n00dleboy

Breaking in a New Vehicle
by Jim Kerr

I am asked this question at least a dozen times a week: "how should I drive my new vehicle to break it in?" Breaking in of a new vehicle is a straightforward process but there are many stories told about how to best do this. There is some truth in many of the stories but to separate fact from fiction, we should look at why we need to break a vehicle in.

A good friend often jokes that there is no such thing as "breaking in" a new vehicle - it is just the start of "wearing it out!" There is a little truth here too. The process of breaking in a vehicle means driving it so that parts can wear into each other. Usually, people think the engine is the only part that needs any break in period, but transmissions and drive axles also can benefit from a break in. So how should I drive the vehicle?

Start by avoiding heavy loads on the drivetrain. Full throttle starts, towing trailers, and loading the vehicle with heavy loads place extra force on all moving parts in the drivetrain. When parts are manufactured, their surfaces may look smooth but under magnification, we can see many "hills and valleys". Lubricating oil forms a thin film that separates moving parts so they do not touch. If there is a loss of lubrication or a heavy load placed on the parts, the high spots (hills) may push through the oil film and touch the other part. This causes wear.

The break in process allows the highest of these hills on the parts to wear down under light load so they do not damage other parts. As the parts move, they are polished so that there is less chance on high spots penetrating the oil film when a load is placed on the vehicle.

The manufacturing processes used today are light years ahead of vehicles from the 1960's and 70's. Component finish is better, internal clearances are closer, parts tolerances are more accurate, and materials are better quality. The thousands of miles needed to break in an older vehicle are no longer needed. Instead, it is the first few hours of operation that are the most important. By the time a driver has driven a few hundred kilometres, the vehicle is ready for regular driving.

When starting a new vehicle, engines should not be idled for long periods of time. Oil pressure is lower at idle speed and parts that depend upon splash lubrication may not receive enough oil to prevent high spots from pushing through. Full throttle operation should also be avoided. It places heavy loads on components and high spots can score other components, accelerating the wear. This doesn't mean you need to baby the vehicle.

Drive the vehicle as if you were trying to achieve good fuel economy. Light to medium throttle acceleration is preferred, and keep the engine rpm's in the bottom half of the rpm range. On many engines, this would be below about 3000 rpm for the first few hours. Occasional three-quarter throttle acceleration is fine, as the increased gas pressure in the combustion chamber helps the rings to seal.

Avoid "lugging" the engine. Driving in too high a gear at low speeds makes the engine work harder. It is better to have it running a little faster with less throttle than too low an rpm with more throttle. Modern engines don't need to be driven at slow speeds. Keep up with traffic and drive the speed limit. I wouldn't recommend towing a trailer with a brand new vehicle, but it is done sometimes and the vehicles seem to last well.

Some say that drivers should vary vehicle speeds during the break in period, driving only a few kilometres at one speed. This isn't necessary. If you are going to be driving on the highway, backing off the throttle every few kilometres and letting the vehicle decelerate for a few seconds will pull extra lubrication into the upper engine cylinders and intake valves.

Breaking in a new vehicle isn't a tedious or time consuming process. Drive it normally and with care for the first few hours and it should be ready for many more kilometres ahead

AEMcivic

So technically we only need to go a few hours for things to break in? I think I've heard that the break in period is about 500 miles. According to this we could go about 100 miles and things would be ok. Either way, you should be nice to your car all the time.
BTW, Nice post.

CivicVTec

iTrader: (9)

i heard from 800-1000 miles

blouisgod

iTrader: (14)

1000 miles under 4000 rpms. Hours[IMG]i/expressions/laugh2.gif[/IMG][IMG]i/expressions/laugh2.gif[/IMG]

RedDragon333

iTrader: (4)

this is what I heard

nytejade

I actually heard once that your car doesn't completely break in until 10k miles. Who knows how much truth there was too that. I heard it on IRC.

Boosted2k2

iTrader: (3)

My dealer told me 500 miles under 70mph = 3000 rpm

Boosted2k2

iTrader: (3)

I heard that, but in the sense that the ECU controls the break in. I think it was in relation to the Si though over a 5000 mile period.[IMG]i/expressions/face-icon-small-confused.gif[/IMG]

dragoon

iTrader: (2)

i go by the manual. it says 600 miles.

Mbow

I was about to post that...why all the confusion when the owner's manual tells you how to break-in the engine...

OOoooPPssS...My Bad, I forgot that no one reads the owner's manual.

SoNiCcIvIc

Couldn't have said it better.

I was told not to go over 70-75mph on the freeway, too. Guess because the RPMs would be kinda "high" for break in as it would be over half the RPM range.

ASIANPRIDE

I drove it home from Calgary (bought it) to Edmonton (where I live)....they said..to varry my acceleration.....soooo
But I drove it like a baby for around 5000k...now...I drive it like I stole it..haha kinda..[IMG]i/expressions/demon.gif[/IMG]

Blown

Are you saying that the intake was a bad gift? I know when I had it, I always wanted to hear it.

ASIANPRIDE

As if...hahaha...I don't drive my car...like a baby nemore...I rip it up now..that you gave me that intake...for xmas....hence...drive it like you stole it..haha...

AR

iTrader: (2)

when i left the dealership, the dealer told me their really is no need for actual "breaking in" the car. he claimed their was a special oil in the car from honda that breaks in the car for you. i dont know how much of this is true, but i didnt listen to him. i took it easy on my car for like 1000 + miles.

slammed

F**K IT..........Drive it like you stole it!!!!!!![IMG]i/expressions/laugh2.gif[/IMG][IMG]i/expressions/laugh2.gif[/IMG][IMG]i/expressions/laugh2.gif[/IMG][IMG]i/expressions/laugh2.gif[/IMG][IMG]i/expressions/laugh2.gif[/IMG]