Why do you have to "break in" a new car?

When a new car is assembled, the components of the engine, transmission and other parts need to go through a process where they are "seated" into position. The initial "break in" period causes the nuts and bolts to shift (by 0.01of an inch or less) in a manner that causes them to conform better to the parts that they hold together. Without this process, some of the components may break or work themselves loose.

The process is very similar to getting a new pair of shoes- When you first put them on you tend to walk more gently while the leather and rubber begins to shift conform to your feet. After you finish breaking in your new shoes, then you are able to comfortably walk or run in any manner that pleases you.

If you saw the way that new cars are driven when brand new at the factory you wouldn't bother to carefully break it in.

its called longevity. simply put, your car is like the human body. when a baby is born, it has a "break in" period.....infant to adulthood. this is why we "baby" both so much. everything new has a break in period so it will last longer. its well worth the effort in the long run. i've done it.

fools... dont listen to the other people... the reason you have to break in a new car is because the engine is new... thats all.. everything else doent really matter.... see wat happens is the camshaft is brand new.... and it runs your valves... your valves let gas in.. and exhaust out. now when you start a motor for the first time... that is the part you really break in.. if you dont do it right.. the camshaft wears down... and you are left w/o a new car. sobreak it in right