How Long Does Typical Engine Break-in Really Last ? - for maximum power

[zeroptzero]

If you had to estimate a certain approximate mileage when full engine break-in is complete what number would that be ? At what point does the engine make maximum power, with rings fully seated, and engine wear starts to decrease ?

Planning to dump the factory fluid on my car earlier than the recommended 10k kilometers , but I'm trying to decide who much earlier. My first will will be Amsoil 5w20 SS, but I want the engine fully broken in and rings seated fully and break-in complete.

I've heard various estimates that most break in is done within the first 100 miles, but various manufacturers will list 600-1000 miles. Should I assume that Break-in would not be much longer than 1000 miles and putting in an oil like Amsoil at the 1000 -1500 miles mark would not be an issue. Thanks for reading, and any opinions.

 

[AZjeff]

What car and what does the owner's manual say? TBH you're going to get different answers here and the owner's manual is as valid as any.

 

[zeroptzero]

What car and what does the owner's manual say? TBH you're going to get different answers here and the owner's manual is as valid as any.

My owner's manual describes how to drive for the first 1000 miles, which it describes as break-in. Personally I think that is a long time . I see some engine builders load up an engine for about 20-30 minutes at medium load, and then they start doing full power runs on dynos after that.

 

[Jetronic]

If you had to estimate a certain approximate mileage when full engine break-in is complete what number would that be ? At what point does the engine make maximum power, with rings fully seated, and engine wear starts to decrease ?

Planning to dump the factory fluid on my car earlier than the recommended 10k kilometers , but I'm trying to decide who much earlier. My first will will be Amsoil 5w20 SS, but I want the engine fully broken in and rings seated fully and break-in complete.

I've heard various estimates that most break in is done within the first 100 miles, but various manufacturers will list 600-1000 miles. Should I assume that Break-in would not be much longer than 1000 miles and putting in an oil like Amsoil at the 1000 -1500 miles mark would not be an issue. Thanks for reading, and any opinions.

I'm at 8k miles now and still see improvements. I see it in reduced consumption over a known trajectory, but it does feel peppier aswell. I followed a break-in procedure for the first 1000 miles, gradually increasing loads and the duration of the loading..

I went with an amsoil like oil at 1k miles.... I noticed nothing special between 1k and 6k miles, after that improvements skyrocketed.

On my diesel I bought in 2013, it took over 50k miles to see improvements.

 

[Nessism1]

Full power achieved as soon as the rings seat. Maybe 50 miles?

 

[Patman]

Based off the quarter mile times I would get from a brand new car and then see it get better with more mileage on it I would say that most new engines take a few thousand miles to make their full power potential. That is also what you see with a lot of Car and Driver long term test cars too. They always do acceleration tests when new and then again after 30 or 40k and most of the time the car runs better times at the end of the test.

 

[Nessism1]

Race engines aren't broken in for thousands of miles. They are built, maybe dynoed for an hour at most, then slammed in the vehicle for racing.

 

[zeroptzero]

Based off the quarter mile times I would get from a brand new car and then see it get better with more mileage on it I would say that most new engines take more than 500 miles to make their full power potential. That is also what you see with a lot of Car and Driver long term test cars too. They always do acceleration tests when new and then again after 30 or 40k and most of the time the car runs better times at the end of the test.

That was part of the reason for my question , as I see people claiming to make more power with their cars after a certain mileage - like 7-10k miles. You are right Patman many of the long term tests show cars getting a bit quicker compared to brand new.

I guess tolerances loosen up over time which may lead to more power, and if the rings are mostly seated after a few hundred miles.

 

[zeroptzero]

Race engines aren't broken in for thousands of miles. They are built, maybe dynoed for an hour at most, then slammed in the vehicle for racing.

I have seen that too, many do that .

 

[oldhp]

Race engines aren't broken in for thousands of miles. They are built, maybe dynoed for an hour at most, then slammed in the vehicle for racing.

But those type of engines are built and machined different than the regular street engine.

 

[AZjeff]

Race engines aren't broken in for thousands of miles. They are built, maybe dynoed for an hour at most, then slammed in the vehicle for racing.

And they aren't expected to last over 100k miles and 10+ years either. Not really a great comparison.

 

[gfh77665]

There is no "one answer". Some pre-break in their engines, and some do not. Then, the driving style when new matters too. Long drives at highway speeds are not beneficial, while stop and go city driving with some healthy (but not red line) revs are very beneficial to break in.

I believe in general, most of the break in occours early (by 1000 miles) but it still continues at a more gradual pace for the next 10,000 miles.

 

[Zee09]

My manual said 300 miles.
At 1400 miles everything is still improving.
Past experience says it will continue to 5000 miles...

On another vehicle 8000 miles seemed to be where it settled in.

 

[TomYoung]

I think that this question is impossible to answer. I would consider any vehicle on the street that had been driver 5000 miles as broken in. I would note that I have seen 25,000 mile engines pulled apart with gobs of assembly lube still covering some bearing surfaces. Some cars for a while were sold as requiring no break in period and back in the day, when synthetics became the norm, folks would say that you should break in engines with mineral oil as synthetics were so good that the engine would never break in.

This question is a restatement of this: how long is a piece of string?

 

[Jetronic]

There is no "one answer". Some pre-break in their engines, and some do not. Then, the driving style when new matters too. Long drives at highway speeds are not beneficial, while stop and go city driving with some healthy (but not red line) revs are very beneficial to break in.

I believe in general, most of the break in occours early (by 1000 miles) but it still continues at a more gradual pace for the next 10,000 miles.

I think it takes even longer than that. In essence, they get better and better until they don't and the decline starts.

Obviously the majority of the improvements happens very early, and the quickest decline at the very end.

 

[k1xv]

The most break in occurs at the outset and then gradually declines as the miles pile on. I believe there continues to be improvements after the "break in period" in the manual. On my Corvette, I did not go full throttle until 10,000 miles.

 

[Jetronic]

Of course, transmissions and the rest of the driveline break in aswell. So if we see improvements in mileage or 1/4 mile times it's not convincing to say it's the engine getting better, it could be any number of things.

 

[Gasbuggy]

The LS6 in my old CTSV didn't peak until it hit about 150,000 miles.

 

[WeyounDS9]

The LS6 in my old CTSV didn't peak until it hit about 150,000 miles.

That could also be timing chain stretch retarding your timing.

 

[4WD]

It’s more than the new engine - brakes, suspension, and drive line … dozens of parts …
I take some back roads a few times getting to 500 miles

As for drive it like you stole it - as senseless as Italian tunes