The already notorious Pontiac Solstice is about to be cloned with a more elegant skin as the Saturn Sky for the US and Opel GT for the European market. The new comers will use the same “Kappa” production platform as the Pontiac, but will be distinctive in terms of design.

  • 2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
  • Year:
  • Make:
  • Make:
  • Make:
  • Model:
  • Model:
  • Model:
  • Engine:
    SIDI Turbo Ecotec Aluminum Inline-4
  • Transmission:
    5-Speed Manual
  • Horsepower @ RPM:
    260 @ 5300
  • MPG(Cty):
  • Torque @ RPM:
    260 @ 2000
  • Displacement:
    121.9 L
  • 0-60 time:
    5.4 sec.
  • Quarter Mile time:
    12.5 sec.
  • Top Speed:
    145 mph
  • 0-100 time:
    16.3 sec.
  • Layout:
    Front Longitudinal
  • car segment:

The Pontiac Solstice was first presented to the public as a concept roadster at the 2002 Detroit NAIAS (North American International Auto Show). Designed in not more than four month, the prototype promised to offer open-air freedom-enhanced sportiveness in the manner roadster from the past used to.


The great success of the Solstice concept encouraged GM to prepare it for production. At the moment the prototype was developed General Motors didn’t had any small rear-wheel-drive platform that could be used for such car. Therefore, a brand-new platform had to be developed for the Solstice.


The complete new “Kappa” architecture allowed the production vehicle to remain true to the original Solstice prototype with RWD and the original reverse hinged clamshell hood. As Bob Lutz, Bob Lutz, chairman of GM North America said, “the production Solstice is all about being a ‘back-to-basics’ roadster with gorgeous lines and fun-to-drive characteristics”.


In order to make the “Kappa” platform profitable GM made use of several already proven components. Such component is the Opel borrowed ECOTEC DOHC R4 naturally aspirated engine used for the base model. Displacing 145 cui and making use of aluminum for the lightweight construction this power-plant boasts 170 bhp, enough to propel the car up to 123 mph. For production start, Solstice was offered with a close-ratio Aisin five-speed manual transmission.


Not only technical components come from other GM architectures. Body parts like the rear corner lamps, door handles, fog lamps and the seats are shared with other GM vehicles in order to make the roadster more affordable.


Further cost reductions could be achieved by building several vehicles on the “Kappa” platform. Therefore, GM decided to bring to production another roadster concept, the Vauxhall VX Lightning. This car was designed for Vauxhall’s 100th anniversary by GM’s Advanced Design Studio in Birmingham, England. It will be produced as the Saturn Sky for the US Market and as Opel/Vauxhall GT for the European market.


It is not hard to recognize the new Sky/GT as Solstice clones despite the redesigned body.

The general look of the car is more subtle and elegant where Solstice was aggressive. In addition, the interior is more upscale with a horizontal dash that replaces Solstice’s cockpit, designed to surround the driver.

2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 85987

Another mission for the Sky, besides that of getting “Kappa” profitable, is to reposition Saturn up market, past Pontiac. As declared by GM representatives the Sky displays the new design lines that will be common to all new Saturns. This is quite interesting if we remember that this design was taken from a Vauxhall prototype. Maybe it was intended to be so, as Saturn will be now repositioned on the import-fighting market area that used to be Oldsmobile’s charge. As we know Oldsmobile wasn’t very successful at that; maybe European styled Saturns will get to counter German import vehicles.


Another interesting marketing trick GM is pulling is that the same design (having literally only the badge replaced) will be sold to Europe as the Opel GT, the presumptive reincarnation of the famous coupe of the 70s. So, let’s summarize: the new design of the Pontiac Solstice roadster with minor adjustments can bring a new fresh spirit to the Saturn brand and, in the same time, can become the reincarnation of a famous European coupe of the 1970s. All of that at a minimum cost. If it will manage to pull all of that up, only the market will decide. 


As the Saturn Sky is intended to be more luxurious, it will have standard features that’ll be only optional on the Pontiac Solstice, like power windows, remote locking, and air-conditioning, which will not be standard on the Pontiac in order to keep the price under $20,000. However, all the equipment featured on the Sky will also be available on the Solstice as an option, making these two cars actually different only in detailed styling.


Both cars got a recent high-performance version equipped with a supercharger that delivers 260 bhp and reduces the 0-60 mph sprint to less than 5.5 seconds. These improved models will be called GXP for Pontiac and Red Line for Saturn.


The new Saturn Sky along the European brother Opel GT will be built in Wilmington/Delaware, in the USA, where the sister model, the Pontiac Solstice is also produced.


The original Opel GT owed much to the USA - in several respects. Its breathtaking lines were inspired by a new American design style, the so-called “coke bottle shape”, which also defined the Corvette Stingray. Furthermore, two thirds of all Opel GT cars built have been exported to the United States.

2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 85988

Technical overview


The strong positive response to the 2002 Pontiac Solstice concept vehicle put the roadster on the fast track to production. Although the concept was designed with production-ready elements, there was no compact RWD platform at GM at the time for building it. Creating a production version of the prototype required an entirely new performance body-chassis architecture.


This new platform specially developed for the Solstice was called the “Kappa”. It is built around full-length hydro-formed frame rails and a stamped steel structural tunnel that provide a solid structure to enhance vehicle handling.


The proportions of the new car are faithful to the concept in terms of overhangs, wheelbase and track width. The sporty character suggested by the body design is being technically supported through independent front and rear suspensions that feature SLA designs with forged aluminum upper and lower control arms that contribute to responsive handling. Uncompromised handling response and sporty driving characteristics are further attained by the use of monotube shock absorbers and coil springs. The extreme positioning of the wheels, towards the corners of the car produces an aggressive stance and enhances handling. 18” wheels and tires are standard, as are four-wheel disc brakes.

2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 85989

The Pontiac Solstice’s proportions are further accented by the five-spoke ultra-light alloy wheels. The dual-port grille and the expressive lights placed at the car’s corners clearly state that the Solstice is a member of the Pontiac family. Original and eye-catching details include the body-color extension into the passenger compartment that gives an integrated appearance when the top is down. The top of the cat folds flat into the rear clamshell opening, providing a smooth seamless appearance, but, unfortunately, when doing that it occupies almost all the boot room.


The Saturn Sky / Opel GT identical twins GM happily have the genes of their elder Pontiac brother and seem to have had as a parent the Vauxhall Lightning styling. Solstice’s Rubenesque curves have been replaces with sharp edge-design creases that remind of the Opel / Vauxhall styling.

2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 85990

Vehicle Dimensions


weight 2860 lbs (2948 lbs for supercharged version)

wheelbase 95.1 in
front track 60.5 in
rear track 61.2 in
length 157.2 in
width 71.6 in
height 50.2 in

Engine & transmission


The element of novelty for the 2006 Solstice GXP as well for the Saturn Sky Red Line is the Ecotec 122 cui turbo engine, GM’s first direct injection offering in the US. This Opel developed unit produces 260 horsepower and 260 lb.-ft. of torque making it GM’s highest specific output engine ever, at 2.1 horsepower per cubic inch of displacement and the most powerful production engine in the Ecotec family.


Responsible for most of that performance is the dual-scroll turbocharger with a lightweight turbine and an air-to-air intercooling system that boosts the turbo’s performance by reducing inlet temperatures. The turbo charging system is complemented by dual cam phasing that optimizes valve timing at lower rpm for best turbo response and quick access to engine torque.


A new addition to this type of an engine is the direct injection technology that helps the engine produce more power while maintaining low fuel consumption in comparison with a port-injected engine. With the direct injection system, the fuel is delivered directly to the combustion chamber to create a more complete burn of the air/fuel mixture. Less fuel is required to produce the equivalent horsepower, especially at normal cruising speeds, of a conventional port-injection combustion system.


The Solstice GXP and the Sky Red Line get their turbo engines connected to a standard five-speed manual gearbox, or an optional five-speed automotive transmission. Either transmission can propel the cars from zero-to 60 mph in under 5.5 seconds.

2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 85991

Specs for 145 cui NA engine


engine  Ecotec Inline-4

valvetrain DOHC Variable Valve Timing & Intake Manifold

displacement 145.5 cu in
power 177 bhp @ 6600 rpm
hp per liter 70.83 bhp per liter
bhp/weight 131.07 bhp per weight
torque 166 ft lbs @ 4800 rpm
redline 6900
drive wheels RWD
body / frame Steel Body over Aluminum & Steel Chassis
front brakes Vented Discs w/ABS
rear brakes Discs, ABS
front wheels 18 x 8.5 in
rear wheels 18 x 8.5 in
front tire size P245/45R18 Goodyear
rear tire size P245/45R18 Goodyear
f suspension Wishbones, Coil-Over Shocks
r suspension Wishbones, Coil-Over Shocks
transmission MW5 Aisin 5-Speed manual
gear ratios 3.75:1, 2.26:1, 1.37:1, 1.00:1, 0.73:1
final drive 3.91:1
top speed 123 mph
0 - 60 mph 6.8 seconds
0 - 100 mph 21.3 seconds
0 - 1/4 mile 15.5 seconds
epa city/hwy 24 mpg
2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 85992

Specs for 122 cui supercharged engine


engine  SIDI Turbo Ecotec Aluminum Inline-4

valvetrain  DOHC, 4 Valves per Cyl, Variable Valve Timing & Intake Manifold

fuel feed Direct Injection
displacement 121.9 cu in
bore  3.39 in
stroke 3.39 in
compression 9.2:1
power 260 bhp @ 5300 rpm
hp per liter 130.13 bhp per liter
bhp/weight 200.46 bhp per tone
torque 260 ft lbs @ 2000-5300 rpm
redline  6300
drive wheels RWD
body / frame Steel Body over Aluminum & Steel Chassis
front brakes Vented Discs, ABS
f brake size 11.7 in
rear brakes Solid Discs, ABS
r brake size 10.9 in
front wheels x 8 in
rear wheels 18 x 8 in
front tire size P245/45R18- Goodyear Eagle F1 GS2 96W
rear tire size P245/45R18- Goodyear Eagle F1 GS2 96W
steering Rack & Pinion
f suspension Wishbones, Coil-Over Shocks
r suspension Wishbones, Coil-Over Shocks
transmission  MW5 Aisin 5-Speed Manual or Auto
gear ratios 3.75:1, 2.26:1, 1.37:1, 1.00:1, 0.73:1
final drive 3.73:1
top speed 145 mph
0 - 60 mph 5.4 seconds
0 - 100 mph 16.3 seconds
0 - 1/4 mile 12.5 seconds
epa city/hwy 21 mpg
2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 85993



All of the “Kappa” architecture roadsters get a sporty cockpit oriented around the driver, with clean design and intuitive controls. The interior is surprisingly spacious, especially for cars of this size. As Lori Queen, vehicle line executive for GM’s small cars said the interior design was done by trying to ”create a comfortable environment suitable for longer drives without sacrificing the ‘personal’ feeling of a driver’s car.”


The overall impression of the interior design is that of a dynamic and young environment, equally purposeful and clever. Some details like the pedals placed as for easy heel-and-toe driving invite to a sporty driving manner. A special attention was placed on the positioning of the gear shifter. Interior designers teamed up with chassis engineers to optimize the placement of the gear-shift lever. As interior designer Vicki Vlachakis says

2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 86018

“when you sit down in the car, your hand naturally falls onto the shifter”. “It’s a very intuitive, comfortable environment, and the feel of the shifter between gears is very short and precise. Designers and chassis engineers worked together to tune the best placement.”

Closing comments

Up until now, only three vehicles got use of the “Kappa” platform. The Sky and the Solstice seem to be different enough in design not to “cannibalize” each other. The Sky and the Opel GT are practically identical, but due to the fact that they will be sold on different markets that doesn’t seem redundant. If the “Kappa” architecture doesn’t get passed on to other GM brands, such as Chevrolet, Buick, Saab, Cadillac (or maybe even Hummer!!!) its purposefulness seems fulfilled. For the US buyer, choosing between a Pontiac Solstice and a Saturn Sky is only a matter of taste, since the difference between the two is reduced to design. An advantage of the Pontiac is that it comes in a cheaper version that is available for under $20,000.

2006 GM just had roadster triplets: Pontiac Solstice, Saturn Sky, Opel GT
- image 86019
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