They say motor racing makes better road cars.

That may have been the case 50 years ago when Ferrari battled Fords for line honours and showroom bragging rights, but it’s not true today.

These days road car development outpaces their race track cousins; Formula One adopted hybrid technology in 2009 -- 12 years after the first Toyota Prius.

Many V8 Supercars have no relationship with their showroom equivalents -- have you seen a rear-drive V8-powered Nissan Altima or Volvo S60 sedan on the road lately?

That doesn’t mean motorsport is not full of talented people, it’s just that their expertise is getting cars to perform at their maximum for just long enough to qualify fastest and win a race. Who cares if the cars fall in a heap on the way back to the pits?

Road cars must start every time, handle the daily grind in extreme temperatures, and be driven by people who may not have mechanical sympathy. The cars themselves must be built in the thousands with perfect quality time after time.

In effect they are two completely different skills sets, which is why we’re watching with interest how McLaren’s tilt at becoming a supercar maker is going.

It launched a $500,000 supercar four years ago and has now added two more affordable models to its range -- with the familiar pitch of trying to beat Porsche.

If first impressions are a guide, McLaren is a long way off getting close to the established sports car brands, let alone overtaking them.

I probably shouldn’t be surprised that the air-conditioning didn’t work in the $325,000 McLaren 540C.

The British-based F1 firm failed to finish 14 Grands Prix last year, hasn’t won a driver’s title since 2008 and hasn’t won the F1 constructors championship since 1998 - the year after the Prius was invented.

Which is why I probably shouldn’t be surprised that the air-conditioning didn’t work in the $325,000 McLaren 540C we tested in Australia for the first time this week.

And why the air-conditioning in the $379,000 McLaren 570S whistled loudly, like an old Valiant being driven down the Hume Highway with its windows open.

McLaren said these cars were “demo” models and getting a bit long in the tooth, having been flown around the world for preview drives.

But they were the same cars being tested by prospective buyers in Australia last week, so presumably McLaren was putting its best foot forward.

On the plus side, McLaren seems to know how to make an engine and transmission with supercar pedigree.

The twin turbo 3.8-litre V8 borrowed from the flagship model (but detuned to 397kW/540Nm in the 540C and 419kW/600Nm in the 570S) has epic levels of grunt.

Matched to a seven-speed twin-clutch auto, it slams through the gears seamlessly. The shove of torque is epic even with a light touch of the throttle.

Despite the different claim for power outputs, I dare anyone to pick the difference. The 0 to 100kmh time is 3.5 seconds for the 540C and 3.4 seconds for 570S - neither are slow.

The steering is linear and superbly weighted in feel; you can plant the car exactly where you want to in a corner.

But whatever you do, just don’t hit a bump.

Both the new McLarens (which share a new carbon fibre chassis tub but have less sophisticated suspension than the flagship 650S) banged over bumps whether they were in comfort or sport mode.

Hitting a lane marker sounded like someone was under the car hitting it with a rubber mallet.

Here’s hoping McLaren fits the better suspension from the 650S to iron out the bumps and the noises. (Helpfully, McLaren had a 650S on hand for comparison purposes.)

In the meantime some sports-car enthusiasts are probably scoffing, accusing me of being too harsh.

Porsche 911s might be more common, but we've never experienced in a Porsche the basic faults that these McLarens had.

But here’s the thing: it was McLaren that said it wanted to build a Porsche beater. It’s certainly charging more for a regular 911 with the 540C. And the 570S is dearer than a Porsche 911 Turbo.

Porsche 911s might be more common, but we've never experienced in a Porsche the basic faults that these McLarens had.

McLaren has a long way to go before it can outdo the overall refinement, dependability and drive-ability of a Porsche. Or a Lamborghini. Or a Ferrari.