Three for the Road: Premium Roadsters
June 13, 2007 - Story and photos by John LeBlanc
 
Let’s take a moment, bow our heads and give thanks to Mazda for introducing the 1989 Miata. After years of putting up with half-measure targa panels, slit-like sunroofs and leaky t-tops in other so-called roadsters, Mazda’s convertible sports car reminded driving enthusiasts what fun a truly open-top car for two could be.
 
If not single handedly reviving the roadster genre, the Miata’s success did prod other automakers to join the roadster rush. One that responded—although belatedly—was Audi, with its 1999 two-seat roadster version of the TT Coupe 2+2 that debuted a year earlier.
 
That first TT was fawned over for its outré looks; becoming a design icon in the process. But its wooden driving characteristics had hardcore enthusiasts shopping elsewhere. With its new, second generation 2007 TT Roadster, Audi argues it’s more of a driving tool, ready to take on its traditional Teutonic rivals. Here to contest that assertion is BMW’s evolution of their original Z3 roadster—the Z4, and Porsche’s roadster with a boxer-engine—the Boxster.
 
Previous driving experience with the coupe versions of the new TT suggested the lighter, front-wheel-drive TT 2.0-litre turbocharged four-cylinder model was the driver’s car over the heavier, all-wheel-drive 3.2-litre V6 TT. Even with the formidable S tronic dual clutch transmission as standard kit, the 2.0 model starts at $53,600—$10,000 less than the 3.2 with a six-speed manual.

Price wise, this is Audi's David versus BMW and Porsche's twin Goliaths.
 
The question is, how does Audi’s second kick-at-the-roadster-can measure up out on the roads with its main two German rivals?
 
THIRD PLACE: 2007 BMW Z4 3.0si 6M - To match the performance of the 2.0 S tronic TT Roadster ($60,000 as tested with Premium, Audio Packages and 18-inch rims), forget about the $53,900 base model Z4 3.0i. Its 215 hp inline-six cylinder is over a half second slower from naught to 100 km/h than the four-cylinder Audi at 6.6 seconds.
 
Sorry. One needs to pop for the Z4 3.0si to equal the Audi in a straight line jaunt . That lowercase 's' adds 40 hp and $7,000 to the Z4. With Sport and Premium Packages, the test BMW came to $66,600.
 
A turbine smooth mill with power throughout its rev range, any BMW inline-six is a beautiful thing. Even if it can’t match the immediacy of the Audi’s dual-clutch setup, the Z4’s six-speed manual transmission has short precise throws with a well-oiled, mechanical feel. (A six-speed automatic with steering wheel mounted paddle-shifters is a $1,700 option.)
 
With near perfect front/rear weight distribution, the rear-drive Z4 is balanced in corners where the nose-heavy Audi will eventually lose grip at the front end. Except when the pavement’s less than perfect…
 
That's when the Z4’s unforgiving Sport Package—with its 15-mm lower suspension and 18-inch rubber—consistently tosses the tightly wound Z4 off course, reducing much confidence from the driver’s seat.
 
It may excel on a smooth racetrack, but over the bumps, off-camber turns and cracked public roads on the Ottawa-Mt. Tremblant-Montreal test route, the BMW is the slowest roadster here.


 
TIN-TOP ALTERNATIVE: 2007 BMW M Coupe $68,900
 
WHY BUY?: The way the Z4's engine engages with the slick stick is worth the price of admission alone. But as a point-A to point-B road weapon, there are better roadster choices. Such as...
 
SECOND PLACE: 2008 Audi TT Roadster 2.0 TFSI S tronic - It has the smallest engine with the least power, driven through the front wheels only and accessed by (of all things) a slushbox. As such, the new TT Roadster seemed destined to be the same driving wallflower as the original.

But hang on to your string-back gloves. The new TT is a willing dance partner on any twisty road.
 
The TT’s 200 hp turbo four is seamlessly matched to the dual-clutch transmission. Both deliver rapid responses that are surreal compared to the BMW or Porsche. Even torque steer—the bane of most high-powered front-drive cars—has been extensively mitigated. And its ride doesn’t beat you up like the BMW.
 
After the Z4, the TT feels so much more nimble. But where the TT still falls behind its rivals here is at the tiller. The weight is good, but there’s still a sense of distance from the road that the BMW and Porsche don’t deny the driver.
 
Further than the efficient drivetrain, the key to the TT’s blossoming as a driver’s car is the car's part-aluminum space frame. It allows the TT to be the lightest car here; even lighter than the Volkswagen GTI it’s based on.


 
TIN-TOP ALTERNATIVE: 2007 Audi TT Coupe 2.0 TFSI S tronic $50,600
 
WHY BUY?: The Audi is the all-around athlete of this trio. Beyond the TT's newfound driving dynamics, it comes with the most standard equipment, most luxurious interior and the best fuel economy as well.
 
FIRST PLACE: 2007 Porsche Boxster S 6M - Whereas the TT and Z4 are born from more plebian cars—the GTI and 3 Series, respectively—you can find plenty of big brother, rear-engine 911 Carrera in the rear-drive, mid-engine Boxster.
 
For ’07 both Boxster models share poerplants with Porsche’s hardtop Boxster; aka Cayman. A 245 hp 2.7-litre flat-six is in the base Boxster. The as tested Boxster S is powered by a 295 hp 3.4-litre six that until five years was essentially the same unit found in the 911.
 
Realistically, the $63,600 entry level Boxster is a closer match to the BMW and Audi in price and performance. You can decide whether the additional cog in the S model’s six-speed manual and the extra urge are worth the $13,700 price hike. (A six-speed automatic comes only with a Preferred Package, priced $6,790-$7,100 depending on the Boxster.)
 
Neither the TT nor Z4 can match the regular or Boxster S’s on-road prowess. The Porsche’s mid-chassis engine placement means there's less centrifugal actions tugging on your intentions when connecting corners on a backroad.
 
Also sourced from the 911, the Boxster's mechanically variable steering rack's ratio becomes quicker when you turn the wheel beyond 30 degrees. The Porsche’s outstanding grip and progressive understeer can quickly blend to progressive oversteer by simply prodding its sensitive throttle.

Where some roadsters need an open track and white-knuckle antics to test their measure, the Porsche can be equally as satisfying on public roads. The Boxster S's user-friendliness allows the car’s sizeable capabilities to grow on you.



TIN-TOP ALTERNATIVE: 2007 Porsche Cayman 2.7 6M $69,600
 
WHY BUY?:  Power back the cloth top, take advantage of the faithful reactions from the Porsche’s steering wheel and well-controlled chassis. Now indulge in the sumptuous mechanical symphony from the flat-six and see why the Boxster is the best roadster for the road today.

- John LeBlanc, Publisher, www.straight-six.com
 
FIRST PLACE: 2007 Porsche Boxster S 6M
Price: base/as tested $63,600/$80,395
Engine: 3.4-litre six-cylinder gasoline
Power/torque: 295 hp/251 lb.-ft.
Fuel consumption: (L/100 km) city 11.8, hwy 7.7, as tested 9.6
 
SECOND PLACE: 2008 Audi TT Roadster 2.0 TFSI S tronic
Price: base/as tested $53,600/$60,000
Engine: 2.0-litre turbocharged four-cylinder gasoline
Power/torque: 200 hp/207 lb.-ft.
Fuel consumption: (L/100 km) city 7.9, hwy 6.2, as tested 7.0
 
THIRD PLACE: 2007 BMW Z4 3.0si 6M
Price: base/as tested $53,900/$66,600
Engine: 3.0-litre six-cylinder gasoline
Power/torque: 255 hp/220 lb.-ft.
Fuel consumption: (L/100 km) city 11.7, hwy 7.1, as tested 10.6

This article originally appeared in The Toronto Star's Wheels