[silverbmwz3]

I'm not sure I can figure out how to make this a poll, but how many of you with new cars observed the "running-in" advice in the owner's handbook and how many of you drove it like you stole it?

[NFS]

Originally Posted by silverbmwz3

I'm not sure I can figure out how to make this a poll, but how many of you with new cars observed the "running-in" advice in the owner's handbook and how many of you drove it like you stole it?

There are many threads about this so it may be worth searching a bit.

My own belief is that the break in period is for:

1. Mechanical break in of engine components
2. Protection since most mechanical failures occur straight away - or not at all.
3. Bedding in of consumables - tyres, brakes etc...

The 1st point isn't really an issue in modern vehicles. So personally I would drive carefully for the first 500 miles until the brakes and tyres were nicely worn in and then gradually increase the revs.

The manual says no redlining for 2000 miles - I pretty much ignored this.

[silverbmwz3]

So you had yours from new?

Tried searching for "running in" and didn't find too much...thought a fresh poll might be in order....

[spesrf25]

I followed the owner's manual.....It was painful, though....lol.

Keep in mind, you are also breaking in the engine, tranny, differential. I would follow the owner's manual. A lot of people only think of a "Break-in" as ONLY the engine, which is false. It consist of many parts of the car.

[dxb335d]

i woudlnt personally worry too much about this, think about demo cars, hammered from the off, they get sold on and last just aswell as other no demo cars

[NFS]

Originally Posted by silverbmwz3

So you had yours from new?

Tried searching for "running in" and didn't find too much...thought a fresh poll might be in order....

Yep brand new on the 1st Sept 06 - 6 miles on the clock

[spesrf25]

Search for "Break in"

[silverbmwz3]

Originally Posted by spesrf25

Search for "Break in"

Have you tried that? Lots of threads about kids getting M5's cancelled by their parents but nothing much to do with breaking a car in unless I'm looking incorrectly!

[spesrf25]

Try this link:

http://www.e90post.com/forums/search...archid=1513577

[silverbmwz3]

Many thanks.

[silverbmwz3]

Consensus seems to be some do, some don't - but I don't see many people screaming that their car fell apart/blew up/BMW threw out the warranty.

[mjh93sa]

Originally Posted by silverbmwz3

Consensus seems to be some do, some don't - but I don't see many people screaming that their car fell apart/blew up/BMW threw out the warranty.

errrr, not much of a consensus then

Whilst there are merits to bedding things in gently, BMW will have tested the engines to the extreme, which at the very least means thousands of cycles to ensure that if somebody does redline it from cold after every start it's going to make it though the warranty period. Overall it may have a shorter life, but depending on how long you keep the car it is probably never going to be a problem. Even then it's likely to be things like leaks and so on rather than catastrophic failure.

MCN did a test some time ago where they took two identical new bikes. They dyno'd both to ensure that they were putting out the same power and then ran them in. One was done to the manufacturers guidlines, and the other was caned. When they dyno'd them again the thrashed bike was making more power. I forget the actual figures, but it was beyond a statistical variation.

[matlough]

Just a quick thought,

Do you think they have a run-in period for F1, BTCC engines etc etc.?

[Dave_3]

Originally Posted by matlough

Just a quick thought,

Do you think they have a run-in period for F1, BTCC engines etc etc.?

And how long do you think they use an F1 engine before a rebuild ? Hours.

And I would guess that the BTCC engines are blueprinted to exact specs with the best settings within the rules.

Either way, both will be handbuilt. Neither are expected to run in stop-go traffic and go for thousands of miles, and last years.

I've personally rebuilt a lot of my old engines, and just don't buy this simplistic "Drive it like you stole it" philosophy that seems to be adopted by those youngsters (most of them with the "I lease, I don't give a damn") who search the most power.

You can certainly use a new engine and start to put load on it, but do it sensibly. Let everything warm up, and let engine parts bed and settle in sympathetically. Just think of it as a human warming up before exercise, warm up before going for it.

If, as these DILYSI guys state, BMWs are already run-in, how come so many people state that the engine loosens up with more miles on it (especially the 335D) ? What is happening there ??

I'd much rather have a smooth, long lasting engine, than one that has been thrashed since day 1.

D.

[ChrisMWard]

Originally Posted by Dave_3

And how long do you think they use an F1 engine before a rebuild ? Hours.

And I would guess that the BTCC engines are blueprinted to exact specs with the best settings within the rules.

Either way, both will be handbuilt. Neither are expected to run in stop-go traffic and go for thousands of miles, and last years.

I've personally rebuilt a lot of my old engines, and just don't buy this simplistic "Drive it like you stole it" philosophy that seems to be adopted by those youngsters (most of them with the "I lease, I don't give a damn") who search the most power.

You can certainly use a new engine and start to put load on it, but do it sensibly. Let everything warm up, and let engine parts bed and settle in sympathetically. Just think of it as a human warming up before exercise, warm up before going for it.

If, as these DILYSI guys state, BMWs are already run-in, how come so many people state that the engine loosens up with more miles on it (especially the 335D) ? What is happening there ??

I'd much rather have a smooth, long lasting engine, than one that has been thrashed since day 1.

D.

I've got to agree with you Dave. Even though modern machine tools and manufacturing tolerances are better than ever, metal surfaces rubbing against each other do need time to bed in.

Racing engines are completly different though. When I was involved we would under grind the cranks and overbore the cylinders to allow an engine that was built on Saturday to be run flat out on the Sunday. Twenty minutes of running in was about the limit. No way would it last thousands of miles though.

Regards

Chris

[m33porsche]

Originally Posted by matlough

Just a quick thought,

Do you think they have a run-in period for F1, BTCC engines etc etc.?

mat - nice thought - not sure how it helps though

[- Paul -]

I kind of followed the BMW recs but still thrashed it other times. As an engineer, I understand the merits of break-in but as someone already mentioned here, the manufacturing process is very precise now. Tolerance levels are a lot lower.

[AndyB]

My plan will be to try to stick to the book as much as possible but if I need to put the hammer down for any reason, so long as the car is up to temp, i won't be afraid to do so..

[rjs]

Originally Posted by AndyB

My plan will be to try to stick to the book as much as possible but if I need to put the hammer down for any reason, so long as the car is up to temp, i won't be afraid to do so..

Similar to me, I'm prob going to go a bit gentle for the first couple hundred whilst the brakes etc... bed in, then as long as the temp is up i won't mind giving it some stick.