Vrodman

Hey Guys,

Just letting you all know that I just heard last Friday from my SA that a new bulletin just crossed his desk from Germany regarding new AMG engine break-in protocols. He knew I was working toward 500 miles and wanted to let me know. Apparently, the new guideline is the following:

During the first 1000 miles do not:

Exceed 4500 rpm
Exceed 85 mph

So far I have done neither of these. But UGH!! Now I have to wait until 1000 miles to open her up. Oh well, it's worth the wait for the new motor.

sunil517

I can understand the 4500 RPM limit but what does the speed of 85MPH reason.

Vrodman

Ah ! Very good question. I was wondering the same thing. So I did some thinking on it. May or may not be correct. But my best estimate is that when you are traveling at 85 mph the car is experiencing higher drag forces due to the wind. So while you are only at 2000 rpm or so, you are at that rpm with a higher torque on the motor. Basically I am saying that 2000 rpm at 45 mph has a moderately lower load on the engine than 2000 rpm at 85 mph. Make sense?

It is the only thing I could come up with.

Brendon Hudson

How detrimental is it to the motor if every once and a while (rarely) it goes above that threshold?

Vrodman

I am making a somewhat educated guess that it is not that detrimental for an occasional slip. I am doing my absolute best to not go over the 4500 as I agree with you this is likely the bigger concern of the two. but have I accidentally crept up to 90 for a moment once or twice so far? Yes. Momentarily. Out here in the Bay Area on some of our freeways (during non peak commute times) you will get run over under 80mph. And as everyone on this site knows, these cars can get to 90 from 80 quite fast and without much effort.

Bottom line is that I am trying to adhere perfectly to the factory break in guideline. If something happens to the motor later, I want the peace of mind knowing it was not because of how I broke it in.

Brendon Hudson

I know, me too. I am being super cautious about it, but I lose track of my speed/speedometer and I look down and I'm a bit over 90 and right at the 4800-500rpm mark. I floored it once, in the very beginning, just wanting to see/feel/hear the power but haven't since then.

PeterUbers

ygmn

It is all guess work for them.....

what is the science behind it?

To wear in the rings and bearings and catch any metal debris in oil filter....

PeterUbers

kponti

Note, if you buy used, chances are it was leased and chances are it was broken in at wot from the onset. This has been happening for decades now

Vrodman

I fully agree! However, since I have the opportunity to break it in correctly, I am going to. Also, improper break in doesn't necessarily translate to some type of engine failure. It might be that the improperly handled engine just goes through more oil than it should. Or maybe it's overall life is a bit shorter. OR, maybe nothing at all.

kponti

I have seen more properly broken engines burn oil than improperly broken in engines......

PeterUbers

Vrodman

So let me ask you this:

If you were just given a brand new motor, would you be jumping on it from beginning? Just curious. Also, after I get to the 1000 mile mark and start having fun, I will be monitoring oil consumption and I will indeed report back here for everyone interested.

chiromikey

ItalianJoe1

Drive it how you want it to run from day one. Change the oil at 500 miles and let it fly. This is what every serious engine builder I've ever spoken with uses.

The break in for these cars is more about letting the powertrain learn itself it, learn all the adaptation, etc. Nothing to do with the engine wear, more for the transmission and other smoothness factors. Same reason the break in is supposed to be done in Comfort mode, not sport or sport+ or whatever.

ItalianJoe1

Modern mass production engines are so well finished, they break in almost immediately. I am a believer in exposing the new rings to some pressure/vacuum, as in letting the rpms come up to say 5k and then coasting back down in gear, several times, to allow the rings to experience the full range of operating conditions while they are seating in. But this happens in a few miles, not thousands.

chiromikey

superswiss

Yeah, there are various opinions out there on this subject. There's the well known Motoman method, which advocates to run the engine hard. They claim that you only have about 200 miles to seat the piston rings properly. They have demonstrated it on motorcycle engines and have shown that an engine that was broken in hard has much less blow-by etc. Most advocate for at least varying the rpm and load. What you don't wanna do is going for a road trip right away and just cruise at constant speeds. Try to vary the speed, load and rpm. Drive it in manual mode for example, so you don't constantly hover around very low rpms. Like my current car, I'll be breaking in the C63 S in Germany. I'll probably take it quickly up to higher speeds or at least do some moderate to hard acceleration early on the Autobahn.

Adaption of the various systems is another thing to keep in mind. Especially if you have the driver assistance package. The various semi-autonomous systems actually have a learning phase from the factory before they start performing optimally. It's mentioned in the owner's manual. So I think things like not exceeding 140 kmh may have partly to do with the baselining of all these systems, including transmission etc.

Also, brakes need to be bedded and the tires need to be broken in. New tires need about 500 miles to wear off the lubricants from the mold, before they develop their full grip potential.

Vrodman

So Guys,

If I am hearing you correctly, because my engine ONLY was replaced, the adaptation stuff doesn't really apply as the rest of the drivetrain has about 34k miles on it? So the 85mph max doesn't apply? And now with ~450 miles on the new engine I can start ramping up on pushing it?

BTW, who knew you can get decent mileage out of these cars? lol I had never driven any of my 3 AMG's easy before. over the first 450 miles, since last odometer reset, I am getting a combined 14.8. In the 2011 M156, I was lucky to average 12.0. The previous M157 motor averaged 13.5. On freeway stretches alone it seems to be well over the 20 mark.

chiromikey

Vrodman

Mikey,

WOW! Those numbers are well above the sticker values for the car. How is this possible? In fairness with my numbers, My commute is only about 10 miles each way and it's about half city driving. So I am not really seeing much long haul data yet. But I think even if I set cruise to 65 for 50 miles on a flat road I won't see close to 29. Maybe 24 I'm guessing. Oh, BTW, I also default to S mode. So I imagine if I try for mileage in C mode it would be a bit better. However as easy as I have been driving her since the new motor went in I'm not sure that would matter alot considering that the S mode simply raises the shift points and starts out in 2nd gear.

But seriously, please explain how you can get these mileage numbers. I am clearly missing something if these are correct. And GREAT for you if they are!!

chiromikey

brfatal

Those are pretty normal break in procedures. Add into that no sudden acceleration or sustained RPMs (no steady highway jaunts) and you'll have what basically all manufacturers call for during break in.

exhaustgases

Break in has everything to do with wear in and mating. Even gear sets need to break in. Oh and most likely your "every serious engine builder" either lives in the wives tails world of engine break in, or has not had to deal with all aluminum cylinders. In the days of old when decent not so easily scratch able materials like iron were used you could get away with more.