There are plenty of ways to run-in your new car. Some of them are the right way. Degree of difficulty - EasyIt’s a thing of beauty: a brand-new car, shiny and crisp. It makes you want to spend the whole evening walking around it. Pretty soon, the neighbours wander over to congratulate you – and to render advice.

Break it in carefully, one says: “No more than 50 km/h until it has 1 500 kays on the odo.”

“No,” another says. “If you want it to be fast, drive it like you stole it.”

Others recommend synthetic oil, or nitrogen in the tyres, or a mouse-milk oil additive, guaranteed to double fuel economy.

The ritual of running in a new car is part of the body of knowledge we refer to as conventional wisdom. It’s not necessarily wise, and the technology of building a modern car has evolved to the point where a lot of “wisdom” is obsolete. Few cars specify a run-in procedure any more, simply cautioning you to avoid extreme acceleration or extended idling for the first thousand kilometres or so, and there’s little in the way of extra service up front. Some don’t even mandate an oil change until 10 000 km or more. We think your new ride deserves better. Here are a few tips.

Engine cylinder walls
Piston rings don’t rely on their spring tension to seal against the cylinder bores. Instead, combustion gases work their way between the rings and the piston and force the rings outward. During the first few minutes of engine operation, it’s important that the throttle be opened pretty far at lower revs to provide this high pressure. Otherwise, the rings won’t burnish the cylinder walls properly, and the engine will have high volumes of blow-by – which means excessive oil consumption and shortened engine life.

If you’ve ever seen the car jockeys who drive new cars off the end of the production line into the storage lot, or the transporter drivers zipping up and down the car-hauler ramps, you’ll realise that this all-important step has been performed for you many times. If you’re installing a new engine, simply give it a few seconds of wide-open throttle in a high gear. For the first 1 500 km, avoid constant speeds and throttle settings. If you commute in normal stop-and-go traffic, you’ll be fine. I advise against cruise-controlled sojourns across the Karoo.

Bearings
The admonition to keep engine revs low for an extended run-in period stems from the days when bearing and crankshaft manufacturing tolerances were far less rigorous and lubricating oil wasn’t nearly as good. While modern engines are assembled to much the same design clearances, the tolerances are much tighter, meaning the variability is smaller, greatly reducing the possibility of a tight spot. Red-lining a fresh motor is generally a bad idea, but there’s no reason you shouldn’t drive normally. I would, however, avoid topspeed testing, drag racing or towing heavy trailers for the first 1 500 km.

Transmission
The engine run-in procedure also covers the gearbox and the clutch on manualtransmission cars. Most cars with automatic transmissions today are factory-filled with ATF and, supposedly, will never need changing. Some manufacturers are so confident of this that they don’t even have a dipstick or a fill hole. If the specified fluid is a more normal mineral oil, I’d change it and clean the sump after 1 500 km or so. The organic linings on the clutch packs shed a lot of debris, and it generally just turns into sludge that lies in the sump. You don’t want wear metals and sludge to get picked up by the pump and start circulating in the expensive bits.

Oil
I customarily change the oil in a new engine after about 50 km, and again at 1 500 or so. That 50 km-oil, you would think, would look pretty much like fresh oil right out of the bottle. Wrong. It usually looks more like metal-flake paint, iridescent with tiny particles of metal worn off rubbing surfaces inside the new engines. After a few hours of operation, this completely normal phenomenon slows down as the rings, camshaft, lifters and bearings burnish their respective mating surfaces.

Brakes
New brake pads on new brake rotors don’t really require a run-in procedure. The texture deliberately left on the surface of the iron discs will grind down the fresh surface of the pad material within a few kilometres. Even so, refrain from highspeed stops or dragging the brakes for a few hundred kilometres. Racing pads, however, need to be heated up enough to fade and then carefully cooled off, which removes the top layer and provides better fade resistance.

Interior
Avoid the impulse to slather the interior trim with shiny protectants, which can leach the plasticisers out of new vinyl and increase the likelihood of age-related cracks. On the other hand, a generous dousing of Scotchgard on the cloth upholstery and carpets will keep dirt, pollen and mildew from clinging.

Paint
In years past, it was considered a good idea to not wax a fresh paint job for 90 days, to allow the paint to fully cure and any solvents to escape without being trapped under the wax. Modern catalysed clear-coat paint is as hard as it will ever be as soon as it cures, before the car leaves the plant. Applying 3M Paint Protection Film to the leading edge of the painted bodywork will go a long way toward minimising stone-chip damage. Otherwise, a good coat of wax will repel water, atmospheric pollutants and dead bugs.