What’s Break in Oil?

You’re finally finished rebuilding that car engine and now it’s time to break it in, or the process of making sure all the components of the engine are fully mated and working correctly. This is the final step of rebuilding your engine and vital for the rebuild to succeed and you want to make sure everything goes as planned. For that, yout need the correct engine oil, From convential to syntheitic and with so many additives it can be hard to determine which oil is best for your engine needs.

Break In Oil

Of the many different types of engine oils available to car owners today, experts recommend a conventional oil with a high zinc/phosophorous (ZDDP) and moly anti-wear compounds to provide extra protection between components during the break in process. Because of this special anti-wear chemistry provides by these additives found in the conventional oil, break in oil provide an extra level of lubricant that aids the break in process and allows for the engine to become fully functional without placing extra stress on its load bearing parts. Although it varies by model and engine type, the break in process lasts anywhere from 500-1,000 miles. Once that distance has been reached, your engine will be ready to use regular oil and break in oil shouldn’t be used past this point.

Where to Find Break In Oil

Because of the high levels of ZDDP (thought to increase emissions), not many mass merchanisers, such as AutoZone and Walmart, sell break in oil due to the amount of regulations involved with oil. So where can you find it? You will need to look for them in speciality stores such as VP Racing Fuels or find them online at places like Lucas Oil. If you’re not sure what brand or type of oil to use, contact an engine building company or the car manufacturer and they can give you a recommendation.


Building your own engine is an adventure and investment that can take months or even years. The final step of breaking in the engine is one you want to do successfully and easily. For that to happen, you need break in oil, an oil specially designed to increase lubrication and facilitate the engine becoming fully mated. Pick up some at your local speciality store and keep enough to properly break your engine in and the engine will be working order in no time!