Posts Tagged ‘Performance’

Listen to This!

Thought i’d toss up this video clip of the Jaguar XKR singing for my camera. This could be the best sound to ever come out of a tailpipe. Dont turn it up too loud though, you might blow your speakers.

Porsche Cayman R

Fast and sexy and very very green! Porsche’s most hardcore Cayman heads North for a test-drive.

Breaking It In

Breaking Engine In

Engine break-in procedures vary from vehicle to vehicle, though the logic behind them is virtually universal. The break-in period for most cars is relatively painless— unless you can’t romp on your new Corvette for 805 kilometers!

Many folks remember their first baseball glove and the excitement of breaking it in for a long life of playing catch, softball and the like.

But how? Was glove oil the answer? What about tying a ball into the glove and leaving it in the sun? Under a mattress? In a dark corner? Should it be rubbed with shaving cream? Maybe it was best to just get out and start playing catch.

Like a baseball glove, new-car engine break-in procedures are often a bit of a grey area. Each manufacturer has a different break-in recommendation for their engines, some being more complicated and extensive than others. In general, not following the break-in procedures to the letter won’t cause serious problems—though a properly broken-in engine is more likely to have a long and enjoyable life.

Your average affordable sedan probably has a break-in recommendation similar to that of the Chevrolet Cobalt. GM engineers say there’s no elaborate procedure to follow, but that the vehicle will perform better if drivers follow some simple rules for the first 805 kilometres. These include not travelling at constant speeds, now downshifting, and not making full-throttle starts.

Why the extra initial care? It’s all about ensuring uniform wear occurs between components within the engine. Engine internals work in contact with one another under very tight tolerances– so the surface formed between them is very important.

For instance, the metal piston rings are always in contact with the cylinder wall. A proper surface between the two is vital for engine compression, which ultimately dictates performance and fuel efficiency. Changing engine speed and load encourages the piston rings to move slightly, which helps creates a more uniform wear surface between the ring and cylinder wall. That’s exactly why many break in procedures recommend against using cruise control or a constant engine speed during break in.

GM says a relatively high rate of wear occurs during break-in compared to the rest of the vehicle’s life. Through testing, engineers have determined that most of this wear has occurred by 805 kilometers in a standard engine– after which point speed and load can be gradually increased.

High performance engines like that in the Chevrolet Corvette are subjected to more heat, tighter tolerances and higher stresses than a standard engine—and the break in procedure is more complicated, too. The Corvette manual outlines a break-in of over 2,400 kilometres, advising that long-run performance will be improved if procedures are followed.

For the first 805 km, things are painful. There’s no full throttle, no exceeding of 4,000 RPM and no use of cruise control. Owners are also advised not to let the engine ‘lug’ by allowing it to pull the car from very low revs. Finally, the Corvette manual suggests owners watch oil consumption and avoid competitive driving for the first 2414 kilometres.
Mercedes-Benz knows a thing or two about performance engines as well. Their Manager of Technical Service, Literature and ISO is Sylvain Gilbert. He explains what goes on inside an engine during break in.

“Modern manufacturing technologies can precisely cut, polish and hone materials at exact dimensions, with tight tolerances. However, at a microscopic level, metal surfaces that appear perfectly smooth can actually still be rough. During break-in, the peaks of the microscopically rough metal surface get shaved off or flushed away, so the surfaces smooth out and glide with less resistance”.

The standard Mercedes-Benz break-in for gas and diesel engines recommends driving at varying engine speeds for 1,500 kilometres while keeping the revs below 4,000. After this point, customers can gradually increase engine speed and load to the permissible maximum.

When it comes to breaking in the brand’s high-performance AMG engines, Gilbert says procedures are virtually the same– but with a few additional stipulations. These include keeping the vehicle speed below 140 km/h, and ensuring the engine is at operating temperature before being driven at higher RPMs.

The specially-designed AMG engines take higher loads into account, using special materials and parts to handle additional stresses of performance driving.

“Optimal engine performance and fuel consumption are only reached after the break-in period is complete. Power actually varies a little over engine life—it actually raises within the first few hundred kilometres” Gilbert added.

Not sure the proper break-in procedure for your vehicle? Like so many other questions relating to your new ride, the answer is in your owner’s manual.