[chiefneil]

I've always driven my new cars normally during break-in period, except I avoid running them up to redline. I don't drive like a maniac generally, so this typically means rpm's between 1500 - 4000. None of my cars have ever burned significant oil, and I'm on my 5th BMW now. We typically keep them 8-10 years, 80-120k miles.

I was doing some googling on the the subject and found some interesting discussions on aircraft sites. I don't know if it's directly applicable, but on the aircraft sites they say that too low/slow of a break-in (extended operation at low rpm) can cause the rings to anneal. That reduces their ability to transfer heat and can lead to glazing of the cylinder walls. Too fast of a break in (extended operation at high rpms) can cause spalling. So in general I'd say that supports BMW's general recommendation to vary rpm with moderation.

But all of that said, while I find it to be of academic interest I think that's all it is. The sheer quantity of opinions and anecdotes leads me to believe that probably none of it matters a bit. Drive it like you normally would and you'll probably be fine. Because no matter whether you drive it fast, slow, or somewhere in-between, thousands of people stand ready to say they do the exact same thing and it works perfectly for them.

[BEAR-AvHistory]

Same old same old. Instructions from the guys who actually built the car based on testing, examining failures etc & the opinions of non technically trained forum guys 99% who have never built an engine or trans in their lives.

Its not just the engine that is being broken in but every moving part on the car down to the tires.

Race engines are run like you stole them but they are assembled differently & are torn down for rebuild on a regular schedule.

[Kafkaesque328]

Modern cars are durable. If you drive it like you stole it at mile 1, I think it would take a decade or more for any negative effects as a result of that to surface, if ever. I wouldn't worry about it but I know some guys swear by the break-in thing, just like they swear by 5k oil changes on moderns cars that can do 10k mile intervals on synthetic no problem. I've never followed any break-in but I don't keep cars long enough to know one way or another. Some guys are somehow certain that they will keep their car for 10+ years when they get it and get all precious with it in the beginning, and more power to them for it, but life it too short to wait well over a month to go WOT on my new BMW. Not going to happen.

What I find interesting is that some of these same guys will talk about the virtues and inherent "value" in buying a car CPO, in which case, you have no idea if the original owner followed factory break in recommendations. Most CPO's are lease returns and I highly doubt people leasing follow a break in period. I know I didn't, nor will I ever. My car only has 6500 miles on it but I drove it hard from day 1. Way too early for any problems to arise but so far so good. My wife's Tiguan we got new and it's about 2 years old and I drove it like a maniac from day 1. Never been in the shop. Maybe in 10 years, but why on earth would I still want to have my wife's '13 Tiguan in 10 years? So, if you care about or believe in factory break in recommendations, don't ever buy a used or CPO car. Buy it new, baby it for a while and then enjoy.

Originally Posted by BEAR-AvHistory

Same old same old. Instructions from the guys who actually built the car based on testing, examining failures etc & the opinions of non technically trained forum guys 99% who have never built an engine or trans in their lives.

Its not just the engine that is being broken in but every moving part on the car down to the tires.

Race engines are run like you stole them but they are assembled differently & are torn down for rebuild on a regular schedule.

Agreed

[buckybadger]

Seriously guys, are we living in the 70s and 80s...

Just drive the car normally and you should be fine.

[zksi]

Originally Posted by chrisny

+1

I've been hearing for years that it isn't necessary anymore but lots of posters on here seem to think it is.

Actually the break in is still advised by reputable dealers, my salesman told me in detail how to follow this procedure, basically for best performance and life drive moderately up to 1500 miles and vary your rpms up to 4000 rpm for petrol and 3000 for diesel. Even if doesn't need any break in the new oil inside needs at least 500 miles to properly settle down in the engine and maximise its lubrication.

[e46M3-19010]

I wandered here looking for an answer to a different question, but I was so taken by what @BMWrules7 and @BMRGUY had written that I wanted to speak up despite the post now being old.

I’ve spent many hours researching and discussing break-in issues with engineers at aviation engine manufacturers, and what they shared largely lines up with the advice from @BMWrules7 and @BMRGUY. Given the cost and attention to detail concerning aircraft engine performance, and reliability, I’m inclined to follow their lead.

Having used their approach with a number of BMWs, and some other pretty high performance vehicles, I’ve enjoyed virtually no engine issues, and very low oil consumption, despite those cars being, er... well exercised.

BMW’s roots in building aviation engines has no doubt contributed to their remarkable record of one great power plant after another. ///

[eluded]

Originally Posted by ric124

I like the factory recommendation of keeping it below 100MPH for first 1200 miles.

[Mauricio Palacios. MD]

I found this, very interesting and useful...

http://www.avweb.com/news/maint/1849...l?redirected=1

[paul e]

Well, I broke in the last new car I drove according to the manufacturer, VW. That car, a 1999 Passat V6 5MT, is still sitting in my driveway, waiting for my brother to pick it up next week and drive it back to Baton Rouge.
It has never given me a lick of problems, other than the well known cam seal plug oil leak.

I have been driving the new 340i according to to the break in schedule. I still accelerate but I just don't let it wind past 4500 rpm.

Kinda funny - the car was due to come in right before my holiday trip back to CT (from SC). I told them I didn't want to pick it up before because I didn't want to put 2,000 highway miles on it from the get go. They agreed - what can they do? - but I got the impression they thought I was nuts.

Anyway, no real issue keeping it under 4500 for 1200 miles. Still lots of power.

[Louda0801]

Originally Posted by ric124

Here is the best advice you can get and I wouldnt trust anyone else!

Read and follow what the manual says, it is made by the same people who made the engine.

What about a diesel? Not picked mine up yet so can't read the manual.

[floydarogers]

Originally Posted by Louda0801

What about a diesel? Not picked mine up yet so can't read the manual.

Download a manual from bmwusa.com

Only difference is 93 mph and 3500 rpm limits.

[catskillclimber]

Originally Posted by Louda0801

What about a diesel? Not picked mine up yet so can't read the manual.

We have 45k on our 328D and it doesn't burn or leak a drop of oil. If I remember correctly I varied the rpm for the first hour, mainly between 1500-3000rpm, with couple short spikes to 4000rpm. Higher rpm's after engine oil reached normal op temp. I considered that we were also breaking in the transmission and differentials so I gave it a cooldown period after 20min and again at 40min, probably 20-30min each time.
Any diesel tractor or other heavy equipment engine manual as well as diesel engine rebuilders will tell you to load the engine from the get go, usually around 75%.

[TripleVANOS]

Originally Posted by rohms3

Did you lease or buy?

I leased my car, WOT right out of the dealer lot, and beat the crap out of it the remaining 1000 first miles. It's somebody elses problem when I'm done with it

Jesus, that's a terrifying statement. While what you said is factually accurate, it's very sad to hear coming from a fellow BMW owner.

I was brought up to treat my belongings with care and respect, and to treat other's things with the same level of respect as I would my own.

It is neither difficult nor inconvenient to simply 'take it easy' on a new car for a short period of time while the engine is still new.


I hope you change your thinking on this.

[robbiep]

Originally Posted by ric124

Here is the best advice you can get and I wouldnt trust anyone else!

Read and follow what the manual says, it is made by the same people who made the engine.

Basically, try to follow that as much as possible. If you go a fraction over the suggested rev number, it's not going to fall apart.

But stop over-thinking it. The phrase to try to follow is 'mechanical sympathy'.

Trying not to drive like you got daddy's car and you want to show off, because you've finally hit puberty - that sort of thing.

[STR8-6IX]

engine break in period is 3000 miles

avoid revving past 3-400RPM for this period

no aggressive or stupid shifting

easy on the tires, brakes suspension. be smooth and linear with your input

clutch break in period is roughly 1000 miles. no aggressive clutch work

tires and brakes-500 miles

transmission break in takes a long time. I would avoid aggressively launching for roughly 10-20000miles

[Kennybar112]

Picked up my 340 yesterday & the dealer told me 2-3k mile break in... seems excessive so ill prob be matting it after 1.5

[Revelator]

Apologies in advance if this is a dumb question, but is there any kind of break-in period for the audio system (i.e., should I not crank the speakers right away)? I'm a firm believer in the engine break in period, but one thing I do tend to do is test the sound system out almost right away as I'm taking my first ride home. All joking aside, would care to know to those in the know!

[mbferrari]

After reading this entire thread, and following the OM, I am doing this with mine....currently at 100 miles:

- Going to vary RPM and not run Cruise Control until after around 1500 miles for any length of time.
- Will keep the RPM below 4500 yet drive it up to that point sturdily once the motor has warmed up.
- Will change the oil and filter to Mobil 1 Syn at around 2k miles

Other than that I am just going to drive it like an adult. If this isn't enough then BMW has bigger problems with their B46 motors and cars.

Then, after 3k miles I am going to the dealer to put in a Dinan upgrade and then once it is warmed up I will "try the limits" and see what it can do...

Will report back and let you all know how it turns out.