monitoring & Predictive Maintenance Plan for Newmont Mining (copper/gold) in Indonesia that has the largest fleet of Caterpillar equipment on any site in the world, generates it's own power with 16 Wärtsilä engines bigger than your house & it's own coal fired power station, all support equipment right down to 2 glycol recycling units for coolant etc. I would think differently. We have an on site lab there & run the whole integrated system for them right down to vibration monitoring, ferrography etc etc.

In this situation everything is constantly monitored & optimum change intervals for all equipment is established for each & every unit & compartment. Then other service requirements are overlaid upon that to manage servicing which is done in the pit by service vehicles & teams to minimise downtime. I could go on but won't.

You can do this for your car if you wish. I warn that once you start you can't stop or the whole effort is a waste of time. This is predictive maintenance. For one unit it gets costly & I'll bet you will get tired of it. The best you can do is develop a trend over numerous engine oil samples to establish a drain interval for your specific operating conditions. You will just have a good statistically valid trend when time comes to sell the car.

More practical to listen to Benz.

 

Rev 2 Liv ,

It's is a free world & it has been an interesting discusion.

Enjoy your data collection & post the results.I will be interested.

Just make sure it has no ill effects on your Benz.

JC.

 

JC - the problem is the amount of time & mileage you require to put on to develop the data. Even if you had the car on a dyno 24/7 running a European urban cycle or whatever it's going to take a long while. Then you need a control vehicle to run along side. The oil companies & the OEM's have done the miles. Doing additive top up is not the answer either. You need to get the contaminants that are in suspension in the oil out of the engine by draining or you start catalysing oxidation etc. This will ultimately lead to polymerisation & a sump full of goo.

 

I agree Glyn. I have spent a few bucks on oil changes/filters over my motoring life & the policy has served me well.

I have had Peugeots for over 30 years & do not know what their pistons look like. The old 1884 Honda XL 185 farm bike sitting under the tree in the backyard has its oil changed every 6 months & still has the original pistons & rings.Same with lawn mowers & pump engines, it has never been pistons/rings ,bore or bearings that have let them down.

You know , it is pretty difficult to wear out a well made engine if it is maintained correctly with regular oil & air cleaner /filter changes .Usually it is what they are driving that gives up first!!

All the best,

JC