Chevrolet Cobalt coupe/sedan earns high miles for fuel burn
Bob Plunkett, Mon, 14 Jun 2010 04:30:10 PDT
TEMPE, Ariz. -- Pointing east on University Drive in the Phoenix suburb of Tempe as a traffic signal switches to green, we pull the stick of a five-speed manual Getrag shifter into the bottom gear slot and tap the throttle on a Cobalt XFE sedan from Chevrolet.
The XFE -- signifying "Xtra Fuel Economy" -- is the low-price trim variation for Chevy's compact-class two-door coupe and four-door sedan and it garners fuel economy mileage scores of 25 mpg for stop-and-go city driving and up to 37 mpg when running faster on a highway.
All XFE Cobalts for 2010 carry GM's Ecotec four-pack engine in a dual-cam design displacing 2.2 liters and outfitted with VVT (variable valve timing) controls. The plant has a 3.63:1 final drive ratio on manual transmission models to enhance fuel economy scores.
The Ecotec engine produces 155 hp at 6100 rpm plus 150 lb-ft of torque at 4900 rpm and for XFE issues the plant links strictly to a Getrag F23 manual transmission.
With that green light flashing in the signal on University Drive, we release the clutch on the XFE and it scoots off the line for a run up the gear ladder.
To be sure, the Cobalt XFE is no speed machine, although it feels lively in lower gear ranges.
And, despite the slant toward economizing on fuel, this Cobalt looks slick and sporty yet still stocks a lot of standard equipment -- from curtain-style air bags to an audio kit with AM/FM/CD/MP3 and the subscription-based XM satellite radio service.
Pricing is affordably low, with the MSRP dipping just below $15,000.
Chevrolet offers other versions of Cobalt for model-year 2010 in coupe and sedan formats, plus a sporty coupe packing a turbo-charged powertrain.
Cobalt conformed as a four-door sedan shows up the price-leading Cobalt LS plus upgraded Cobalt LT.
The 2.2-liter four-cylinder Ecotech engine applies with the Getrag five-speed manual transmission or a four-speed automatic transaxle with electronic controls, the Hydra-Matic 4T65-E by GM.
Cobalt as two-door coupe also brings a price-leading trim with LS as well as the LT upgrade.
However, the coupe Cobalt SS is a different animal -- more like a sleek and swift cheetah.
Engineers at GM's Performance Division developed the Cobalt SS by adding aero-curvy body add-ons, then installing a performance-tuned sport suspension system, split-spoke 18x7.5-inch forged aluminum wheels and Z-rated summer performance tires, plus a turbo-charged four-cylinder engine tied to a quick five-speed manual gearbox produced by GM Powertrain Sweden.
Engine for Cobalt SS is a dual-cam 2.0-liter Ecotec DI (direct injection) four-pack fitted with the turbo-charger and air-to-air inter-cooling system.
When tied to a "no-lift shift" five-speed manual transmission, the turbo plant delivers 260 hp at 5300 rpm with torque of 260 lb-ft at 2000 rpm.
All of the dynamic mechanical systems -- suspension, steering, brakes -- are designed to complement the SS's turbo-charged muscle.
For instance, the suspension -- independent front elements via MacPherson struts and a semi-independent torsion beam in back -- employs SS-specific stabilizer bars, spring rates and damper tuning to deliver a tight, road-hugging ride quality with minimal body pitch when cornering.
In front, there are gas-charged twin-tube struts, coil springs with damper tuning, stiffer bushings and a direct-acting 24-mm solid stabilizer bar.
In back, the change list includes monotube gas-charged shocks, multi-rate coil springs, taut axle bushings and a 24-mm solid stabilizer bar.
An electric power steering (EPS) system for the rack and pinion mechanism scores special tight tuning with a faster (14.8:1 ratio) rack and pinion gear.
Cobalt SS upgrades brakes to a disc at each wheel with 12.4-inch front vented rotors and 38-mm four-piston Brembo fixed calipers plus 11.5-inch rotors at the rear linked to 40-mm single-piston Brembo calipers.
Brakes tie via electronic links to an anti-lock brake system (ABS) with a standard traction control system (TCS) and GM's StabiliTrak electronic skid controller.
Styling for Cobalt's exterior shell appears smooth and tailored on the sedan but it's more sharply drawn with edgy lines on the coupe.
Both sedan and coupe versions feature a distinctive prow with the body-color single-bar grille supporting Chevy's bow-tie badge.
Oversize composite headlamp clusters sparkle on front corners of the face, while a thick plastic fascia underscores the grille.
Flanks are relatively flat but interrupted by subtle flares on wheelwell arches, with counterbalance above coming from smooth roof rails which stretch over an arched cab.
The blunt tail treatment consists of a brief notchback deck on the sedan but a tapered and rolled back window on the coupe.
And pairs of articulated round lamps in red on the flat back panel evoke a signature design for Chevrolet.
Cobalt SS coupe carries a high-flying wing spoiler on the tail. The fascia in front adds an integrated air dam plus projector-beam foglamps, and every 2010 Cobalt SS stocks a power-operated sunroof.
Layout of Cobalt's cabin amounts to a pair of bucket seats in front of a bench for three with the seatback split and folding to add room for cargo.