Blog: How to properly break in a new engine

So you have a new car and now it’s break in time, but what should you do? How do you properly break in a engine? The internet is full of all different kinds of advice, so whats the right advice to follow? Don’t worry I have an answer for you and its not hard at all. But you do need two key ingredients to do the job right, patience and discipline (And for the love of all that is holy do not Google! Its worse than looking up sickness which always results with cancer.).

 

What are the goals of a good engine break in?

1: Seat the piston rings with cylinder walls

2: Seat the Valves

3: Allow for final engine tolerance adjustments

In other words give the 1000 individual pieces of your engine time to settle in.

 

Dan’s rules for new car break in:

1: READ THE OWNERS MANUAL! Seriously, its easy to forget it’s there but your manufacturer may have put a specific process in there for break in. Because this applies to your warranty be sure to follow that first, then after that any other recommendations second.

2: Follow the recommended oil change interval, there is no need to change your oil early unless the manufacturer states to do so. If your worried about wear metals from the break in process, then stop. Keep in mind that engineers plan on any additional wear metals as a part of the break in process and the overall engine tolerances (See goal #3). You also have an oil filter there to help trap harmful contaminants and most manufacturers tend to use an heavy duty oil filter from the factory. 

3: Do not use synthetic oils earlier than 3,000-4,000 miles unless the manufacturers maintenance schedule calls for it. Because of the specific properties of synthetic it actually does not make a good break-in oil. Now there are different honing processes that are used on cylinders and different metals for cylinders that can change a manufacturers recommendations for oil types, but if you change to synthetic oils too early you can prevent your rings from properly seating. This also goes for any top off oil that is needed, if you need to top off use a conventional oil that meets the manufacturers recommended specifications.

4: Do not let the engine idle for sustained periods of time! Its fine if your in the middle of stop and go traffic, but if your trying to let the car warm up because its a cold day don’t do it! Suffer with the cold, your engine with thank you for it.

5: Make sure to vary the engine RPMs during the first 1000 miles. If you have a common route to work thats mostly highway miles find a different route for a little while that mixes city and highway driving. Part of the purpose of this is to help with the mechanical variances (resonance as an example) that occurs with different loads and RPMs. This also helps with loading on the compression rings themselves which also aids in a good break in.

6: By the miles:

up to 500 miles - Light to moderate acceleration (remember to vary engine RPMs) and little to no engine braking if you drive a manual transmission. 

500 to 750 mile - Moderate acceleration and light to moderate engine breaking

750 to 1000 miles: Short spurts of heavy acceleration (merging on the highway is a good place to do this) and moderate engine braking

1000 to 3000 miles: Drive like you normally do, be sure to follow the owners manual for your maintenance schedule and PLEASE, PLEASE do not beat on your car unless your willing to pay to fix it!