How to Break In a New Engine (7 Tips to Prolong Your Vehicle)

Buying a new car is exciting. Nothing quite beats the new car smell and the easy maintenance afforded by a new engine.

If you just bought a new car, chances are you want your new engine to last a good 20 years, or at least until you decide to upgrade. How you break in a new engine can have an impact on the lifespan and health of the engine over time.

What Does It Mean to “Break In” a New Engine?

“Breaking in a new engine” refers to a process carried out with either a new or rebuilt engine to ensure all of its components properly seat and function together smoothly. During the break-in period, the engine’s moving parts, particularly the piston rings, cylinder walls, camshaft, bearings and other components, wear in a controlled manner to create a tight, efficient seal.

The break-in process generally involves running the engine under varying loads and speeds for a certain mileage or time period. Manufacturers often provide specific guidelines for this process.

The goal is to allow the engine components to mate together and wear in a manner that promotes longevity and performance. Proper break-in can help ensure the engine delivers its designed power output, maintains good fuel efficiency, and reduces oil consumption and emissions over its lifespan.

new car keys

Tips for Breaking In a New Engine

Breaking in a new engine is pretty straightforward. Here are some general tips to help your engine outlast the life of the vehicle.

1) Follow the Manufacturer’s Recommendations

Nobody knows your vehicle better than the engineers who designed it. When a manufacturer includes a break-in in the owner’s manual, you should follow that procedure (even if it deviates from this guide).

Many manufacturers include guidelines for engine break-in that look something like this: for the first 1,000 miles, vary the engine speed, avoid full throttle, and stay under 4,000 RPM.

Modern vehicles save telemetry data to the ECU. If you ever need to bring your vehicle in for warranty work, there’s a chance the tech could check the vehicle’s computer to see how fast you were going, what the max throttle percentage was, and what your max RPM was.

If you were driving the vehicle hard before you’ve reached the target break-in mileage, that could potentially cause issues with engine warranty work.

Example from 2020 Dodge Charger (w/ 6.2L Hemi engine) owner’s manual:

engine break in procedure
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2) Avoid Redline

As an engine breaks in, bearing surfaces and rotating components mate to each other. Small bits of metal wear away during the first few thousand miles you put on an engine. Once the engine stabilizes, wear will be minimal as long as you’re taking care of the engine.

If you run an engine really fast before it is broken in, you may actually damage the engine. This could be damage to the bearing surfaces, the cylinder walls, or piston rings. This is especially true if you run the engine hot while you’re revving it up.

3) Avoid Full Throttle (At Least At First)

For the same reasons that you want to avoid redline, you should also avoid full throttle if possible. Full throttle puts more load on the engine, which stresses the components that may not be fully broken in.

An engine that wasn’t broken in correctly may experience more blow by and oil consumption as it ages. In extreme cases, you could even spin a bearing. A spun bearing will require a rebuild of the engine’s bottom end.

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4) Go Easy on the Clutch

If your engine is new, chances are the rest of your car is as well. This means there are other components that need to break in up to 1,000 miles, such as the clutch.

If your new vehicle has a manual transmission, it is totally normal to smell a bit of a burnt clutch smell, even if you’re easy on the clutch when you drive. This smell should mostly dissipate within the first few thousand miles. 

5) Vary the Engine Speed (Avoid Cruise Control)

When you vary the engine speed during a break in, you are helping the piston rings seat evenly. Although cruise control is not hard on the engine, running cruise control for long distances during break in could interfere with this process.

6) Avoid Idling

For the same reasons you want to avoid cruise control, you also want to avoid idling. Idling runs the engine at a single low RPM. You also do want some load on the engine.

The engine will break in best at operating temperature while running at various loads. As you put miles on your new engine, you can gradually increase the maximum load you apply to the engine.

7) Drive Around Town

Driving around town is an easy way to naturally vary the load on the engine. When you are in stop and go traffic or driving from stoplight to stoplight, gentle intervals of acceleration and coasting are good for a new engine.

Engine Wear and Break In

Engines will naturally see more contaminants in the oil at the beginning of their life due to the break in process. If you do a used oil analysis, you will notice these extra contaminants start to thin out and go away over the first 10,000 miles or so.

Some common elements you will notice on your oil report that are higher than average are copper, aluminum, and silicon. As you put miles on the vehicle, these values will likely drop to single digit parts per million (PPM).

Fun Fact:  Although engines are rated for a specific amount of horsepower by the factory, there will be slight variances from engine to engine on each vehicle. An engine that is properly broken in will often make more power than one that is not.

Fuel economy is also typically better on a healthy engine. Following the break in procedure will set you up for success, maximizing your chance for a great ownership experience with your new vehicle. 


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