Mechanics Take Aim: New Car Break In

Every car salesman and mechanic I have ever met has had their own ideas about what special treatment you should extend to a new car. The advice I've heard most often has been stuff like "Don't go over 55 for at least 500 miles" and "don't wax it for at least six months". After my recent new car purchase I decided to ask my brother's advice. He's an ASE certified mechanic who graduated from Nashville Auto Diesel College. I didn't just want his advice, I wanted him to elicit advice from his old professors. This is what I found out.

Engine

While it's not a good idea to run a brand new engine at high RPMs for the first few hundred miles, there is an important step to making your engine run right that is not as widely known mostly because it seems counter-intuitive. New piston rings must be snugged up against the cylinder walls with high pressure that is derived from combustion. In simpler terms, your engine will lose efficiency if you take it too easy on your car, and drive at steady speeds on the highway during the beginning of your car's life cycle. If the rings don't burnish your cylinder walls properly, you could have massive amounts of blow by. When you install a new engine, it's important to give it a few seconds of wide open throttle in a higher gear. While new cars have had this routine performed many times before they hit the show room, the mechanics suggested repeating it for the first 1000 miles, and avoiding cruise control to create the optimal seal.

Brakes

Even I know you should avoid hard braking after a new brake job. Conventional wisdom on this point is correct, as the high temperatures can cause glazing on the surface of your pads, which will basically reduce the effectiveness of your braking system. The only exception is racing pads that need to be heated up enough to fade. After a slow cool down, the top layer is removed and you will get better fade resistance throughout the life of your pads. Regular brakes always work better and last longer when you brake slowly and minimally.

Oil

Car pros always recommend changing oil in a new car well before the usual 3000 mile cutoff. In this instance, their myths are partly based on fact. The bearings, lifters and cam shaft all burnish the surfaces they mate to in the first 100 miles of normal driving. It is crucial to do an oil change after this occurs to remove the tiny particles of shaven metal that accumulates. Some initial oil changes have revealed even larger particles such as washers and pieces of rubber. The mechanics say to do the first change between 50 and 100 miles, and follow up with the second before 1500.

Interior

Everyone has the urge to clean their new car repetitiously until at least the new car smell fades. Chemists say that using interior protectants such as Armor All can cause the plastic to leach chemical components onto the surface, raising the risk of age related wear years down the road. Dusting with a static sheet will keep the chemicals at bay, and your interior clean until there is noticeable degradation in the appearance of your plastics. A slightly damp cloth will take care of any dirt or residue. However Scotchgard applied to brand new upholstery can help keep particulates from clinging, making a quick vacuum much more efficient later on.

Sources-

Mitch Justice, the author's brother is an ASE certified mechanic and graduate of Nashville Auto Diesel College. He consulted several peers in agreement on the topics listed.

Popular Mechanics, September 2010 '" "How to Break in a New Car" by Mike Allen