[Driver72]

So you are using the new car dealers salesperson as the guide to what is best for breaking in a new car's engine?
I don't buy new cars unless they are truly NEW...meaning no one else has driven them. I won't buy a performance car with even 40 miles on the odometer. My BMW had 3 on the odometer and all the plastic and seat covers still attached.
Sorry but I'll take the advice of the mechanical engineers and the brilliant minds of the researchers and developers that make the engine over the dimwits that sell cars.
Not saying you need to abide by the break in procedure "by the book" or the engine is going to fall apart, it's just wise to at least TRY to stick to those procedures IF you care about the engine and so forth.

Funny how people have NO problem beating on a brand new engine but feel it's absolutely necessary to allow a cold engine to warm up a bit before beating on it??? Funny logic those people must have.

Manufacturers didn't go from "mandatory" 3K oil changes.
The only people that pushed for that are the oil companies.
Like DeBeers diamonds, the 3K oil change marketing was brilliant.
It made the oil companies even richer by making you feel you NEEDED to do this or your engine will not last.
Oil companies have deep pockets and the auto manufacturers probably "benefitted" from them by following their 3K oil change advice.

By the way, there are three primary reasons why you can go a lot longer between oil changes now than you did a decade or so ago.
1. More accurately computer speced and balanced engines that run cleaner and better. They don't "break down" as much. They just don't "pollute" as much and break down the oil as easily now.
2. Better quality oils and engine cleaners/lubricates in these oils as well as in the gasolines.
3. Synthetic oils


The auto manufactuers have NOTHING to gain by just making up a break in period for their engines/drivetrains.
They WANT you to do what's best for the engine and the longevity of the car. Seriously, they'd benefit MORE by NOT telling people to do it and IF the car breaks down more often (especially AFTER the warranty expires) they'd make more money in service, parts and labor...and people buying more new cars.
EVERY manufacturer HAS a recommended break in period for their cars....they also do for motorcycles.
Personally I can't think of a single motor driven engine/vehicle or piece of machinery that the maker does NOT recommend a break in for.

None of them say, "feel free to beat on it and run the hell out of her from day one, it'll be just fine and last for a really long time doing it that way."

But people will always feel they are smarter than the experts.
People also don't listen to their DOCTORS when they give them medical advice that could save their life or help them heal faster and better. They often just dismiss this advice and go do what they want to do anyway...regardless of the consequences.
I'm sure those people listen to the GNC nutrition store sales person as what's best for them too.

Oh well...to each their own.

Originally Posted by HyperM3

When was the last time you took a test drive on a new car and the salesperson said "keep it easy, she hasnt been broken in yet"?

Hardly ever, and you know that if they had, you would have gone to another dealership. Now multiply that test drive by 20+. I highly doubt that car was broken in "as specified". It was broken in as if every one of us was driving the car on a daily basis and it was already broken in.

Funny how you all are worried about this 1200 mile break in period but nobody thought anything a few years ago when manufacturers went from mandatory 3k mile oil changes to guestimating you needing one between 15-20k miles. Obvoiusly these engines can handle WAY more than you are worried about giving it.

[HyperM3]

Originally Posted by Driver72

So you are using the new car dealers salesperson as the guide to what is best for breaking in a new car's engine?

You completely misunderstood what I wrote then went on your own little rant from there. I hope at least you feel good about it, because it had nothing to do with what I meant.

[Corey]

Originally Posted by The Cleaner

There is no break in, What does everyone think the break is does anyway? URBAN MYTH nothing more.

Seats the rings maybe? Blow by is pretty cool I guess.

[DrM]

"Seating the rings" was much more important in the past than today. In older engines (or poorly assembled ones) the cylinder is distorted when the head is bolted down. This means that the rings and the cylinder aren't the same shape and don't perfectly match. The process of "seating the rings" is caused by the rings and the cylinder wall wearing to fit one another.

In a properly functioning engine, the rings don't actually touch the cylinder wall anyway. They ride on a tiny film of oil. If the rings actually touched the cylinder wall, you would rapidly have a failure.

In modern engines, which are honed with torque plates, this process happens much less because the cylinder and the rings are much closer to the same shape. In theory, they would both be round.

However, I disagree that the "break in period" is an urban myth. All new mechanical parts experience a period of rapid wear in the beginning until the parts mesh properly with one another. Even in a well built motor, the rings will wear to fit the cylinder slightly in the beginning. I would, however, say that the need for break in periods is reduced given modern production techniques with greatly reduced manufacturing tolerances.

[natmad]

Ok, I will do it my way when I get my first BMW. I want a 335 sedan.
My way with my last naked sportbike was found in an article I read on breaking in race engines. Seems to me that the results I want for a street engine would be the same as a race engine. That is, I want it to last as long as possible and make the most power possible.
Basically, the article stated that multiple heat cylcles were used to break in the engine by running the engine up to full operating temperature and then allowing the engine to fully cool to ambient temperature before starting the next cycle. Each succesive cycle would see the engine operate under increasing load and reaching higher RPM's. Start out at low loads and rpm's to let all the parts get friendly, then moderate loads and rpm's to get these friends a little closer. After several cylces (7-10?) the engine has worked its way to the its highest loads (full throttle) and its highest RPM's (redline).
Now the parts are working together as a whole with close tolerances. Time to drive like a BMW is meant to drive.
High loads or high rpms early in the process are probably not beneficial to longevity or power output. Seems quite logical. I put about 50 miles or so on the bike during each cycle on city and country roads generally increasing the loads and rpm's each cycle. Ten days and @ 500 miles later I was done and my engine was well broken in.

[Black Chili]

Break-in was more relevent years ago; a lot with the cylinders mentioned above; the cylinders were (and still are) honed; some wear occured and help seat the rings with the cylinder much like 2 pieces rubbed together eventually produce a perfect fit. Not too long ago, you couldn't use synthetic oil in some engines for the first several thousand miles or the rings wouldn't seat properly and you'd end up with horrible oil consumption as the synthetic was TOO slippery to provide the necessary initial wear.

Today with synthetic oils, I've seen engines with well in excess of 100,000 miles with the factory cross-hatch cylinder hone still clearly evident.

Manufactures set break-in proceedures to a) get the most out of your car and b) (most importantly) avoid repairs for well past the warranty period. However IMHO, they tend to be overly conservative and designed for worst-case. I take it relatively easy for the first few hundred miles; change the oil to get rid of manufacturing left overs and assembly lube, then beat the hell out of it. You WILL see power increases as the parts fit together better and internal drag is reduced. Usually a lot at first, then less often then it doesn't happen at all after 30,000 miles (who knows with the 335 tho).

New brake pads should be bedded on a fresh rotor; some pads embed compounds into the rotor face which helps with friction and some pads can release gas which makes them less effective if not bedded properly, but not sure if that applys to factory pads.. regardless they'll still work fine, just not PERFECTLY fine if you're anal about those things, and that applies mostly to after market pads.

Warming up your car- not so good. Taking it a little easy when it's stone cold, much better. More clearence when the engine is cold and some tend to run richer before they warm up; bad for oil contamination as it tends to soak with gasoline a lot faster. Very bad idea to pull out of the driveway on a cold morning and run it straight to redline; fluids don't flow as well, parts aren't as well fitted as when worm and stress on the engine is already higher than normal.

Cars are designed to drop the clutch at 5,000 RPM on there way out the showroom door; the downside is that at 50,000 miles or above, you could find yourself with a slightly noiser drivetrain, worse than normal oil consumption and other problems because you didn't let the new car go through a few thermal cycles to get everything aquanted..

just my .02c

[razormy]

Originally Posted by JephryB

Break-in was more relevent years ago; a lot with the cylinders mentioned above; the cylinders were (and still are) honed; some wear occured and help seat the rings with the cylinder much like 2 pieces rubbed together eventually produce a perfect fit. Not too long ago, you couldn't use synthetic oil in some engines for the first several thousand miles or the rings wouldn't seat properly and you'd end up with horrible oil consumption as the synthetic was TOO slippery to provide the necessary initial wear.

Today with synthetic oils, I've seen engines with well in excess of 100,000 miles with the factory cross-hatch cylinder hone still clearly evident.

Manufactures set break-in proceedures to a) get the most out of your car and b) (most importantly) avoid repairs for well past the warranty period. However IMHO, they tend to be overly conservative and designed for worst-case. I take it relatively easy for the first few hundred miles; change the oil to get rid of manufacturing left overs and assembly lube, then beat the hell out of it. You WILL see power increases as the parts fit together better and internal drag is reduced. Usually a lot at first, then less often then it doesn't happen at all after 30,000 miles (who knows with the 335 tho).

New brake pads should be bedded on a fresh rotor; some pads embed compounds into the rotor face which helps with friction and some pads can release gas which makes them less effective if not bedded properly, but not sure if that applys to factory pads.. regardless they'll still work fine, just not PERFECTLY fine if you're anal about those things, and that applies mostly to after market pads.

Warming up your car- not so good. Taking it a little easy when it's stone cold, much better. More clearence when the engine is cold and some tend to run richer before they warm up; bad for oil contamination as it tends to soak with gasoline a lot faster. Very bad idea to pull out of the driveway on a cold morning and run it straight to redline; fluids don't flow as well, parts aren't as well fitted as when worm and stress on the engine is already higher than normal.

Cars are designed to drop the clutch at 5,000 RPM on there way out the showroom door; the downside is that at 50,000 miles or above, you could find yourself with a slightly noiser drivetrain, worse than normal oil consumption and other problems because you didn't let the new car go through a few thermal cycles to get everything aquanted..

just my .02c

well said.

[CoralRedPlz]

do people have differing opinions on how to break in the M cars as well? or do they still strongly recommend the 1200 mile thing for those?