The McLaren 600LT Spider is a track terror, but the topless 720S is a sweeter treat

Ian Digman, McLaren’s head of product management, said one of the most insightful things I’ve ever heard anyone say at launch event. “McLaren,” he told journalists gathered for the unveiling of the 600LT Spider and 720 Spider, “sees itself not in a power war, but in a weight war with its competition.”

Amen to that.

Of course, McLaren, the slick boutique speed emporium with an HQ that looks like something a Bond villain might inhabit, never wants for power. The 600LT Spider makes 592 horsepower, while the 720S Spider puts down 710. If you need more than that, you need to visit a therapist, not a McLaren dealer.

No, reducing curb weight is going to define the future of automotive advancement as engineers work ever harder to extract more from less. And it’s the claimed weight figures for McLaren’s new carbon-fiber convertible crumpets that really grab you as you scan the spec sheet. The 600LT weighs just 2859 pounds dry; the fully bananas 720 comes in at 2937.  Okay, yes, add a few hundred for fuel, oil, and a driver, but 710 horsepower! The McLaren 720S coupe can sprint from zero to 60 mph in around 2.8 seconds. McLaren says the Spider is just as quick, and we believe it. We’re told the 600LT should do the deed in 2.9.

That’s a lot of breathless yammering about power and weight and acceleration. And if you haven’t kept up with the product tornado coming out of McLaren these days, you may wonder just what the 600LT and 720S coupe are and why anyone might cut off their lovely roofs. It’s all part of McLaren’s plan, called Track25, to ensure it remains an independent automaker for the foreseeable future. It calls for churning out a dizzying 18 new models by 2024, and not one of them, we’re assured, will be an SUV. McLaren wants to build cars at the healthy rate of 6000 a year, about 1200 more than it built last year.

While the plan includes several hybrids and perhaps even EVs, it also calls for a decent number of convertibles. Drop-tops typically account for about half of all screaming mid-engine doorstops, a market that includes the Ferrari 488 and Lamborghini Huracan, among others. If you don’t offer a convertible, you aren’t in the game.

The 600LT is a faster, sportier version of the entry-level 570 two-seater, while the 720 sits at the top of the line before you get into the truly special limited-edition Senna and Speedtail. The 600LT Spider starts at $256,500, the 720 at $315,000.

Although just as fast as the 720, the 600LT—for “long tail”—costs a lot less because it makes due with less power and it lacks Proactive Chassis Control II, McLaren’s fancy hydraulically controlled suspension. The LT designations identifies it as a more track-oriented car about three inches longer than the 570, an aerodynamic enhancement that improves downforce. With the 570’s lowered suspension, standard carbon-ceramic brakes, and track-spec Pirelli PZero Trofeo R tires, the crew in Woking clearly designed this car for people who want to flog their McLaren.

The 600LT Spider weighs about 220 pounds less than the 570 Spider, something McLaren accomplished by giving the car thinner seats and windscreen, using titanium bolts to secure the lighter wheels, and a shorter top-exit exhaust. All told, 23 percent of the parts that make up the 600LT are different from those on the 570.

The 600LT is an impressive car, but the 720 shimmers like a drop of mercury in comparison. McLaren threw almost everything it knows about going fast into the 720, saving only a few tricks for the flagship Senna and Speedtail models. Variable aerodynamic elements. Multiple driving modes. Hydraulically linked, continuously variable shock absorbers that eliminate the need (and weight) of sway bars. The system reacts to driver input, the car’s movements, and the road surface to provide almost telekinetic handling and reasonable comfort. Oh, and the the high-res multicolor display uses a tiny electric motor to somersault at the touch of a button to reveal a simplified F1-style tachometer.

McLaren designed the carbon-fiber tub, called the Monocage II-S, with an eye toward improving visibility from the cockpit. It features the thinnest of A-pillars, and glass panels in the rear buttresses to eliminate what would be a wicked blind spot. If you want the full-on F-16 canopy experience, get the electrochromic glass roof that dims at the push of a button.

McLaren feels no obligation to show off the twin-turbo V-8 engine in either one of these cars, although you just just glimpse it behind a mesh screen. That gave the designers and engineers a somewhat freer hand creating the retracting roof mechanism. The 600’s takes just 15 seconds to fold itself behind the seats. The 720’s more elaborate one-piece roof uses eight motors to slide the roof panel rearward and stow it beneath a hatch that serves as a shallow cargo compartment when the roof is up. It sits just above the 4.0-liter V-8 and uses elaborate insulation to prevent anything you stash in there.

The 600LT is a track weasel that spits flames from its pipes and welcomes you to the edge of its envelope (and your nerves) with a fearsome bawl from the V-8 and gluey grip from those Trofeo Rs, one of the stickiest street-legal meats on the market. Compared to the 570 and the 720, it is more tense and, frankly, louder inside, owing in part to a shortage of carpet. It’s nevertheless just as easy and predictable to drive, even with the stability assistance turned way down. The ride is such that you can tell if the guy who last tarred the road seams was having a good day or a bad one, but it’s surprisingly supple over the larger holes considering it lacks the 720’s wonder-widget suspension. You could live with this car every day, though the shape of the door opening and the low-flying windshield frame make emerging from it a battle against gravity.

Why pay $60,000 more for the 720? The 600LT, with its aero tack-ons and that black slash of scoop on the side, looks like it’s trying to be something. The 720 really is something, with lines so elegantly styled and a driving experience so meticulously polished that only the rankest cynic wouldn’t be impressed. Yes, the 720 is bigger and heavier, but you’re grateful for it when you realize how much easier it is getting in and out of the car. And out on the road, you’d never know it was bigger. The suspension sashays over the crud that the 600LT telegraphs but is completely unfazed by even the hairiest of pavement macaroni.

Put the top down in either car and you can carry on a conversation, provided you use your outdoor voice. The retractable rear glass motors up or down to provide even more isolation. And the center console electronics are nearly identical in their own quirky way.

One word of caution, tough: You don’t want to nail the throttle unless the road ahead is long, straight and clear, because the boost comes on almost instantaneously. The horizon arrives with just a few upshifts. And that brings to mind the best reason why I’d give the nod to the 720. Both cars are almost absurdly quick, but in the 600LT, it always feels like you’re working for it. The 720 is effortless.