Introduced in the fall of 2004 as a 2005 model, the midsize G6 was GM's replacement for the outdated, unloved Pontiac Grand Am. It was built on the company's front-wheel-drive Epsilon platform, which also underpinned the Chevy Malibu, Saturn Aura and Saab 9-3.
Though it was an improvement over its predecessor in nearly every way, the G6 failed to connect with consumers, many of whom were loyal to segment leaders like the Honda Accord and Toyota Camry. The G6's disappointing interior and polarizing styling turned off some potential buyers. A limited, poorly conceived advertising campaign also contributed to lackluster sales. Making matters worse, many in the automotive press argued that the similarly priced Chevrolet Malibu was a more impressive, better-executed take on the Epsilon platform.
The 2007 model year saw the G6's only substantial update. The range-topping GTP model got a new, more-powerful engine and a six-speed automatic transmission, while the mid-range GT model's base engine received a boost in power. In addition, side curtain airbags and hydraulic power steering were added, along with several new options packages.
The G6 came in coupe, sedan and unusual hard-top convertible body styles. Four trim levels were offered: Value Leader, base, GT and GTP. The sedan was available in all four trims, while the coupe could be had as a GT or GTP. In 2006, the convertible also came in GT or GTP trim, while in 2007 it was available as a GT only.
Though the somewhat oddly named Value Leader was the most stripped-down trim level, it came with an impressive selection of standard equipment. This included 16-inch wheels, power windows, locks and mirrors, air conditioning, a 60-40 split folding rear seat, a CD stereo, a tilt-telescoping steering wheel and a four-way power driver's seat.
The confusingly named base trim level added 17-inch alloy wheels, keyless entry and cruise control. The next level up, the GT, included chrome wheels, a premium, eight-speaker sound system, fog lamps, a stiffer, performance-tuned suspension and a rear spoiler.
Finally, the top-of-the-line GTP model added 18-inch alloy wheels, automatic climate control, an auto-dimming rear-view mirror, XM satellite radio and a six-way power driver's seat.
The 2007 model debuted three new options packages: Sun & Sound, Sport and Premium. The Sun & Sound package comprised a sunroof and an in-dash CD changer. The Sport package varied, depending on which trim level it was applied to. When applied to the base G6, it included the 3.5-liter V-6, antilock disc brakes and hydraulic power steering. The GT with the sport package included an upgrade to the 3.9-liter V-6, stability control, 18-inch wheels and a six-speed manual transmission. Finally, the Premium Package, which was only available on GT and GTP models, featured leather seating surfaces, heated front seats and a remote start function.
Engine selection was the biggest difference between the 2006 and 2007 models. The 2006 G6 was available with a 2.4-liter inline-four, a 3.5-liter V-6 and a 3.9-liter V-6.
The entry-level four-banger produced 167 horsepower at 6,300 rpm and 162 foot-pounds of torque at 4,500 rpm. The mid-range 3.5-liter V-6 put out 201 horsepower at 5,600 rpm and 222 foot-pounds of torque at 3,200 rpm. Finally, the big 3.9-liter six-cylinder engine generated 227 horsepower at 6,000 rpm and 235 foot-pounds of torque at 2,800 rpm. All three engines came standard with a four-speed automatic transmission. For those looking for a sportier, more involved driving experience, G6 models equipped with the 3.9-liter V-6 could be optioned with a six-speed manual.
The 2007 G6 featured the same base inline-four as the previous model year, though peak horsepower increased slightly to 169. The mid-level 3.5-liter V-6 enjoyed a more substantial power boost. For 2007, it produced 224 horsepower at 5,800 rpm and 220 foot-pounds of torque at 4,000 rpm. The 2006 model's 3.9-liter V-6 was replaced by a smaller but more muscular 3.6-liter unit. The G6's new V-6 generated 252 horsepower at 6,300 rpm and 251 foot-pounds of torque at 3,200 rpm. Top-of-the-line GTPs with the 3.6-liter V-6 came with a new six-speed automatic transmission with manual-shift mode. For all other models, the same transmission choices as 2006 carried over unchanged.
The car's dimensions were identical in 2006 and 2007. The G6 sedan measured 189 inches in length, 70.6 inches in width and 57.1 inches in height, with a 112.3-inch wheelbase. The coupe varied only slightly in size. It was 189.1 inches long, 70.4 inches wide and 56.4 inches tall. Like, the sedan, its wheelbase was 112.3 inches. Finally, the convertible measured 189.1 inches in length, 70.6 inches in width and 56.7 inches in height, with the same 112.3-inch wheelbase.
Both the sedan and coupe provided 14 cubic feet of trunk space, while convertible owners had to make due with a meager 5.8.
The G6 was average for its class in term of fuel economy. With the base inline-four, the 2006 model was EPA-rated at 21 mpg in the city and 31 mpg on the highway. With the mid-range 3.5-liter V-6, it received a 20-29 rating. The 3.9-liter V-6-equipped model was rated at 16-24 with the automatic and 16-26 when equipped with the six-speed manual. Finally, the 2006 G6 convertible received a 17-25 rating with the 3.5-liter engine and a 16-24 rating with the 3.9-liter V-6.
The 2007 G6 received similar, though not identical, fuel economy numbers. The inline-four-equipped car was EPA-rated at 20 mpg in the city and 30 mpg on the highway. With the mid-level, 3.5-liter it was rated at 18-28. The top-of-the-line 3.6-liter model received a 17-26 mpg rating. Lastly, the 2007 G6 convertible was rated at 15-22.
When new, the 2006 G6 started from $16,365 for the value leader sedan up to $29,365 for the GTP convertible. In 2007, starting prices ranged from $17,245 to $28,750.The reduction in top-end price was a due to the fact that the pricey GTP convertible was no longer offered in 2007. According to Kelley Blue Book, as of 2014, a used 2006 is worth between $5,225 and $13,775, depending on configuration. A slightly-newer 2007 model should go for $5,825 to $12,335.