Just picked up my Brand new custom made 2018 GLC300 4matic. Do I need to make sure I don’t drive over 80 km until at least I’ve driven the car over 100 km? Has anyone ever heard of this? or is that old school?

 

Your manual should state what you need to do. I've not come across what you stated. I think keeping it below 4000 rpm & 85 mph, avoiding S+, varying your revs for the 1st 1 K miles should be fine...

 

Here is a screen shot of the manual P.130

 

We broke ours in the way we were going to drive it. No problems at all.

 

Thank you very much everyone this is really helpful. 1K just sounds a lot. Trying not to rev too high is also very hard for me. I just want to zoom it.

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You own it - frankly be respectful in the 1st 1000 miles - you don't need to be wimpy - but on "redline" and "manual downshifts" be respectful - that's all you need to do..

 

exactly the same thing I did. Took it to the autobahn almost right after picking it up

 

Many/most of these cars that are purchased off the dealers lot have been test driven.....and you can rest assured that whoever took the car for a scoot did NOT read the break-in procedure from the manual. ;-) not really a big deal.

2 cents,
Dave

 

That's why I like to order my vehicles. Picked ours up with 7 miles on the odometer.

 

I'm not that patient. ;-)

Dave

 

+1

 

7 miles = 2 laps of the local track!!

 

I can't find any info on how many miles MB test drives a vehicle after it is built (after it comes off the line). I would think it would be a few miles. Then you have mileage to get it on and off the ship, to the dealer, and the dealer test driving before the sale.

 

It always surprises me how folks can decide they know more than the technical folks that design products for the rest of us. The break-in for a new car is based on getting you the best overall performance in terms of longevity, reliability and economy. A properly broken-in MB will get you 200,000+ miles with no more than routine maintenance and there are many examples out there to prove it. The other side of it is how many people in the US care it the vehicle blows an engine a week after they turn it in off lease?? So the reality is that if you don't plan on keeping the vehicle more than say 100,000 miles, break-in is probably a non-issue.

 

sorry still don’t know how to make pix smaller

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It's a non-issue in any case....it isn't 1965 anymore. Do what you like with your car but break in isn't the issue it used to be in years past due to far better machining and tighter tolerances in modern engines. I would advise on varying the rpm and avoiding redlne and sustained high rpm for the first few hundred miles.....anything more than that is overkill IMO.....but it certainly won't hurt to baby it longer which is why many manufacturer's recommend it: no downside. If you want your engine to last longer, I'd suggest on an early oil change (500 - 1000 miles) over worrying as much about how to drive it.

Here's a short read on the subject:

Modern versus older break-in regimens

For many kinds of equipment (with automotive engines being the prime example), the time it takes to complete break-in procedures has decreased significantly from a number of days to a few hours, for several reasons.

The main reason is that the factories in which they are produced are now capable of better machining and assembly. For example, it is easier to hold tighter tolerances now, and the average surface finish of a new cylinder wall has improved. Manufacturers decades ago were capable of such accuracy and precision, but not with as low a unit cost or with as much ease. Therefore, the average engine made today resembles, in some technical respects, the top-end custom work of back then.[5] For some equipment, break-in is now done at the factory, obviating end-user break-in. This is advantageous for several reasons. It is a selling point with customers who don't want to have to worry about break-in and want full performance "right out of the box". And it also aligns with the fact that compliance rates are always uncertain in the hands of end users. As with medical compliance or regulatory compliance, an authority can give all the instructions it wants, but there is no guarantee that the end user will follow them.

The other reason for shorter break-in regimens today is that a greater amount of science has been applied to the understanding of break-in, and this has led to the realization that some of the old, long, painstaking break-in regimens were based on specious reasoning[[i]citation needed]. People developed elaborate theories on what was needed and why, and it was hard to sift the empirical evidence in trying to test or confirm the theories. Anecdotal evidence and confirmation bias definitely played at least some part. Today engineers can confidently advise users not to put too much stock in old theories of long, elaborate break-in regimens[[i]citation needed]. Some users will not give credence to the engineers and will stick to their own ideas anyway; but their careful break-in beliefs are still harmless and serve roughly like a placebo in allowing them to assure themselves that they've maximized the equipment's working lifespan through their due diligence.

Dave

 

+1! Also need to remember that the engine is not the only thing being "broken in".

 

I was told last week by my M-B dealer that there was no need to break in the new engine as it had been done at the factory, I also was always told that an engine running pure synthetic oil will not break-in due to the superior nature of the oil.

 

I did have contact with an R&D developer of Mercedes motor design asking a similar question. His answer: "All experiences we have show that an engine needs a few hours of running in procedure. But it still needs it, and not full throttle from the beginning. But, running in means the whole car and especially the whole powertrain. That’s what most of all people forget, they are only talking about the engine. The most important part today is the gearbox and transmission line, especially the differential. The tooth-to-tooth contact line needs some time for running in because there is no production technology available which guarantees a perfect surface. In order to prevent unusual noise given by small pitting and prevent bigger damage, it is absolute necessary to run in the drive line as mentioned in the manual. Speed of the engine is during this procedure less important than the load because that also means high load at those points."