[Gnosis]

Why must you vary the rpm during the break in period? I've read this many times before but I just can't figure out what it's good for.

I mean - if I just pull up on the highway and cruise along at 2500 rpm, shouldn't that be a very nice, clean and painless break in?

[F32Fleet]

http://www.mototuneusa.com/break_in_secrets.htm

[CC 330i]

Read the url above, but also I will explain briefly what I have heard.

Keeping a constant RPM, even a low RPM, does not subject the engine or its components to a range of load characteristics. If you drive at 2500 RPM for 1 whole day, your engine will be only be used to that load, as opposed to varying the RPM and load by accelerating and decelerating in gear to let the engine experience different load characteristics that will seat the rings and bearings better.

If you plan on only running your engine at 2500 RPM for its entire life, then you would be fine breaking it in that way, but I am hoping it will not ONLY see freeway duty!

Honestly, I think the benefits of break in vary, and are probably pretty marginal, but it every bit helps.

Tires are the same way. You should do as much around town driving that you can in the first 500 miles or so to maximize their life. It causes them to flex in different ways (since you are cornering more) than pure freeway driving does, and somehow this break in allows them to last longer.

If all that is not enough to persuade you, then just find a good twisty highway and go driving for a day, and that will be a really good break in drive, and you will be having fun at the same time.

I am going to hit 1250 miles today, and plan on varying the RPM for a while longer (occasionally doing a near red line run now and then).

[Gnosis]

Wow.... that WAS controversial!

What do you guys think of this? He seems like he knows what he's talking about, but picking up a brand new BMW and then warm it up and trash it seems.... well... like getting on the first date and then after 15 min drag her home and bring out the S&M gear...

Would you do this??? The BMW stuff i mean.....

[silverado]

I follow what the manual says. I figure they know something about the engines they build and how to get the most out of them

It never seizes to amaze me that there is even a question as to what OTHER break-in techniques to use. Why should anyone think that this dude with a website knows more than the world-renound engineers of BMW know?

[F32Fleet]

Originally Posted by Gnosis

Wow.... that WAS controversial!

What do you guys think of this? He seems like he knows what he's talking about, but picking up a brand new BMW and then warm it up and trash it seems.... well... like getting on the first date and then after 15 min drag her home and bring out the S&M gear...

Would you do this??? The BMW stuff i mean.....

keep in mind he's talking about motorcycle engines. Not sure if his technique works on auto engines. I posted the link to give u guys a different perspective.

[CC 330i]

I read this before (linked from the Audi forum).

I wouldn't follow the recommendations on the web site, but I don't claim to be an expert. There are elements to what he is saying that make sense to me, though. I did rev my engine pretty high in the first 500 miles (up to 6000 RPM or so) a few times under hard acceleration after it was fully warmed up. I didn't baby it, but I didn't flat out abuse it either. I did a few hard acceleration runs after it was fully warmed up, but not from a dead stop.

Part of the problem for me was my car had 60 miles on it when I got it.... So according to this article, I would have missed the opportunity to follow his advice according to his "first 20 miles" statement.

I try to follow BMW's recommendations because they are the ones that will honor the BMW warranty, not this guy. Also, I am breaking in for maximum engine life, not maximum engine power. They don't break in Formula 1 engines like passenger cars, but F1 engines only last for 2 races.

[F32Fleet]

Originally Posted by silverado

I follow what the manual says. I figure they know something about the engines they build and how to get the most out of them

It never seizes to amaze me that there is even a question as to what OTHER break-in techniques to use. Why should anyone think that this dude with a website knows more than the world-renound engineers of BMW know?

But just imagine if BMW posted the break-in procedure the link is talking about. Talk about lawsuit material.

[silverado]

I did a lot of hard driving, but staying within the manual's recommendations. That is, I never exceeded 4500 rpm, I didn't floor it and didn't exceed 100 mph. However, I did a lot of fast acceleration upto 4500 in every gear (upto 100 mph) by maybe pressing the gas peddal to up to a 1/3 or 1/2 the way in.

[CC 330i]

I even floored it once or twice, but don't tell anyone!

[Gnosis]

I try to follow BMW's recommendations because they are the ones that will honor the BMW warranty, not this guy.

Good point...

And yes - BMW should know what they are talking about.... They are after all the only car manufacture with "motor" in its name.

And maybe how you break it in doesn't matter at all in today's engines....

Ahhh... what to do.. what to do... maybe I'll take a middle of the road approach like you CC 330i. Don't trash it and don't baby it.... Should work....

[CC 330i]

Just spend a day driving on a fun twisty highway (not freeway) and the break-in will take care of itself. Try to keep it under 4500 RPM, but if you go higher a few times it won't ruin the engine. It's probably good for it after the first 300 miles or so (and the engine is warm). Most "bad" wear occurs when the engine is cold, especially when new, so depending on outside temps, a short period (30 secs) of idling and then real easy driving for the first 5 minutes or so is really the most important thing. Once the whole engine has had an opportunity to get to "operating temperature", it's ok to drive a little harder.

The problem with the 330i is that when you hit 4500 RPM, the engine starts making a LOT of power, and it's hard to shift in time. The next thing you know you are at 5500 RPM!

My wife cracked me up because she was driving one day and revving a little high for my comfort and I was yelling "SHIFT, SHIFT!" and she just laughed because she was having so much fun! I am glad she is an enthusiast!

I also try to let the engine "brake" itself from 4500 rpm once in a while, by lifting my foot off the gas on the freeway at speed in 3rd gear at 4500 RPM (for example), and let the car coast down to about 2500 RPM. It allows the engine to experience negative loading, which I have heard is also part of a good break in technique. This would be hard to do with a Steptronic unless you had it in "manual" mode.

[silverado]

Being someone who always tries to follow break-in procedures, I still have a question. Does anyone actually know of cases where there was evidence of bad breaking-in of an engine? What did you see or experience? Did it compare badly to other engines that were broken-in better?

[CC 330i]

One typical result of poor engine break-in can be high oil consumption. There are several things that can cause high oil consumption but bad break-in and abuse is one major cause. Basically oil is making its way past the rings and into the combustion chamber. This can foul the plugs and also cause a smoky exhaust.

Later in life, the engine will have problems.

[Gnosis]

Yeah - I think I'm starting to see the picture...

1. warm it up
2. drive it on some twisty road and the break in will take care of itself
3. don't rev too low (BMW manual)
4. don't rev too high (BMW manual)
5. don't be afraid to push it a bit (the manual says nothing about not using full throttle between 1500-4500 rpm - right?)
6. use some engine braking (this is part of my driving style but sure - I'll give it som extra engine braking treatment...)

Sounds like a plan....

[Armen52]

I don't think you're supposed to be generous with the full throttle up to 4500 rpm. I will be sticking to no more than 3/4ths.

[CC 330i]

Gnosis, sounds about like what I did. Good outline IMO.

Keep in mind, however, that I think the manual does say that you shouldn't use full throttle during break in (even up to 4500 RPM), but I can't remember for sure. Double check and use your best judgement. I did one time I think, but really, I don't think that one time is going to hurt too much...

[jhbodle]

Originally Posted by silverado

Being someone who always tries to follow break-in procedures, I still have a question. Does anyone actually know of cases where there was evidence of bad breaking-in of an engine? What did you see or experience? Did it compare badly to other engines that were broken-in better?

My mate's dad used to work for a Nissan dealership. A customer bought a new car from there and basically ignored the break in procedure. He took it straight into France and planted his foot to the floor and sped down to Italy as fast as the car would go. After 700 miles, the car's engine gave out. They had to send an engineer out to drive the car back home after the engine was changed.
I've always wondered if it was just a dodgy engine or whether the 700 miles of solid (almost) maximum speed was the true cause.

[Gnosis]

I think the manual does say that you shouldn't use full throttle during break in (even up to 4500 RPM)

Yeah - you're right. I downloaded the manual and checked. Thought that I'd found a way to obey both the controversial and the standard break in procedure... but now I'll just have to choose... damn... I'll probably push the loud pedal about 3/4 into the carpet.... I hope it has a thin carpet....

[Gnosis]

My mate's dad used to work for a Nissan dealership. A customer bought a new car from there and basically ignored the break in procedure. He took it straight into France and planted his foot to the floor and sped down to Italy as fast as the car would go. After 700 miles, the car's engine gave out. They had to send an engineer out to drive the car back home after the engine was changed.
I've always wondered if it was just a dodgy engine or whether the 700 miles of solid (almost) maximum speed was the true cause

Ouch...

[xspeedy]

The reason you vary speeds is the same reason you move an edge on a grinding wheel when sharpening it. If you hold the edge still, the part of the edge touching the wheel gets too much material removed and gets overly hot while the other parts get no sharpening.

When driven at a specific speed and load, certain parts of the engine see more wear than others. If you only drove at 55 on a flat highway for the entire break in period, only those spots associated that with condition would be worn in. You want to drive at varying speeds and conditions to distribute the wear across all the surfaces.

[voltron1011]

Originally Posted by CC 330i

I also try to let the engine "brake" itself from 4500 rpm once in a while, by lifting my foot off the gas on the freeway at speed in 3rd gear at 4500 RPM (for example), and let the car coast down to about 2500 RPM.

Yes, this is VERY important for the piston rings. Glad you mentioned it.