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

[zeroptzero]

Perhaps what we see is that most of the piston sealing is done by 100 miles (give or take), the time period where hard driving or abusive driving should be avoided is 600-1000 miles (give or take), but engine wear continues and tolerances open up on engine and drivetrain for up to 10,000 miles or more. This is what I'm taking away from the replies here.

With the question I was trying to understand how engines break in over time, so there seems to be various stages, and it can extend for a long time on some vehicles.

I'd have a very hard time not going WOT for 10,000 miles, but everyone is different and have different situations and vehicles to consider. That would take a lot of self-restraint, especially with a Corvette

 

[4WD]

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

Yep. Like balanced and blueprinted - aftermarket parts …

 

[Patman]

I'd have a very hard time not going WOT for 10,000 miles, but everyone is different and have different situations and vehicles to consider. That would take a lot of self-restraint, especially with a Corvette

For my 2018 Corvette, GM recommended not going full throttle for the first 500 miles. They even had the “redline” on the dash showing itself to be 500 rpm less (although you could still go to the actual redline if you wanted). I drove rather gently during the first 500 miles with the exception of one full throttle blast around the 300 mile point. I racked up the 500 miles pretty fast though so it wasn’t like i had to wait a year to go WOT.

With the 1998 Firebird Formula that I factory ordered new, I drove it HARD from day one. On the way home from the dealer I hit the redline in the first four gears. That first evening I took about 3 or 4 friends out for a ride in it and each time I went full throttle in the first 3 gears. A week later I took it to the track and made 16 quarter mile runs That car was a very strong runner too, I like to think that the strong break in might have helped it make a little bit more horsepower. (It’s best quarter mile was a year later, it went 12.68 at 110.6, with 4.10 gears, drag radials, and just a few low cost mods but the engine was completely stock)

 

[Nessism1]

Engines built at auto assembly plants are NOT babied. They are fired up on a dyno, and after a brief warm up period, they get fed high throttle and high rpm. Cars coming off the end of the line are likewise run hard. Placed on rollers, techs slamming the throttle down, bringing the vehicle up to modern highway speeds. No pussyfooting around.

 

[zeroptzero]

Engines built at auto assembly plants are NOT babied. They are fired up on a dyno, and after a brief warm up period, they get fed high throttle and high rpm. Cars coming off the end of the line are likewise run hard. Placed on rollers, techs slamming the throttle down, bringing the vehicle up to modern highway speeds. No pussyfooting around.

You know the car jockeys hammer them for sure, from the auto plants to the transport trucks, and then the dealers. My new Subaru BRZ had 10 kms on it when I picked it up at the dealer, a similar model that was also at the dealer had 280 kms on it, I made sure to buy the one with 10 kms.

 

[oil pan 4]

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.

It appears that modern engines are pretty much broken in by the time they're installed into the vehicle.
Most of the forbidden glitter is made well within the first 1,000 miles.

 

[Jetronic]

Perhaps what we see is that most of the piston sealing is done by 100 miles (give or take), the time period where hard driving or abusive driving should be avoided is 600-1000 miles (give or take), but engine wear continues and tolerances open up on engine and drivetrain for up to 10,000 miles or more. This is what I'm taking away from the replies here.

With the question I was trying to understand how engines break in over time, so there seems to be various stages, and it can extend for a long time on some vehicles.

I'd have a very hard time not going WOT for 10,000 miles, but everyone is different and have different situations and vehicles to consider. That would take a lot of self-restraint, especially with a Corvette

I did go WOT the week before the first oil change at 1000 miles. WOT from rolling until high into illegal speeds actually. Wanted whatever metal that would shed to come out with the 1000 mile change.

 

[PontiacHO]

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.

With much different clearances and internals than your street engine. There’s also more drivetrain components and accessories to be considered during break-in with a new-factory assembled vehicle. No comparison for race-dyno process.

 

[Dave Hess]

My last new car I hit 115 miles per hour on the way home (country highway) no traffic.

Zero harm to engine with only 50 miles on odometer.

 

[melk]

Besides seating the rings what else occurs during break in?

 

[Strumpan_]

Engines built at auto assembly plants are NOT babied. They are fired up on a dyno, and after a brief warm up period, they get fed high throttle and high rpm. Cars coming off the end of the line are likewise run hard. Placed on rollers, techs slamming the throttle down, bringing the vehicle up to modern highway speeds. No pussyfooting around.

Also on the dyno they go up to 100% load, not just low load high rpm. Going 10k miles babying a car is just not it. I’’d drive slower for like 3-4 tanks then just drive normally. They build the cars for the people who don’t know what engine oil is. They design them so they can be driven hard to the soccer game next Sunday.

 

[Alain2]

My last new car I hit 115 miles per hour on the way home (country highway) no traffic.

Zero harm to engine with only 50 miles on odometer.

Did the same years ago with a lease Mercedes, dealership was located by the highway. Car had less than 10 kilometres on it before hitting speed limiter. I would never do that again, but that is the story. I changed the oil once per year (every 18’000km). When I returned the car 3 years later it was not burning any oil, never had an issue with the car in fact.

 

[Cujet]

20 minutes of hard use will break in any engine. Light use takes longer.

We did dyno testing of production engines for camshaft development. Teardowns never indicated any issues what so ever. The engines got a leak check run, a few heat cycles to ensure everything was within spec, and then full power runs. The idea that something bad happens if an engine is run at full load and full RPM is in error.

There was never any bearing scoring, never any cylinder wear issues, no ring gap increase or valve/cam/follower wear. We did hundreds of runs, I was involved with something like 150+.

There are Google examples of cylinder problems. Almost always with a used engine that was improperly rebuilt. Factory fresh engines are assembled correctly.

Change the oil at 1000 miles and go on your way.

 

[02SE]

Here's a fairly aggressive break-in. The yellow Hayabusa has 351 miles on it at the time of this video. Their lack of riding gear would not be my choice.

 

[zeroptzero]

Here I am worrying about when I can take my 7500 rpm engine beyond 4000 rpms, lol then I see these guys on the bikes, wow.

 

[Ranger83]

FWIW we logged every tank of fuel from new for our 2006 Subaru Outback 3.0R [flat six]. We changed the oil at 1,000 miles, then regular intervals.

The MPG continued to increase for the first 9,200 miles then leveled off. That car was retired with 257,000 miles on all-original engine.

 

[BMWTurboDzl]

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.

Depends on the type of liner and ring material.

 

[RedSpider]

I have worked in dealer retail sales, worked in service, worked at my local and several out of state auctions, and I have known and worked with a good number of people who have worked at the assembly factories for various models...Your brand new car has seen redline many, MANY times before you sat in it.... 100% guarantee it. Those 5-10 miles on the odometer when you first hopped in it were the most abusive and tortured miles most cars will ever see. Break it in as gently or as hard as you want, its seen worse, I assure you.

Most modern production cars, I personally dont think it matters much. By the time you took delivery of it, it had been around the block (literally and figuratively) enough that whatever you do to it matters little.

 

[k1xv]

Besides seating the rings what else occurs during break in?

Thermal heating and cooling of cast metals, such as in pistons, relieves internal stresses in the materials.

 

[KrisZ]

People that constantly worry about their vehicles must have some really boring lives. When the car is new you need to baby it to let it break in. Once it has some miles under the belt you need to baby it so it doesn’t break down.

When do you people enjoy your vehicles?