Although we make every effort to cover our own travel costs, in this case McLaren flew us to Phoenix to drive the 600LT (and the 720S Spider; more on that next week) and provided two nights in a hotel.

I'll admit it: I wasn't sure if I was going to like the McLaren 600LT Spider. I wasn't the biggest fan of the McLaren 570S , the car it's based on—unlike almost everyone else who's driven one , I'd pick an Audi R8 as my daily drivable mid-engined supercar. While the 570S made concessions to practicality, I never gelled with the way it looks, and it had enough electronic foibles that they became one of my overriding memories of my time with the car . But the 600LT makes many fewer compromises in the name of everyday use, and it's all the better for it.

Veteran McLaren watchers will know from just the name that there's something special about this one: in McLaren-speak, LT means "long tail." The first long-tail McLarens—ten F1 GTR race cars and three F1 GT road cars—appeared in 1997, with new bodywork that extended the nose and tail to increase downforce at speed.

More recently, McLaren dusted off the idea with the 675LT, which applied the same ideas of more power, less weight, and more aerodynamic downforce to the 650S supercar. The result was a track-focused adrenaline-delivery device that hit all the right notes with both the journalists that got to drive it and the 500 lucky individuals who were able to buy one before the order book was full. In fact, there was so much pent-up demand for the 675LT that McLaren announced another 500 were coming that would be convertibles. These, too, sold out quickly.

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

Jonathan Gitlin

McLaren

McLaren

McLaren

The success of the 675LTs, both coupé and spider, did not go unnoticed at McLaren's futuristic HQ in the British town of Woking. If more aero, more power, and less weight could inject some much-needed drama into McLaren's Super Series cars, why not use the same approach on the company's Sports Series cars, the entry point to its carbon fiber supercars? As the 650S begat the 675LT, so the 570S evolved into the 600LT, debuting as a hardtop last summer and now as a spider (a name given to sporty horse-drawn roofless buggies in ye olden days).

Once you get past the retina-searing paint, you notice the 600LT is adorned with complicated aerodynamic devices—carbon fiber outgrowths that channel the air and put it to work at speed to squish the car onto the road. It is indeed longer than a 570S by almost three inches, and most of that at the rear, although the bigger front splitter adds some length, too. To my eye, the aero add-ons give the car a much less-benign look than the 570S, particularly at the rear, which is dominated by a large, fixed wing up top and a no-nonsense rear diffuser down below. The revised bodywork generates a useful 220lbs (100kg) of downforce at 155mph, although even on track we were not able to reach sufficient speed to confirm this.

McLaren designed the Sports Series to be a convertible from the ground up, and so the 600LT Spider needed no extra stiffening or additional bracing compared to its coupé sibling. The folding roof mechanism does obviously add a little weight—110lbs/50kg to be precise—but that's OK, because the car still benefits from all that lightweighting. As a result, it brushes the scales 220lbs lighter (100kg) than the 570S Spider Eric drove a few months ago . (The lightest dry weight for a 600LT Spider is 2,859lbs/1,354kg, but with fluids and a full tank of gas, you can expect to be closer to 3,100/1,405kg.)

The importance of weight saving is also obvious from the interior. Here, going nuts with the options list gets you seats prized for their lack of mass, not the number of degrees of power adjustment. You can tell McLaren would have left out the air conditioning if you really wanted it to. Perhaps counterintuitively, wrapping everything in black Alcantara rather than leather really elevates the 600LT's interior over the more pedestrian 570S.

If I had one complaint, it's that the P1-spec lightweight racing seats needled my right side when I was in the driver's seat. I noticed no such problem from the passenger's chair, and I didn't get to try out the super-lightweight one-piece carbon seats (which save 46lbs/21kg) for comparison.

Reducing mass obviously improves a car's power-to-weight ratio; so, too, does increasing power. The 600LT's 3.8L twin-turbo V8 is yet another version of the M838T, which has powered every recent McLaren other than the 4.0L Senna. In this configuration, it delivers 592hp (441kW) at 7,500rpm, with a peak torque output of 457ft-lbs (619Nm) from 5,500-6,500rpm. (It's called the 600LT because it makes 600 metric horsepower.) The wider air intakes help in this regard, as does the raucous, lightweight exhaust system that now exits from a pair of pipes just ahead of the rear wing. And yes, the carbon fiber of that wing has been protected with a heat-resistant ceramic coating, in case you were curious.

Power is sent to the rear wheels by a seven-speed dual clutch SSG transmission that, like the V8, is unique to McLaren. Among its abilities is a "rolling burnout mode:" on a private road or other suitable location, you too can turn a pair of 20-inch Pirelli Trofeo R tires into smoke with just the press of a few buttons. It's an even more pointless special ability than launch control, particularly if you're the one paying for new rubber. But I'll admit I'm downhearted that I did not find time to try it out.

Zero to 62mph (100km/h) takes 2.9 seconds (0-60mph is 2.8). Zero to 124mph (200km/h) takes 8.4 seconds, and the top speed is 202mph (325km/h) with the roof up and 196mph (315km/h) with it down. Fuel economy is rated as 15/18/22 city/combined/highway, which is pretty good for a car like this.

Left to its own devices, the SSG gearbox will pick its own gears with the best of them, but you don't drive a car like this because you want it to pick the gears. Better to take charge of that yourself, via the wheel-mounted paddles. Set the powertrain to Track for the fastest shifts, and you'll want Sport or Track to properly enjoy the engine's bark on up- or downshifts. Yes, it's childish, but a winged, neon supercar is hardly subtle at the best of times, and the added aural character over the more staid 570S is definitely one of the more effective tweaks.

Multiple modes

Likewise, the handling options are Normal, Sport, or Track. As with previous McLarens, you can set these independently of whatever setting you chose for the powertrain. Honestly, I couldn't tell much difference on the finely surfaced roads of Arizona; even in Track, the ride was never particularly harsh and was always well-damped. The car rides slightly lower (-0.3 inches/-8mm) than the 570S, on stiffer front (+13 percent) and rear (+34 percent) springs, and its antiroll bars (+50 percent front, +25 percent rear) are much stiffer. The suspension wishbones and uprights are borrowed from the current Super Series car, the 720S (more on that one this time next week), which also cuts a helpful 22.5lbs from the car's unsprung mass.

Escalating through the handling modes stiffens the twin-valve adaptive dampers at each corner, and it also changes the thresholds for intervention by the car's traction and stability controls. Changing modes doesn't do anything to the steering, however. McLaren is a bit of an outlier in that it's still using electrohydraulic power steering, and the company says it's judged the ratio on the 600LT perfectly. The car is very well weighted, with plenty of feel and feedback coming in from the front wheels (like the rears, clad in 600LT-specific Pirelli Trofeo R tires).

We were able to delve a little deeper into the 600LT's handling on track. Located next to Luke Air Force Base, Arizona Motorsports Park offers a good mix of medium and low-speed corners with a backdrop of F-35As taking off and landing every so often. It proved to be nimble, switching direction willingly and with little fuss even when trail-braking into a hairpin. I was given instructions to use the curbs as much as possible in order to show off the suspension's ability, something more than one of us also tested inadvertently on a particular cattlegrid on the drive there.

Even in Track, the 600LT's electronic safety net (called Proactive Chassis Control) has your back. This was obvious on my final couple of laps when Charlie (the exceedingly affable instructor) poked one more button to enable Dynamic mode. Now the car stopped flattering my driving style and exposed how I needed a more progressive throttle application out of that same hairpin. I imagine my smile would only have grown larger with more time to get to know the car in Dynamic on track, but the demands of airline schedules afforded me only a couple of 20-minute sessions.

The price of all this extra honing over the standard 570S Spider is not inconsiderable. That car starts at $208,000, which sounds like an awful lot but is actually quite competitive with peers like the Porsche 911 Turbo S Cabriolet or the Ferrari Portofino. If you want all the lightweight focus of a 600LT Spider, be prepared to cough up at least $265,500, and it doesn't take too much enthusiasm on the options list to make that first digit a three. If that still sounds tempting, there's good news: unlike the 675LTs, this hardcore McLaren isn't a limited-edition production run, and up to 20 percent of the Sports Series output at Woking could be 600LT models in 2019.