Comparison Test Review: 2006 Chevrolet Corvette vs. 2007 Ford Mustang Shelby GT500

Heavy Pedal: With 500 horsepower, a dynamo Shelby Mustang goes after a very big fish.
BY LARRY WEBSTER
PHOTOGRAPHY BY JEFFREY G. RUSSELL
July 2006
as posted on caranddriver.com

A lot of people think the Ford Mustang and Chevy Camaro duel has been the most exciting rivalry in the history of cars. Others think of it as the automotive equivalent of a People magazine cover story on Jessica Simpson — it’s a worn-out story, but you give it a look anyway.

By now you know that GM no longer makes Camaros, so our ritual is in limbo. (The Camaro’s obvious stand-in, the Aussie-born Pontiac GTO, is about to join the Oldsmobile lineup on the discontinued heap.) But Ford has not called it quits in the muscle-car department and has in fact produced the 2007 Shelby GT500, which is not only the most powerful Mustang ever made — 500 horsepower — but also the most expensive at $41,950, including destination. So without a Camaro, the Corvette, which lists at $44,490 and comes packed with 400 horsepower, becomes the obvious crosstown challenger.

Actually, the Mustang Cobra R was the most expensive at $54,995 - Joe

A major difference between this Ford and Chevy is that the Mustang has a pair of back seats and the Corvette doesn’t. The similarities are many and important: Both have front-mounted V-8s, rear-wheel drive, and Motown reputations a quarter-mile long. Plus, their base prices are close.

For this comparison, we wrangled an early-build GT500 from Ford. We’re guessing that options such as satellite radio, an in-dash CD changer, and a 10-speaker sound system will add about three grand to that base price.

On the other hand, the Corvette is a known quantity: It’s a great sports car at a great price. A two-time 10Best winner since the C6 version was introduced in 2004, the Vette is a fantastic performer that can outrun cars that cost tens of thousands more dollars.

We requested a no-options test vehicle but nonetheless wound up with a loaded $56,070 Corvette — it came with a navigation system, polished aluminum wheels, heated seats, satellite radio, a $750 transparent roof, and the $1695 Z51 Performance package. Only the Z51 package alters the Vette’s performance, with its stiffer suspension, larger brakes, and revised gear ratios. So a Vette with the Z51 package that performs like the one we’ve tested here can be had for $46,185.

In addition to the GT500’s as-tested price advantage — it’s more than 10 grand less than the Vette, so in the price category it was awarded 20 points to the Corvette’s 15 — the Ford also prevailed in the back-seat category, earning five points to the Vette’s goose egg. So before a wheel was turned, the Vette was burdened by a 10-point disadvantage.

As always we put both cars through our battery of performance tests. We also spent a day lapping the 2.0-mile Grattan Raceway, a hilly road course that’s about 120 miles northwest of our Ann Arbor headquarters. So can the GT500 really hang with the Corvette?

2007 Ford Mustang Shelby GT500
Second Place: Heavy Pedal

The GT500 is at its best on the boulevard, where its decent ride and comfortable interior make it a great place to hang out in between heavy dips into its swollen torque curve.

Rated at a full 500 ponies, the supercharged 5.4-liter DOHC V-8 under its striped hood responds immediately and strongly at any rpm. It feels more responsive at lower revs than the Corvette’s 6.0-liter V-8, which is itself hardly a slouch in the torque department. And if you like supercharger whine, you’ll love the GT500’s soundtrack, but you’d better love it because you can almost always hear the blower.

However, when it comes to pure performance, the GT500 has trouble hanging with the Vette. It prevailed in only two tests, beating the Vette in the lane change by 1.3 mph and outgunning the Chevy in the 50-to-70-mph top-gear acceleration run — 8.8 seconds versus 9.1.

The major reason is the GT500’s weight and how it is distributed. The hardware needed to turn the 5.4-liter DOHC V-8 into a 500-hp monster makes for a long and massive list. There’s the supercharger with its drive pulleys, the intercooler with its pump and water lines. Even the 5.4-liter heavy-duty block weighs more than the 4.6-liter assembly in the Mustang GT. All told, these parts add about 150 pounds to the car — most of it up in the nose. Combine those extra pounds with the GT500’s large brakes, 19-inch wheels and tires, and six-speed transmission, and the result is a porky 3896-pound Mustang.

That adds up to 321 more pounds than the last Mustang GT we tested and a more forward weight bias, degrading from 52.5/47.5 percent to 57.7/42.3 percent.

The Vette is not only 616 pounds lighter but also splits its weight 51.9/48.1 percent front to rear. That more even distribution means more traction off the line, stronger braking, and better handling balance.

At the test track, physics would not be denied. Despite being on tires similar to the Corvette’s in size and specification, the GT500 achieved only 0.90 g on the skidpad, whereas the Vette pulled 0.95 g.

During our brake tests, the GT500 nose-dived dramatically but stopped only a little worse than the Corvette. In our usual 70-mph stop, it needed 172 feet. In a much more punishing 120-mph stop, the GT500 came to a halt in 485 feet. The Vette edged it at 161 and 462 feet, respectively.

What surprised us, however, was the GT500’s loss in the acceleration runs. Its 100-hp advantage should have been enough to leave the Vette in a cloud of rubber dust. The GT500 also has a useful launch-control system that’s part of the standard traction control. To get a nearly perfect hole shot, all you have to do is rev the engine to 3200 rpm, dump the clutch, and floor it. The system automatically modulates engine power to make the driver look like Kenny Bernstein. With it, we hit 60 mph in 4.6 seconds

But we were able to go even quicker without it, thanks to the terrifically tractable engine that makes it easy to keep the tires hooked up. Moreover, the Shelby has a programmable shift light and audible chirp to free your eyes from monitoring the 6000-rpm redline on the tach.

Under full human control, we shaved 0.1 second from the 60-mph sprint, lowering it to 4.5 seconds. The quarter-mile required only 12.9 seconds at 112 mph, 150 mph came in 30.3 seconds, and an electronic tether limited top speed to 155 mph.

Although those are terrific numbers, they don’t seem quick enough for a 500-hp car. Sure it weighs a lot, but the last SVT Mustang Cobra we tested [“Rotary Revival,” C/D, April 2003] posted the same quarter-mile time and speed despite a 20-percent-worse power-to-weight ratio (110 fewer horses, 216 fewer pounds). And the BMW M6 tested in this issue [see page 68], which is also rated at 500 horsepower and weighs 12 more pounds than the GT500, ran the quarter in 12.4 seconds at 121 mph. Ford says that its own quarter-mile tests are 0.1 or 0.2 second quicker with 115-mph trap speeds. The 500-hp figure was obtained using the latest SAE-certified test protocol, so it’s unlikely that the GT500 isn’t delivering the promised ponies. Maybe we were off that day.

In any case, the fiberglass wonder from Chevy ripped to 60 mph in 4.3 seconds and through the quarter in 12.8 seconds at 113 mph. It was also 3.5 seconds quicker to 150, which is hardly surprising given the Corvette’s sleeker shape and smaller frontal area.

Despite the Ford’s disappointing straight-line acceleration, the GT500 happily bounded around Grattan for several laps. Thanks to its reassuring understeer, the GT500 was rock solid at high speed, confidently carving through the faster white-knuckle parts of the track, with the back end always staying in line. The brakes were also strong, showing hardly any fade, even when slowing from about 130 mph into Turn One. In the slower corners, however, the nose tended to plow too much, making it difficult to apply the power early for a strong exit.

Our best time was 1:33.30, about three seconds slower than the Vette, and it’s hard to forget the GT500’s extra poundage. One tester commented, “I’m always aware of the high center of gravity compared with the Vette’s, and the GT500 really bounds and bobs. But I could spend a day lapping this car and never get bored.”

Astute readers might remember that we lapped Grattan in a Dodge Charger SRT8 in 1:32.65 [“Bahn Burners, Episode 39,” January 2006]. But it had rained hard the night before we ran the GT500 and Corvette, and we’d be willing to bet our own dough that the GT500 would be faster than the Charger if we tested both on the same day.

On the road, the GT500 settles nicely into a relaxed cruise. At posted speeds, its behavior is not at all hot roddish, and the ride is quite subtle for a car festooned with racing stripes. Like the original GT500, the ’07 car feels more like a competent all-arounder than an all-out speed machine. It’s refined and fairly quiet, and the steering has a natural weight to it. The seats are too flat for track use but are fine for long trips. If the clutch effort weren’t so pronounced, the GT500 could be a daily driver.

And it’s always ready for those unexpected stoplight duels with its reliable launch control and light, positive, and accurate shifter.

In the end, we wish this GT500 had more horses to go with its lofty price. The last SVT Cobra only cost $35,000 and was just as quick. We also couldn’t stop thinking about a one-off project Mustang we tested in February 2000, the Ford-built, 3587-pound FR500. With a naturally aspirated 415-hp V-8, it was as fast as this GT500, it felt a whole lot less ponderous, and we loved it. We expected the GT500 to mirror it. It’s close, but it’s still a few hundred pounds away. As four-seaters go, the GT500 is the best bang for your buck around, but for pure performance at the price, there’s a better alternative.

2006 Chevrolet Corvette
First Place: Heavy Pedal

That other choice is, of course, the Corvette. Since the C6 version appeared in 2004, we’ve heaped volumes of praise on it, and we’re running out of ways to say that it is arguably the best sports car for the money, period.

As quick as this Vette was (0 to 60 in 4.3 seconds and the quarter in 12.8 at 113 mph), we’ve tested other examples that have gone faster. The Vette we featured in December 2004 got to 60 mph in 4.1 seconds and turned the quarter in 12.6 at 114 mph. The one on these pages, though, was practically brand-new and had only 700 miles on the odo.

Although the engine was a little green, the chassis felt terrific. At Grattan, the same track where a ferocious Z06 Vette scared us silly, the standard model was “composed, forgiving, and easy to place,” according to one driver.

The Corvette is not afflicted with the prominent understeer of the GT500, and you can do things with the Vette that few street cars can equal. For example, in the slow-speed corners where you need to rotate the car and then get back on the gas hard, the Corvette will easily pirouette around its nose with a touch of trail braking. This maneuver is quite easy to perform, and it got the car through those slow corners much sooner than the GT500.

That willingness to rotate means the driver has to be on his or her toes in the high-speed corners, where sloppy throttle work can send the tail sliding out. We got overly aggressive with the throttle twice in a 90-mph right-hander, and the tail broke rank. Usually, that’s a guaranteed moment of panic, but the Vette is so tolerant that we simply countersteered a little and sailed right on through.

Although we also thought that the fade-free brakes were easy to modulate and above reproach, we did find a few other things to complain about. One is the transmission, which required a patient hand to accurately perform the second-to-third-gear upshift. The test drivers missed it repeatedly, and the stubby gearshift rod went into some nether land in the shift pattern that felt as if it were in gear but was actually in neutral. Both cars use the Tremec T56 design, but the GT500’s shorter, more direct shift linkage works a lot better.

And the Corvette seats, in a word, stink. They offer zero lateral support, so even though the driver can lock into place with the seatbelt, he or she winds up bracing a leg against the door and tranny tunnel. The seats feel flimsy, too, and the leather is so slippery the driver is constantly sliding into an inadvertent slouch.

While we’re in bitch mode, the variable-assist steering system could also use some work. On the track, the effort is fine, but on the road it feels artificially heavy and won’t win any prizes for being communicative. It’s not awful, but the GT500’s is better.

Otherwise, the Vette flows down public roads with a grace you wouldn’t expect after experiencing its abilities around the Grattan track. The clutch effort is light, the gauges are easy to read, and the interior is relatively quiet.

And although the Corvette doesn’t have back seats and is 13.0 inches shorter than the Mustang, it does have the largest and most practical luggage compartment of any two-seater on the planet. Fuel economy is clearly not a priority with these cars, but the Corvette does well on that score as well, when driven with some restraint.

In other words, we wouldn’t hesitate to drive this car daily, and it won this duel handily, topping the GT500’s score by 20 points.


Click here for images and a slide show of both cars used in the story.