break-in period

The factory recommended break-in time is actually 3000 miles. SOA says you can change it as early as 1,000 miles if you like. See below for the response I received:

"We recommend that you first change the oil in your 2004 WRX STi Sedan at 3,000 miles or 3 months, whichever comes first. We STRONGLY recommend that you at least wait until the break-in period of 1,000 miles is surpassed.

"The break-in period of the engine requires that a given amount of friction exists between components. The piston rings need to rub against the cylinder wall to break-in or finely tune the machine mating between the two metal parts. To properly seat all mechanical components, a certain amount of friction is required between the metal parts.

Thanks for the opportunity to be of assistance. If you need any future assistance, please feel free to contact us.

Best wishes,

John J. Mergen Subaru of America, Inc."

And I was told to not use the cruise control for the first 1000 miles. I would follow the manufactures recommendation of keeping it under

4000 RPM at least until 1000 to 1500 miles. Take it from me, you will have plenty of power even at 4000 rpm.

BlueSTi "Scary-Fast"

'THEY' (you know - 'they') say that at some rpms the rings might resonate causing some unusual wear pattern that could the lead to abnormal oil consumption, shortened lifespan poor compression blah-blah-blah - I got no idea if its true but why doubt the manufacturer on this? Try using 3-4-5 or gears 4-5-6 (6 speed IIRC?) to vary the rpms. Why not take it easy?

I dunno, do what you feel comfortable with - some cars come from the factory now with full synthetic oil, but they said I was crazy for switching to it at 1700 miles.

Aren't a lot of those expensive engines with standard synthetic oil extensively bench or dyno tested before they leave the factory?

Maybe, and I bet a lot of 'new' cars were taken to redline on a test drive too.

Carl

1 Lucky Texan

Exactly the info I needed. Man, I'm going to baby this motherfu**er like nothing's ever been babied. Yes, even on a 1100 mile road trip.

Thanks!!!

Matt

I've heard that too, spoken as a generality ("All factories now, they run all the engines before they even go in the cars"). Since it's *your* engine, it's up to you to rely on someone who might have done it, or do the recommended procedure yourself. One way you'll know it's been done, right?

Steve

I know I did. Then I went to another dealer that had the exact base model WR Blue Pearl WRX I really wanted at a better price.

I don't know why more dealers don't have tester units that they run until 5,000 miles, sell as used, and then write off the difference. I bought my first car (a '95 Acura Integra GS-R) this way. The sales guy encouraged me to redline the tester, and even drove the thing in third for a mile or so. They also used the car for courtesy rides. OTOH - they had only two models.

For a different view on break-in procedure:

The following is my opinion, just the way I feel, I don't make any claims and I am not looking for argument.

I would think that the engines are run to redline before even leaving the factory, at least briefly. I really don't buy into the whole break-in thing too much. I have not seen any experiments that indicated break-in really does anything at all.

When you think about it, there is metal sliding up and down against metal with fire burning next to it. Whether it occurs at 3500 (perfectly acceptable under most manuf. suggestions) or 5000 rpms (oh god no, not 5k!) doesn't seem all that much different. As long as the cooling system is adequate and well designed, the engine should not be overheating from what I consider normal driving. I wish somebody would do some good documented tests on this subject.

Some old timers tell me about how they "broke in" their engines and how great they ran even in old age. They have strong opinions but they have nothing to compare it to, maybe the engine would run just as good even if they just drove normal from the day they bought it. Its hard to prove either way, so I just don't buy into it.

--Dan

Well I'm not that old of a timer (32yrs). But the reason for the break-in is to let the rings seat. When you have a new or rebuilt motor you hone(scuff up for what type of rings you use, iron, molly,etc..) the cylinder walls. During break in the rings rub against the ruff walls. The rings smooth the wall till the make a tight fit. If you dont wait you can get a problem call blow by. This happens when the rings dont seat. When you you have blow by on the compression stroke air and gas blow past the rings into the crank case. This will raise the pressure in the crank case making your front and rear main seals leak. You lose power and gas breaks down oil and thins it and does'nt protect the motor or bearings very well. It only gets worse overtime and leads to early engine rebuilds. The only way to fix the motor is to rebuild it. I have built alot of motors since I was 16yrs. Most recent a 7000+rpm chevy 327 and just put a Tri-power( 3 x

If it's not true why do all the oil treatments( slick 50, duralube, etc..) say not to your their product during engine break-in? Why they do'nt want your money?

As Rpms built stress on the motor get greater. From what you said cars should not have redline. Why not rev them all to 10k rpm it makes no different? That's why they make rev limiter for car experts like you. As long as the cooling system is

Have you ever done any research to prove that fact? Have you every read a book on basic mechanics? Let alone anything on rotating mass or recipocating forces? Anything on how a 4 stroke motor works?

They have lived it and have experiance. maybe the engine would run just as good even if

It is not hard to prove. What books did you read that had conflicting opinions? Have you every built a motor? I bet you are one of those "Just gas in it and drive " people.

Various and frequent engine speed changes are neccessary to seat the rings properly. Yes, it takes that long to properly break in your car. Take it for a short road trip on a crappy highway with lots of construction. That way your speed will change frequently. You are in a bad spot if you have to drive it to your home directly after purchase. I suspect your car wont last long. And of course keep it under 4k. What are you trying to do, go against every recomendation the manufacturer has?

Rob

Ignore this persons advice. He knows nothing about cars. Perhaps thats why he's here?

Rob

I don't know, but I wouldn't make any assumptions based on the marketing used in snake oil remedies. Maybe they don't want to be blamed if a defective part in a brand new engine breaks. There could be tons of reasons, many having nothing to do with engine break in at all.

I said nothing to indicate that cars should have no redline, I was just saying that we are in fact talking about an engine with burning gasoline and hot metal. The difference between 3500rpm and 5000rpm ain't much-I mean they claim 3500 is OK, so what is going to happen at 5k that isn't going to happen at 3.5k? Fire and hot metal, remember, you are already doing it.. I would be interested in hearing about high mileage engine differences between drivers shifting at 3500 or 5000 on a large number of identical vehicles run under similar terrain and all maintained properly. What the hell, lets even "break" some in by also driving them on cruise control at 90 for at least the first week of driving-as little variation as possible. That'd be the clincher that could make or break the break in theory-the high mileage comparisons.

Uhh, no, I have done no research. In fact, I clearly state that I wish somebody would do some good documented tests on the subject. As far as I know, there haven't been any documented experiments that would say anything either way.

If I pray to a god that I win the lotto and then I win, does that make me correct if I go around telling people that my god is real? If their engine runs good and they have an excuse, is it always correct? In all of the engine break-in writings I have seen, not one includes and cites of actual data. All are the same regurgitated information that has been passed around garages for decades. Did you ever hear that old glass windows sag and are thicker at the bottom? Did you know that is not true? I have had old timers argue with me over that too, and even though they are old and have lived and had more experience-they were told incorrect information and even though they want to believe it-its wrong. The engine break in theory is something people WANT to believe-*it may even be true*-but I have not seen any data to back it up, so to me it smells fishy. Its theory.

Not hard to prove? How do you figure? Its like those TV commercials that show a scan of a human brain from a chronic user of Ecstasy and then show a scan of a human brain from somebody who never used drugs. The brain activity is MUCH smaller looking on the scan for the chronic ecstasy user. So to twist the facts against ecstasy, they say that the ecstasy causes your brain to stop functioning correctly-less activity. But after thinking about it, their argument has no leg to stand on. You see, a chronic ecstasy user is somebody who hangs out in clubs dancing all night. They are malnourished, dehydrated, and mentally stressed. They may sleep only several hours per week. They often use other drugs and alcohol and generally lead a poor lifestyle. So, lets take that person who never used drugs before and lets put them in a club all night dancing several days a week and not feed them properly and let them get very dehydrated. Lets maybe let them get an hour of sleep and then wake them and make then go flip burgers for 8 hours. But maybe only feed them a bite or two cause the chronic ecstasy user probably isn't eating too much either. Lets carry this on for at least a few months--and then scan the brain again. Its like engine break in, damn hard to prove but easy to make a case that on the surface looks convincing. And no, I have built no motors. I do use gasoline however, and I drive.

So all I'm saying, is that for me to believe the break in theory, I need to see some more facts. I know its nearly impossible but like I said above, a high mileage comparison of several identical cars, maintained properly, but "broken in" differently would be much more convincing than listening to an old guy who also swears up and down that glass windows flow.

Sorry so long.

--Dan

This will be my last post defending myself, I don't want to start beating a horse.

Dude, I don't claim to know anything about engine break in, I QUESTION some of the statements about engine break-in and told you why I questioned them. I already said I have never built a motor. I know you are not the only person who thinks I don't know what I am talking about, because anybody who read what said would see I freely admit that I don't know enough about engine break-in to know what the truth is. That is the whole point of everything I have said. It would be nice to know more, but I have not seen any data. I have never even seen a reference or cite pertaining to engine break in. You mentioned books that may contain the information I am interested in. Can you make any recommendations on a book that might cover these topics?

You have been pretty insulting in your last post, I don't like being referred to as ignorant, but its just usenet so I don't really care. I have made not stated anything as fact, I have always either questioned something or said "it seems like", "as far as I know", etc. I have never claimed that you or anybody else said something wrong. You could reply with information relating specifically to something I questioned or observed, but instead you just try to insult me or put me down, alienating me from the rest of the group with statements directed at everybody EXCEPT me.

Again, I would appreciate a recommendation on a book relating to this subject. Preferably a book with some actual data and not just theory. I have certainly heard many theories over the years, but real information is what I would like to see. By the way, did you know that it is now generally accepted by physics experts that centrifugal force doesn't actually exist at all? Another example of a theory that lasted for who knows how many years, but now it is generally accepted as being wrong. It would be nice if you would at least at the very minimum say that my questions are valid questions, rather than insult me. I have already said something to this effect, but engine break-in techniques *might* really make a difference in long term engine life, I am totally willing to say that. It could be true, however I am not ready to buy it yet. Give me some cites and I WILL follow up, I WANT to learn.

--Dan

I would like to make a comment or two on this subject based on several vehicles (Saabs & Volvos) which I bought new, broke in and drove to 150,000

information

This might be of interest to all as to engine break in period. Debunks some old held beliefs.

Wow. This is very interesting, and something I've always wondered about. The piece of information I'm missing to fully understand is: what's different about the oil that's in there that you're not changing for

1,000 miles? Is it actually less-slippery oil that permits "a given amount of friction"?