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Break your engine in the right way

Or pay a hidden, steep price for your new car later.

Brian Cooley Editor at Large
Brian Cooley is CNET's Editor at large and has been with the brand since 1995. He currently focuses on electrification of vehicles but also follows the big trends in smart home, digital healthcare, 5G, the future of food, and augmented & virtual realities. Cooley is a sought after presenter by brands and their agencies when they want to understand how consumers react to new technologies. He has been a regular featured speaker at CES, Cannes Lions, Advertising Week and The PHM HealthFront™. He was born and raised in Silicon Valley when Apple's campus was mostly apricots.
Expertise Automotive technology, smart home, digital health. Credentials
  • 5G Technician, ETA International
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Brian Cooley
2 min read
Toyota

I bet the dealer didn't go over your new car's break-in procedure with you, leaving you to dig it up on page 79 of the tediously written owner's manual. 

Luckily, most cars have a fairly similar break-in procedure so even if you refuse to read your manual, you can do it successfully.

Watch this: How to break in your new car's engine

The reason for the break-in period is to mate the engine's friction surfaces to each other in the smoothest manner, so they seal or rotate against each other with minimal leakage or friction. That can result in better fuel economy, lower oil usage, better power delivery and longer engine life at the end of the car's career. That's a nice payoff for less than a thousand miles of restraint up front.

Take a look at this table of break-in guidelines from a 2018 Mercedes GLC, 2018 Hyundai Elantra  and 2018 Toyota RAV4 . Different manufacturers, but fairly similar guidelines.

GLC

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Elantra

RAV4

Miles

1,000

600

200-600

Load

Vary, avoid top speed

Vary, avoid top speed

No towing (500 mi.)

RPM

2/3 of maximum

2,000-4,000

Vary (600 mi.)

Full Throttle

No

No

No

Braking

No engine braking

Avoid hard stops

Avoid hard stops (200 mi.)

Read your car's manual, of course, but it will probably boil down to a four-point plan along these lines:

  • No top speed or wide open throttle (WOT) 
  • Vary your RPM across the middle of the range while driving. 
  • Avoid hard stops, so your brakes settle in nicely.
  • No towing.
piston-rings

Your engine is basically a friction factory. The engine break-in period gets the parts used to each other so they beat up each other a little less.

 MAHLE North America

One more thing I would personally do is change the engine oil and filter at the end of the break-in period. This is an old-school technique, but the thinking goes that an engine throws off the most metal particles during break-in and it's good to flush those out. 

The computer control modules in modern car engines, transmissions and braking systems could probably enforce the break-in steps automatically today, but car owners would bristle at that much forced limitation and it could be dangerous to hobble a car's performance in case an emergency situation arises.