BetterMakeWay

The thing is that i'm more than confused with what some say. Some say AND more important have proof that their car pulls like hell (some even got higher hp specs from the dyno than factory specs) because they broke in their car by redlining it very fast and reaching top speeds in the meere few km of the car. There is even a theory wich most of you know about...that says the piston rings seal up in the best manner if the engine is subjected to this kind of treatment...and way better if it had been broken in as the manual says.
Others do the exact opposite, follow the manual and well...live happly ever after, no drama no fuss and no big deal.
Some say that nooo if you brake the engine in like that (hard) the engine will eventually start to drink alot of oil (half a liter every 1000-2000km) but i've seen such complaints from guys that broke in the car the "proper" way. Especially in high revy petrol engines like the M engines.

So bottom line what do people think? I'm asking since i'll probably run to a petrol bmw engine in the future and i'm still confused on how to treat it.

PS: I do fear for the....conservative members of the forum...but i don't want to expect anything.

Ricracing

Do not be stupid!

All engines need to be braked in!

And not only the engines, tranmission, clutches, brakes, tyres...


I.e. do you think that any race engine is not test drived in the bench?

BetterMakeWay

So is every engine from bmw. All our engines were broken-in first on the test bench. The same probably for the tranny. I dunno if together but you'll say now that they have to be broken into syncronisation as a total and complete unit. Probably right.
Also brakes are "broken-in" by bmw or dealer...when they avoid ovalization or smth like that.
Tyres yes...200km of brake-in....come on...

mullman

During Euro-Delivery I hit 140mph once, but otherwise I kept it under 4500 rpms cruising around 125 mph.

As someone who rebuilds vintage BMW motorcycle engines I come from a different perspective - I am more worried about the brakes and tires in the first few hundred miles (being able to stop) then the engine. Modern machining techniques and materials make a really tight engine off the bench.


So I guess my bottom line is somewhere between drive it like you stole it & baby it.

BTW, at Dingolfing (birthplace of 5er, 6er, & 7er) I saw techs rev and spin the tires of brand new cars off the line. Before you even get your new baby, it has all been done.

Bimmer32

Funny, my first posting on this forum was about this very same topic of engine break-ins. My take on this is that if you want a fast engine (strictly engine), you drive it like you stole it. Redline it in every gear for piston sealing purposes. It may not guarantee the longevity of your engine, but you'll get a fast engine. If you follow the manual, you may get a long lasting engine (strictly engine speaking), but not a fast one. The manual is there for legal purposes and to protect BMW warranty period. If anyone wants to prove me wrong, back up your claims with some racing engine or rebuilt experiences. Personally, I chose the mix break-ins.

BetterMakeWay

So that answers it...

needforspeed

I don't think the run-in period is all about the engine.

New tyres don't grip well initially and new brakes don't stop well - in theory each need to be 'run-in' for up to 500 miles.

Likewise other new components don't really benefit from being subjected to immediate hard use.

But ... when it comes to the engine - you have a lot of moving parts that haven't moved much before and oil that needs to find it's way to every nook and cranny .... so it's best to be a little bit restrained in case something isn't exactly as it should be.

(better to have a minor mechanical failure at low revs than the redline)

Having said this ... if you don't follow the manual exactly nothing is going to explode and your car will not be knackered at 10,000 miles.

With my new car I will be following the manual (mainly) but won't feel bad if I can't resist a little bit of hooligan behaviour.

Once you are out the run-in period - BMW's like to be DRIVEN - HARD.

UUronL

Well, allow me to offer up my experience.


I followed the manual to the letter (as I have for the past 2 german cars I purchased). My car was one of the first N52 inline 6 (petrol) engines, made in March 05 and delivered in April 05. Many many many cars that were manufactured at the same time and delivered to members on this forum required numerous additions of oil, some very early in their life.

My car has only dipped down one line on the oil gauge, and this only happened at the 1 yr. mark - about the time that oil begins to break down a bit. I think lack of oil consumption is a great indicator of the general quality of the break-in and how everything seated. Mine has done far better than most, which could be accounted for by plain old luck (getting a "well built" one), but I imagine it has more to do with how I have treated it.

BetterMakeWay

I understand u, and i really think that it is true what you say. The more carefull you are with it the less oil is going to drink. But my original question is...do you think the engine will give out better performance figures if it's broken-in hard? Cuz if this is the case then i'm willing to sacrifice some liters a year of oil for better performances...especially if it's an M engine.

You know there is another tale: the one that i think it's rather true. That if a new car gets on the hands of a woman or an old man or anybody that would generally drive slowish then after a few thousand miles...maybe 10k you could easily tell the difference between that car's potential (that pretty much hasn't seen the red line or the high-end half of the rev range) and a similar car that has been driven pretty much hard since day one.

needforspeed

I can't see how this can be true. An engine / drivetrain needs to loosen up before you get peak performance and I suppose if someone really babied a BMW it might never loosen up (I have had BMW's where the gearbox still felt excessively 'tight' at 40,000 miles - even after my driving).

The running in period is more about letting all the complex components throughout the car settle in. That's why I will be trying to behave during the first 1,000 miles or so - then pushing on.

With anything mechanical - it either fails early on - or after a couple of years or so. The run in period just lets you iron out any latent defects.