[TractionControlOff]

Originally Posted by sdhotwn

I used to hand build engines (for Mazda's) and did tuning on the side to feed my racing habits. I'm also a mechanical engineer, have been racing for 10 years, and did engine research as part of lab work for a semester. I'm NOT an expert, but i have a solid background.

The RPM limit they recommend isn't bad, and the first 500-1000 miles it is reasonable to follow that. Varied load really is important. Relatively high throttle opening with some boost helps seat and wear the rings in, and can help reduce oil consumption, when doing that though, it's important to have some decent long decel periods immediately after. That helps wash the walls and pull vaccum to get the oil and metal shavings off.

The main reason for the recommendation as they give it in the manuals is if anything is tight, or people bounce it off the rev limiter (or fuel cut) you can get wear patterns or friction buildup that is less than ideal. Modern engines are so damn well toleranced now that catastrophic failure is essentially unheard of. The lighter loads DO help seat anything that may be slightly out of alignment and allows some of the assembly fluids to work their way out.

Also, many bearings and seals don't fully lubricate out and wear in until they've had some revolutions on them, and can heat up excessively with too many rpm's (hence the recommendation). Giving time for them to "loosen" and lubricate at temperature is another reason for the low rpm's for XXX miles recommendation.

I typically try to go out to the twisty roads for the first 200 miles in one session with lots of moderate cornering and up and down decel with limited rpm's and periodic large throttle opening. Higher pressures with low (but at operating) temperature seats the rings best with the least risk in my opinion. So that's what I do. I'm also absolutely adamant about an oil change at 1k. If you saw how much metallic glitter comes out during that oil change you'd think you damaged something.

Thanks, that's great info! Why do you think the manufacturers don't recommend a 1k oil change anymore? Are they assuming that the oil filter will clean out enough of that junk?

[sdhotwn]

Originally Posted by TractionControlOff

Thanks, that's great info! Why do you think the manufacturers don't recommend a 1k oil change anymore? Are they assuming that the oil filter will clean out enough of that junk?

Probably some confidence in the oil filter. Engines generate shavings continuously, so that's not abnormal to have it in the oil to begin with. Add in the cost for the included oil change, customer disasstisfaction for some having to bring in such a new car etc, and the relatively low downside to the manufacturer (engine is not likely to be destroyed, so they'll never pay, so why recommend something that costs them money?) and there isn't much reason for them to do so. I'm sure engineers have run simulations etc on it and found that the issue is minimal enough for it to be run as such.

My mentality is, what's 100 odd bucks for the extra change in the cost of a 50+k dollar car. Very simple, reasonably cheap, and worth even the tiniest benefit to me.

[floydarogers]

Originally Posted by TractionControlOff

Thanks, that's great info! Why do you think the manufacturers don't recommend a 1k oil change anymore? Are they assuming that the oil filter will clean out enough of that junk?

Originally Posted by sdhotwn

Probably some confidence in the oil filter. Engines generate shavings continuously, so that's not abnormal to have it in the oil to begin with. ...

There's also been some research lately that indicates that most wear occurs in the first 1-2K miles of an oil change, then gets less as the additives coat the engine surfaces and provide protection from further wear.

[sdhotwn]

Originally Posted by floydarogers

There's also been some research lately that indicates that most wear occurs in the first 1-2K miles of an oil change, then gets less as the additives coat the engine surfaces and provide protection from further wear.

Interesting. I've not seen/heard that previously. Doesn't make a ton of sense to me intuitively, but doesn't mean it's not the case. I'd assume the additives are coated on the engine surfaces to begin with and changing the oil wouldn't make a difference, unless they'd been worn out/used up, in which case the last miles before an oil change would be just as bad.

If you ever want to go crazy learning too much about oil check out www.bobistheoilguy.com

[floydarogers]

Originally Posted by sdhotwn

...
If you ever want to go crazy learning too much about oil check out www.bobistheoilguy.com

Check this quote from BITOG: "Here is where Fe wear gets really interesting. What happens if we break down the data from mass population, and get into directed duration sub-groups? I pulled out samples within the UOAs and found the average Fe wear was thus:

UOA avg. Duration 3K 5K 7K 10K
Fe ppm / 1k miles 3.2 2.5 2.5 2.3
It is in fact true to say that when you change oil frequently the UOA will exhibit a higher Fe wear metal count. There are two reasonable explanations to this phenomenon of elevated wear metals shortly after an OCI; residual oil and tribo-chemical interaction. When you change oil, no matter how much you “drip-drip-drip” the oil into the catch basin, there is always a moderate amount left in the engine. Ryan Stark of Blackstone estimates up to 20% of the old oil remains, more or less, depending upon the unique traits of each piece of equipment. So, when you begin your new OCI, you really are not starting at zero ppm. Additionally, there is indication that wear is elevated after each OCI because of chemical reactions of fresh additive packages. This claim is supported via an SAE study done by Ford and Conoco (ref #1) that surmised this very phenomenon, and additionally refers to a former study of the same conclusion predating it."

It's in the middle of http://www.bobistheoilguy.com/used-o...hat-is-normal/
The subject is not settled by any means...

[sdhotwn]

Ha! Perfect! Very interesting result. I'll have to read back through a bunch of that again. Good to see a source supporting it too. Thanks!

[sdhotwn]

Interestingly, further down after that he explains that the metal analysis does not correspond to wear rate. Basically states that wear rate is unaffected until the oil is compromised in some fashion. Does comment that soot, etc are another matter as well.

Edit: Reading through the whole thing he kind of contradicts himself on the wear rate/metal content a few times. Basically says that it isn't statistically significant, but that it correlates. Essentially says, "It won't hurt the engine to change oil frequently, but definitely doesn't help/isn't better than longer intervals".

[Kevin M]

I can appreciate the varying opinions, and I somewhat recognize that what BMW claims for break in period may not be gospel.

With that said, I'd have a hard to agreeing to deviate very far off of BMWs recommendations. They are by far in the best position to render an opinion on how to break in one of their own engines, and have remained consistent over the years.

You could produce massive amounts of internet opinion, based on detailed studies and educated thoughts...I still wouldn't think that one of the worlds most recognized engine manufacturers has got it wrong.

Thats just my $0.02. I sell insurance for a living, so what do I know.

I'll take my leased 335, drive it somewhat easy for the first 1200 miles (which will go by in a few weeks), then its on.

Besides, our cars produce so much low end torque, you can still haul ass without stretching much above 4000 rpm.

[sdhotwn]

Originally Posted by Kevin M

I can appreciate the varying opinions, and I somewhat recognize that what BMW claims for break in period may not be gospel.

With that said, I'd have a hard to agreeing to deviate very far off of BMWs recommendations. They are by far in the best position to render an opinion on how to break in one of their own engines, and have remained consistent over the years.

You could produce massive amounts of internet opinion, based on detailed studies and educated thoughts...I still wouldn't think that one of the worlds most recognized engine manufacturers has got it wrong.

Thats just my $0.02. I sell insurance for a living, so what do I know.

I'll take my leased 335, drive it somewhat easy for the first 1200 miles (which will go by in a few weeks), then its on.

Besides, our cars produce so much low end torque, you can still haul ass without stretching much above 4000 rpm.

If you read the manual, and my recommendations, you'll see that they don't actually conflict (other than I comment about raising the rpm maybe earlier than the 1200).

[floydarogers]

Originally Posted by sdhotwn

Interestingly, further down after that he explains that the metal analysis does not correspond to wear rate. Basically states that wear rate is unaffected until the oil is compromised in some fashion. Does comment that soot, etc are another matter as well.

Edit: Reading through the whole thing he kind of contradicts himself on the wear rate/metal content a few times. Basically says that it isn't statistically significant, but that it correlates. Essentially says, "It won't hurt the engine to change oil frequently, but definitely doesn't help/isn't better than longer intervals".

IMO, it would be really interesting for BMW (and other manufacturers) to publish some of their data and reasoning for choosing OCIs. They *KNOW*, but they're not talking.

[rlmesq]

Originally Posted by Seangd

I no longer believe these modern cars need a real break-in period. I was instructed by an engine builder to drive it like I wanted it to perform. I did the same thing with my BMW motorcycle and my bike is faster than another friends bike - same exact model. I'm sold on the hard break-in.

When I bought a Yamaha R1 a few years ago, I took it to several trackdays in the first couple of months. Since it was brand new, I wasn't going to push that hard and decided the stock tires would be okay, so I didn't immediately slap on a set of DOT race tires.

When I took it to the dealership for the 600 mile warranty service, they turned it over to a tech who had just started working there and didn't know me. He took a look at the tires, which were shagged all the way out to the sidewall, and called over the service manager, saying, "WTF has this guy been doing with this thing?"

The service manager just chuckled and said, "Heh, heh, heh... Bob's been to the track."

[Fat Panda]

During my first test drive of the 435i xDrive, the BMW Genius that took me on the drive commented on how manual's instructions for break-in is to prevent new owners from crashing their car. His words are that the engine comes pre-broken-in during manufacturing, and I should drive my car aggressive once I get as the computer can create a more aggressive profile.

I was surprised as he basically went against BMW's instructions. However I do believe that the initial break-in of the engine would be done in their engine plant.

[Lost Horizon]

Originally Posted by Hydim

.... However I do believe that the initial break-in of the engine would be done in their engine plant.

I believe the first time the engine fires in anger is when it rolls off the line with the fluids added to the finished vehicle... no break in other than to see that the crank turns and nothing rattles ..

[sdhotwn]

Originally Posted by Lost Horizon

I believe the first time the engine fires in anger is when it rolls off the line with the fluids added to the finished vehicle... no break in other than to see that the crank turns and nothing rattles ..

Correct based on what they said when I toured the factory. They rotate it/verify it works is okay, but it really doesn't get run in earnest, and definitely not broken in. Videos of the factory process on youtube confirm that as well i think.

[m6pwr]

Originally Posted by utenigma

Seating the rings properly is the reason for a hard break in

http://www.ntnoa.org/enginebreakin.htm

This method says, "Use high quality, low viscosity oil (Valvoline 30 weight), no synthetics, too slippery. If synthetics are used during initial break in the rings are sure to glaze over." So, according to the experts, I guess all our talk about hard vs soft is irrelevant. All our motors are toast from the get-go.

The n55 and all BMW diesels are made in Austria. This site says each engine is run-up by electricity (no mass emissions to choke the townsfolk). This is for qc checks. Couldn't be to seat the rings since there is no internal combustion to press the rings against the cylinder walls. The site also says some engines are randomly selected and run at full power for an extended period. I think this is also for qc. Clearly BMW doesn't seem to think all its engines need a hard break-in. http://www.bmw-steyr.com/index.html.

What floydarogers said earlier about the poor antiwear protection of fresh oil is correct. This well-known study: http://papers.sae.org/2007-01-4133/. It helps to read the paper to get a full appreciation. Only $25 from SAE. Be the first on your block to get one. It all revolves around the time (about 3000 mi) it takes for the anti-wear additives to become fully functional. A lot of motor heads have a hard time accepting the findings - it's so counter intuitive - but it's proven chemistry. Eschew those early, unnecessary, and too frequent oil changes. Treasure and keep your aged oil. It's slick(er) and protects your engine better.

[Fat Panda]

We'll I be dammed. I always thought and expected that each engine would be throughly tested before being released into vehicle production. You would think they would run it up to leak check the engine, check the emissions, and engine performance/telemetry. I guess with modern technology, and high tolerances in manufacturing, testing is not as critical.

[sdhotwn]

Modern engines have great tolerances, and the engine block etc really is just an air pump. So measuring the torque to electrically rotate the engine, and measuring air pressure at intake and exhaust and ignition port will give you 95%+ on coverage I think.

[Fat Panda]

I youtube'd a video for the N20 build, and at the end it looks as if they test the engine.

Testing begins at the 3min 40sec mark. Not sure if they are doing it electrically or actually running it with fuel. It does appear that a robot attaches intake/exhaust manifold, as well as maybe fuel lines as I see flex hoses.

[Lost Horizon]

Originally Posted by Hydim

I youtube'd a video for the N20 build,... It does appear that a robot attaches intake/exhaust manifold, as well as maybe fuel lines as I see flex hoses.

Sounds more like Air Pressure as the driving force.. plus it only goes to around 1500 rpm for a few seconds, then back to 700.. the other gauge is reading oil pressure, so the high pressure hoses lines might be lubricating the engine channels so it can run ..

Regardless, that's not much of a test as there is no cooling taking place for jacket water, etc... plus based on the production line sequence, it doesn't have the fluids in it at that station yet, and there is no real start sequence, making it look more like air pressure driven....

[catskillclimber]

Originally Posted by Seangd

I'm choosing to NOT follow the BMW recommendation. I'm driving it like I stole it, from the day I got it. I've had too many friends of mine that did the same with their new German cars and the results have been amazing. They all seem to have "ringers". They're all faster than other cars of the same make and model. My friends 2009 335i ran 13.53 ET at San Antonio Raceway. Another buddy in his S4 ran 13.19!

I no longer believe these modern cars need a real break-in period. I was instructed by an engine builder to drive it like I wanted it to perform. I did the same thing with my BMW motorcycle and my bike is faster than another friends bike - same exact model. I'm sold on the hard break-in.

From BMW webISTA...
"The oil consumption should be measured after a distance of 7,500 km at the earliest, as the process of running in the engine will not have been essentially completed and the engine oil consumption stabilised until this distance has been covered."

[Pro]

Originally Posted by catskillclimber

From BMW webISTA...
"The oil consumption should be measured after a distance of 7,500 km at the earliest, as the process of running in the engine will not have been essentially completed and the engine oil consumption stabilised until this distance has been covered."

he already choose not to follow the manufacturers recommended guidelines... and here you are quoting bmw again

i believe this 7500km thing is because ppl keep bothering dealers about oil consumption and they got sick of entertaining us

[Lost Horizon]

Originally Posted by Pro

he already choose not to follow the manufacturers recommended guidelines... and here you are quoting bmw again

I can see his point tho... personally, I never bought into the Gravity thing even tho many professional physicists have suggested it would be prudent to do so. Other than a few broken bones, looks like I've been right all along.

I'd expand more on this, but it's a nice day and I think I'll head out under the shade of the coconut tree in the back yard. It's been a great growing year.. there must be at least 60 mature nuts on the tree..