[NoMods]

a manual will always be better than a steptronic...only thing that comes close is the DSG, SMG or the Ferrari.

[RPM90]

Originally Posted by agent0986

Nope, that was already factored in. Someone was complaining a week ago about BMW giving inaccurate speedometers so I went and tested it out. There's this sign post in my area which reads out your speed electronically and i put the cruise control at 65mph and passed by and the sign was flickering, it couldnt decide between 60mph/61mph so yeah that guy was right b/c thats a pretty noticeable error. COuld the faster acceleration times maybe have something to do with the latest software upgrade? more aggressive gearing perhaps?

Software won't/can't change gearing.

[RPM90]

Originally Posted by akhbhaat

So you know, your car and engine are briefly run to redline on a road test chassis dyno before it even leaves the factory.

There's some debate among engineers and mechanics regarding the true necessity of break-in with modern production tolerances. Some say that the manufacturer specified break-in period is more for the benefit of the driver (familiarization) than the mechanical implements of the car itself. Some have even said that the gentle break-in period is actually detrimental to the engine, as it doesn't allow the piston rings to seat well. Since our engines (BMW) are already run to redline before we get them, I doubt that's something we'd have to worry about. I'd think more about the clutch disc than anything else when it comes to breaking in a new car.

Here's one side of the debate for your reading pleasure:
http://www.mototuneusa.com/break_in_secrets.htm

That is exactly what I say and have said for years.
Except, I don't accept that a gentle break-in is detrimental.

Clutch, brakes, trans gears, and other parts that rotate and have mechanical connections to other parts also have a "break in" period.
Many people forget that part too.

Going to redline on a new engine is no big deal. Full throttle WFO to redline
is a bit harsh. But, hey you pays your dime and you takes your chances.

[RPM90]

Originally Posted by 3aficionado

I've read this and it seems to fit more for certain engines (racing motorbikes in particular) than a general rule for all engine types.

The thing that scared me about this guys suggestions was:
Give me a break.

He also noted, “There's a very small window of opportunity to get the rings to seal really well ... the first 20 miles !!”. If this guy is right the chances are the dyno at BMW and a couple miles off the lot are all we have to properly seal the rings.

I guess I'm one of those people who would rather error on the side of caution after spending $40K+ on a car. So the boring factory recommended break-in is for me.

Synthetic is not regarded as the best oil to use in initial break in as it is quite slick. Factory break in doesn't use the oil fill you get. Once "broke in" the oil is drained and factory fill is put in.

[RPM90]

Originally Posted by E90Fleet

1) Its for less than 2 minutes, and just to test the engine

2) I can tell you a local BMW Tuner I know very well has for years asked people questions about their cars before Dyno test and before engine stripping. Questions were about running in period, oil change period and oil usage by the engine.

For the E46 his 6 year results have conclusively shown that engines that are run-in by their owners on average have more power and use less oil than the ones pushed since day 1.

He says he hasnt seen any noticible differences on tolorances on engine that were stripped for upgrades between cars following bmw's oil service interval and those changing oil earlier.



Its still to early for E90 results

"Break in" is mostly done (can't give you a percentage) when the engine is fired up for the first time after it's assembled. I don't know the BMW procedure about the dyno, but it's possible that wasn't the first time the engine was fired up. Even if it was, that initial run, even if only for 2 minutes, did a LOT of work in mating the pistons to rings.
The customer gets the engine already "broke in" for all intents and purposes. The rest is to make sure that everything else is allowed to "marry" itself on the car before you go pushing it, especially tires, which may still have some manufacture "release" material on them that can be slippery.

[richlux]

If it doesn't need a break-in, then why does BMW tell you to do it? What would they have to gain by telling you to keep it below 4500 RPMs the first 1200 miles. I could understand this being a load of bull IF BMW had something to gain by us doing it, but since I can't see how this benefits them and not us, I'll let my pistons and rings settle in the recommended way.

Rich