What Subaru of America says about the "break-in period"...

[SurfAndSand]

I just finished my initial "break-in" period. 50 miles. I warmed the car to operating temperatures, smoothly varying speeds between 5-20 mph, without bogging the car. Then when traffic cleared out, I would pull at almost WOT from about 2500 to 5500-6000 rpm in 2nd, then engine brake down to about 3000, and then pull again in 3rd, and then engine brake, and then do it all again in 4th gear. 4th I wasn't able to get that high, because I wanted to keep it under 65-70 mph.

This is the first time I've broken in a car at higher loads. I usually break mine in following the manual - gently gently around 2-4k revs, and always under 60 mph. I guess I'll get to see if anything weird happens with it.

I read an article in popular mechanics magazine, that suggested a similar break-in procedure to "seat the rings" - Not just the fanatical motorcycle engine builder.

What I got from the article was: use higher loads without bogging, and without redlining the engine. How do you do that without a dyno to simulate load? Pull in higher gears, but not from low rpms, and not too high. I did this on the freeway up a slight incline to help with the load. I'm sure the traffic behind me was pissed from me speeding up and slowing down seemingly erratically. I would pull over and let traffic through, so I could run this thing a couple times. My wife was getting sick from my bad driving.

[Suberman]

Originally Posted by BrokenNocturne

Thanks! This is really good advice. I was wondering how I should drive mine after break in periods. Also, is this more important for MT than AT or about the same? (I know, it's sad to have an 86 in AT, but I live in a terribly traffic congested area where MT would be miserable).

Thanks for your advice!

Break in is actually easier with an automatic left in Auto mode. You really have to try to make the mistake of overworking the engine. With an automatic in Auto mode just avoid full throttle and vary your speed and throttle opening from time to time. Also, manually selecting a lower gear for short periods works well, keeping rpm below 4,000 for as much if the run as possible. As Subaru allows, occasional use of higher rpm or more throttle is permitted in an "emergency". I found I was having more emergencies behind the wheel of my BRZ than I remember having in other cars....we'll see how well I did eventually. Currently my engine runs strong right up to the flashing red dots and at full throttle.

Patience is rewarded.

[kuhlka]

Originally Posted by Suberman

Break in is actually easier with an automatic left in Auto mode. You really have to try to make the mistake of overworking the engine. With an automatic in Auto mode just avoid full throttle and vary your speed and throttle opening from time to time. Also, manually selecting a lower gear for short periods works well, keeping rpm below 4,000 for as much if the run as possible. As Subaru allows, occasional use of higher rpm or more throttle is permitted in an "emergency". I found I was having more emergencies behind the wheel of my BRZ than I remember having in other cars....we'll see how well I did eventually. Currently my engine runs strong right up to the flashing red dots and at full throttle.

Patience is rewarded.

Manual mode in an automatic is ideal because you can vary the RPM. Speed is only relevant with regard to the load put on the engine when accelerating and decelerating. I broke my car in over the first weekend I owned it on a 500 mile trip to Ohio (another 500 back). For most of the trip I varied my speed. I'd cruise in 6th in auto mode for a few miles, then switch to doing intervals of acceleration and engine braking for a few miles until I hit 250 miles. Every 100 miles I bumped up the RPMs another 500 until I was running bursts up to 6,000 RPM then back to 3,000 in every gear (except 5th/6th because that'd mean doing way over 100mph).

The first 100-250 miles are the most critical, then after that it's just a matter of varying gear and doing lots of moderate acceleration and engine braking. I've done this with seven vehicles and none have ever had engine issues. In fact every time I've had the oil pan dropped, mechanics marveled that my engine looks like-new. Sane but aggressive break-in and frequent oil changes with full-synthetic is key to engine life. It also helps if you get your engine tuned to make sure it isn't running excessively lean anywhere.

The reason we won't get an answer in writing or over the phone about 'voiding' a warranty is because legally they can't ever void a warranty. If that rep were to say slapping the red line for the first 1,000 miles won't 'void' your warranty, you could use that email in court if your car blows up and they refuse to repair your car.

The Magnuson-Moss Act states the manufacturer must prove an aftermarket modification or specific operation caused damage to the part in question. This is why break-in is listed as a recommendation and a single part being modified or replaced with an aftermarket bit only means that part is no longer covered by the warranty. The warranty still covers the rest of the car, unless the manufacturer can prove changing to an aftermarket spark plug caused your exhaust to fall off, or changing tires caused your head unit to short out. If ANYONE at a dealership ever says your entire warranty is voided, they're full of crap and you should start looking for a good lawyer.

[Suberman]

I agree the manual mode automatic is fine for break in. My point was just that driving around in automatic mode is a pretty fool proof way to break in an engine. The transmission will upshift early if you don't have your foot to the floor. However, on a long highway trip manually selecting a lower gear periodically is a good idea.

I also agree that the restrictions become less important as mileage accumulates. All engines will be run in at 1,000 miles but some may run in earlier. Depends how they are driven. 1,000 miles is specified as a conservative number.

[pche]

Originally Posted by mav1178

And what is your proof?

Please do not link me to a site that talks about breaking in a motorcycle's pistons.

-alex

I guess I don't have a concrete proof. Just speaking from experience, and a little bit of common sense. I've built and tear down quite a few engines in my long and uneventful automotive career. Most of them were low mileage stock engines. The evidence of rings not seated properly is obvious when you have the pistons out and inspect the cylinder walls.

I've beat the shit out of all my new motors when I first got them to seat the rings, haven't had one fail me yet. I've never read the article you mentioned about breaking in motorcycle engines. However I don't see how it would differ from a cars engine. A 4 stroke internal combustion engine is the basically the same and should be treated the same, regardless the size or how many wheels are "connected" to it.

All that said, I'm not telling anybody not to follow the manufacture procedure, its your car, I'm just a guy on the Internet....

[Sbeezy]

@pche this is the article you are speaking of
http://www.popularmechanics.com/cars...k-in-a-new-car

Ive talked to quite a few mechanics and guys who build race engines and the consensus has been the same beat the shit outta it for the first 20-50 miles and then change the oil.

[Suberman]

Originally Posted by Sbeezy

@pche this is the article you are speaking of
http://www.popularmechanics.com/cars...k-in-a-new-car

Ive talked to quite a few mechanics and guys who build race engines and the consensus has been the same beat the shit outta it for the first 20-50 miles and then change the oil.

Race engines are totally different.

[Sbeezy]

i was supposed to put and race. oops my bad lol