Classic vs Modern Engine Break-In

break in oils usually contain high amounts of zinc/phosphorous which is harmful to modern car emission systems. Just follow the manufacturer’s process for break-in. Varying speeds don’t accelerate and brake aggressively I wouldn’t sweat it. Modern synthetics do an exceptional job in what they were intended for.





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My 2018 Hyundai manual says the motor is broke in either at 600 miles.


VEHICLE BREAK-IN PROCESS

By following a few simple precautions for the first 600 miles (1,000 km) you may add to the performance, economy and life of your vehicle.

  • Do not race the engine.
  • While driving, keep your engine speed (rpm, or revolutions per minute) between 2,000 rpm and 4,000 rpm.
  • Do not maintain a single speed for long periods of time, either fast or slow. Varying engine speed is needed to properly break-in the engine.
  • Avoid hard stops, except in emergencies, to allow the brakes to seat properly.
 
Anecdotal: Years ago I was regularly working as a vendor at a major auto manufacturing plant. While working around the facility I noticed that periodically one the vehicles would be taken straight off the line outside for what appeared to be 0-60/60-0 test. WOT from full stop then an immediate hard brake to full stop. I witnessed this event over many months and many vehicles.

I once owned one of the same vehicles made at that specific plant. Never had issues with the engine. And who’s to say mine didn’t have the same thing happen to it. This was one of the contributing factors that made me realize how much I was probably overthinking break in/break in oil changes on modern vehicles. I run the intended interval and just drive like normal from day one.
Years ago I watched the documentary on the Ferrari 599's being built. Every car was driven prior to being sent off for shipment to dealers.

I had wondered, what about the odometer? I am pretty certain it doesn't count, the predrive. What if a stone hit the paint? They were so painstaking in measuring its depth and redoing if any variance. I suppose the Michelin PSS's are going to have more miles than the odometer indicates.

Not only do I agree we're overthinking, but with car leasing and the general decline of the attitude and concept of mechanical sympathy, I don't even think breaking in matters. I'm pretty sure over my lifetime I've wasted tons of resources treating mechanical things theoretically. My last brake jobs have taken the pads down to 85%+ worn (two jobs ago, the squealers kicked in, and to my delight, they don't damage the rotors--that was a first). I used to look at my brakes, and do the, well they're only half worn but I'm already in there....what a waste. Also, tires look worn time to get new ones. Now I take them down to 2/32". We're fortunate we have the financial resources to waste. Time, money, thought, etc. Other parts of the world often cannot.
 
  • Avoid hard stops, except in emergencies, to allow the brakes to seat properly.
It's hilarious that BMW says the same thing, though at least 35% of a forum says the brakes need to be bedded. I did a brake job at home and followed the bedding procedures. I wanted to shoot myself. My brand new rotors were orange they got so hot. I thought, man, I sure am a kid who has to touch the stove to get burned, to conclude the stove was hot.

One of the respected guys on the forum said, don't you remember when your car was new, either reading the manual, or, there was a hang tag on the rearview saying to go easy on the brakes for the first x km? We're all susceptible and will always be, to getting conned on the internet.
 
I think its much less about modern vs classic cars and much more about cleanliness of assembly and machining.

I still exercise restraint on a new car, but they are mostly broken in when you get them.

Basically i do this.

  • Do not maintain a single speed for long periods of time, either fast or slow. Varying engine speed is needed to properly break-in the engine.
 
Do you actually know that they dumped them because of high oil consumption? I think it was word of mouth that above 100k miles they would fail. I know lots of people including family members who did not have that kind of experience... an uncle who's owned many different brands said his most reliable vehicle was a 78 Oldsmobile Delta 88 350 rocket that he kept for over 300k miles and it didn't burn a drop of oil, just had a slight rest main seepage. Pretty sure the over 100k an old engine was a myth spread over time.
From my own life experience in my little world wherever a vehicle reached 100k miles the original owner was looking to unload it. Sure you can keep a vehicle for as long as you're willing to maintain. My father had a late 70's Bonneville burned oil and so did mother's Pontiac. My '65 Mustang was an oil burner. 1980'-1990's were a new era.
 
It's hilarious that BMW says the same thing, though at least 35% of a forum says the brakes need to be bedded. I did a brake job at home and followed the bedding procedures. I wanted to shoot myself. My brand new rotors were orange they got so hot. I thought, man, I sure am a kid who has to touch the stove to get burned, to conclude the stove was hot.

One of the respected guys on the forum said, don't you remember when your car was new, either reading the manual, or, there was a hang tag on the rearview saying to go easy on the brakes for the first x km? We're all susceptible and will always be, to getting conned on the internet.
Liability. I'm in the camp that the owners manual is written to give the owner time to become familiar with the driving characteristics of the vehicle vs break-in the drivetrain to insure maximum power and longevity.

Take BMW for example. Compare what Brembo says vs what BMW with Brembo says.

You brake rotors should never get red hot from being run in.
 
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Liability. I'm in the camp that the owners manual is written to give the owner time to become familiar with the driving characteristics of the vehicle vs break-in the drivetrain to insure maximum power and longevity.

Take BMW for example. Compare what Brembo says vs what BMW with Brembo says.

You brake rotors should never get red hot from being run in.
I will never do this again. 60-20 mph, 10x and never stopping. Maybe it’s true, but isn’t it a bit silly to say you can’t stop fully? How realistic is that if we live among other people?

Again, a pretty respected guy on the forum agrees this is not applicable to BMW OE, which is my scenario. Brembo? Who knows. I still wouldn’t do it again.

  1. Make eight to ten near-stops from 60mph to about 20 mph. Do it HARD by pressing the brakes firmly, but do not lock the wheels or engage ABS. At the end of each slowdown, immediately accelerate back to 60mph, then apply the brakes again. DO NOT COME TO A COMPLETE STOP! If you stop completely, with your foot on the brake pedal, pad material will be imprinted onto the hot rotors, which could lead to vibration and uneven braking.​

 
If you’re doing that type of break in for the brakes, it’s a good idea to go out into a rural area where there is no traffic. You definitely don’t want to be fully stopped with red hot brakes and risk ruining your new pads and rotors like that. I have done this type of break in on new brakes a couple of times but saw no difference compared to breaking them in with just normal driving. So I haven’t done anything like this in about 15 years now.
 
I will never do this again. 60-20 mph, 10x and never stopping. Maybe it’s true, but isn’t it a bit silly to say you can’t stop fully? How realistic is that if we live among other people?

Again, a pretty respected guy on the forum agrees this is not applicable to BMW OE, which is my scenario. Brembo? Who knows. I still wouldn’t do it again.

  1. Make eight to ten near-stops from 60mph to about 20 mph. Do it HARD by pressing the brakes firmly, but do not lock the wheels or engage ABS. At the end of each slowdown, immediately accelerate back to 60mph, then apply the brakes again. DO NOT COME TO A COMPLETE STOP! If you stop completely, with your foot on the brake pedal, pad material will be imprinted onto the hot rotors, which could lead to vibration and uneven braking.​


It depends on the brake system. Proper bedding helps avoid complaints about brake noise on HP brake systems. Not such a big deal on basic systems.

Anyways here's Brembo for various brake systems. None of matches what zeckhausen is recommending.

 
Do you actually know that they dumped them because of high oil consumption? I think it was word of mouth that above 100k miles they would fail. I know lots of people including family members who did not have that kind of experience... an uncle who's owned many different brands said his most reliable vehicle was a 78 Oldsmobile Delta 88 350 rocket that he kept for over 300k miles and it didn't burn a drop of oil, just had a slight rest main seepage. Pretty sure the over 100k an old engine was a myth spread over time.

From my own life experience in my little world wherever a vehicle reached 100k miles the original owner was looking to unload it. Sure you can keep a vehicle for as long as you're willing to maintain. My father had a late 70's Bonneville burned oil and so did mother's Pontiac. My '65 Mustang was an oil burner. 1980'-1990's were a new era.

The 289 V8 engine on my '65 Mercury Comet was shot at 80,000 miles. Had already required a valve job, was smoking on deceleration and using oil.

Anecdotally speaking it seemed that a lot of Fords in that era smoked. GM engines seemed to last a bit longer.

For what its worth, Massey Ferguson used Chrysler 225 slant 6s and GM 327 V8s in their combines. Smaller combines came with the 225, larger ones with the 327.
 
Do you actually know that they dumped them because of high oil consumption? I think it was word of mouth that above 100k miles they would fail. I know lots of people including family members who did not have that kind of experience... an uncle who's owned many different brands said his most reliable vehicle was a 78 Oldsmobile Delta 88 350 rocket that he kept for over 300k miles and it didn't burn a drop of oil, just had a slight rest main seepage. Pretty sure the over 100k an old engine was a myth spread over time.
My dad bought a brand new valiant in 1968. By the time it had 100k on it it was getting tired. By the time it had 150k on it it was using so much oil it would foul plugs in just a few miles. I put valve stem seals in it but that was not the problem.
 
The first forklift company I worked for also did fleet vehicle fleet maintenance and repairs and the vehicles were put into service with out any voodoo break in procedure and ran fine as they aged and lasted .
 
break in oils usually contain high amounts of zinc/phosphorous which is harmful to modern car emission systems. Just follow the manufacturer’s process for break-in. Varying speeds don’t accelerate and brake aggressively I wouldn’t sweat it. Modern synthetics do an exceptional job in what they were intended for.





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Fwiw, Honda no longer recommends varying engine rpm during break-in. So, basically go easy on the throttle for the first 600 miles.
 
The 289 V8 engine on my '65 Mercury Comet was shot at 80,000 miles. Had already required a valve job, was smoking on deceleration and using oil.

Anecdotally speaking it seemed that a lot of Fords in that era smoked. GM engines seemed to last a bit longer.

For what its worth, Massey Ferguson used Chrysler 225 slant 6s and GM 327 V8s in their combines. Smaller combines came with the 225, larger ones with the 327.
My experience is mostly with GM (Chevy and Oldsmobile) engines 1970s and 80s but my dad's family had Mopars in the 60s and 70s when he was growing up. My best friend who's much older than me is a retired mechanic and his experience was mostly with Ford as he worked at Ford dealerships. Just like today there was good engines and bad engines back then.
Better oil and unleaded gas, along with taller gear ratios and overdrive transmissions pushed their longevity a lot further. It's not that they couldn't make any decent engines back then.
 
break in oils usually contain high amounts of zinc/phosphorous which is harmful to modern car emission systems. Just follow the manufacturer’s process for break-in. Varying speeds don’t accelerate and brake aggressively I wouldn’t sweat it. Modern synthetics do an exceptional job in what they were intended for.





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In the air force when we would get a new piston engine for a generator or a brand new zero hours diesel generator unit in we would break them in on the load bank at half the rated load for 20 minutes then run at rated load for an hour. On gas turbines we wouldn't bother breaking them in.
 
Don't baby it, and don't beat it. Use a decent amount of throttle to accelerate up to 4K RPM, then decelerate for a while with fully closed throttle (puts a vacuum in the cylinders) ... repeat that cylinder "pressure/vacuum" cycle as much as possible to properly seat the rings. I have bought a few vehicles where I had to drive them pretty long distances back home on highways, and I would still try to do the accelerate/decelerate cycles when traffic allowed.
 
Don't baby it, and don't beat it.
I'd agree with your sentiment, but there was a theory in the late 60s and early 70s (I'm a mechanical engineering graduate of 1971) that you could get better performance out of an engine by beating on it from the time it was new. That idea even had a name but I no longer recall it.

Probably long since discredited.
 
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