By TONY NG

RUNNING in your new car.

Some fanatics swear by it, others dismiss it as unnecessary.

There's a whole slew of theories in magazines and on websites about this "art" - from changing oil to not tapping your accelerator too hard.

So, what's the gospel truth?

Because of minute imperfections that occur in manufacturing, mechanical components are uneven and these are mated to other parts.

Running in - a process that occurs in the first 1,000 to 1,500km - enables these imperfections to be evened out through beneficial wearing.

A proper run-in can give several benefits.

Besides letting you get comfortable with your new ride, it will also increase the lifespan of your engine and improve its fuel consumption.

If you are buying a car with a manual transmission, a run-in period will also smoothen gear changes, says Mr Shreejit Changaroth, the resident tech guru of Torque, Singapore Press Holdings' monthly motoring magazine and owner of a mechanical- engineering firm.

Says Mr Changaroth: "All the parts used in the car are mechanical bits set to certain tolerances - they need a minimum amount of wear for the parts to fit perfectly."

He drew an analogy between that and wearing new shoes.

"It takes a while before the shoes fit the shape of your feet perfectly and you feel comfortable."

There are two simple rules to observe while running in a car, Mr Changaroth advises.

One, maintain a gentle touch while driving for the first 1,000km.

You should not accelerate or brake suddenly.

Two, as the mileage increases, bring up the revs and vary the throttle.

Let the engine get used to different gears and avoid travelling at a constant speed.

If possible, avoid revving your car above 4,000 rpm.

Self-employed Yew Yee Chong, 28, who has just finished running in his new Volkswagen Tiguan, agrees.

He says he will not go into high revs until the odometer passes the 1,500 km mark .

The one-month-old vehicle is his third ride.

Running in a car is also important for safety.

New cars should be driven carefully for the first few hundred kilometres, as new tyres and brake pads have a longer braking distance and less grip on the roads.

The rule of thumb is to follow what your manufacturer's manual advises.

Volkswagen advises new owners to run in the tyres carefully for the first 500km and, for new brake pads, for the first 200km to 500km.

It also tells owners to apply more pressure on brake pedals to compensate for the slightly reduced braking effect during those distance periods.

But, while Volkswagen recommends an oil change at 15,000km, Mr Yew says he changed the oil at between3,000km and 5,000km. He reasons that "people who love their cars will take care of it".

Engine oil from the run-in period usually have particles in it due to the wearing of the mechanical bits, which is not good for the health of the engine.

The oil filter should get rid of the bits but this is where it is better to err on the side of caution.

Mr Changaroth also recommends doing basic maintenance on the car every fortnight for the first three months.

Some people believe that modern cars arrive with engines already run in but he begs to differ.

Car factories do only diagnostic tests on the engines to make sure they are in working condition, he says.

Due to technological improvements, running in a car today is less crucial now, compared to 20 years ago.

For example, in the past, cars used to require servicing after the first 1,000km but, now, the first servicing is at the 15,000km mark, Mr Changaroth says.

An engine that is not run in won't fall to bits, he assures.

But neither will you enjoy the benefits that come with an engine that has been run in.

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