Chevrolet Cobalt XFE earns fuel economy numbers up to 36 mpg
Bob Plunkett, Tue, 29 Jul 2008 08:00:00 PDT
TUCSON, Ariz. -- Pointing west on Speedway Boulevard in Tucson as a traffic signal switches to green, we slot the shifter stick of a manual five-speed stick by Germany's Getrag into first gear and tap the go-pedal on a new XFE edition of the Cobalt coupe from Chevrolet.
The XFE -- signifying "Xtra Fuel Economy" -- is the latest trim variation for Chevy's compact-class two-door coupe and four-door sedan, and it earns tall fuel economy mileage scores of 25 mpg for city driving and as much as 36 mpg on the highway.
All XFE Cobalts carry GM's Ecotec four-pack engine in a dual-cam design displacing 2.2 liters. But the plant has a new 3.74:1 final drive ratio and revised engine calibrations plus other fine-tune measures designed to achieve high fuel economy mileage figures.The Ecotec engine produces 148 hp at 5600 rpm plus 152 lb-ft of torque at 4200 rpm and it links strictly to the five-speed Getrag F23 manual shifter.
With that green light flashing in the signal on Speedway Boulevard, we launch the XFE and it leaps immediately off the line for a run up the gear ladder until we bump against the posted speed limit.
It's by no means a powerful speed machine, but the XFE certainly feels lively in lower gear ranges, even frisky.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 air conditioning, an audio kit with AM/FM/CD/MP3 and the subscription-based XM satellite radio service.
The XFE Cobalt offers trims of LS and 1LT for coupe or sedan packing the manual transmission exclusively.Pricing is affordably low, beginning at $14,225 for LS trim.
Yet Chevy lists a number of other versions for Cobalt, and two additional powertrains.Cobalt conformed as a four-door sedan shows up in four editions from the price-leading Cobalt plus LS plus Cobalt 1LT to the upgraded 2LT and Cobalt Sport packing a 2.4-liter Ecotech engine.
The twin-cam 2.4-liter in-line-four with variable valve timing (VVT) musters 171 hp at 5800 rpm and the torque climbs to 167 lb-ft at 4500 rpm.Optional in place of the Getrag five-speed manual is a four-speed automatic transaxle with electronic controls, the Hydra-Matic 4T65-E by GM.Cobalt the two-door coupe also brings a price-leading base trim with the LS, along with the 1LT and upgraded 2LT.
However, the coupe Cobalt SS is a different animal -- more like a 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, 18-inch forged aluminum wheels and Y-rated Continental 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 2.0-liter Ecotec DI (direct injection) four-pack fitted with the turbo-charger and air-to-air inter-cooling system.When tied to the "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 -- were revised to complement the SS's turbo-charged muscle.
For instance, the suspension -- consisting of 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 big disc at each wheel with front vented rotors and 38-mm four-piston Brembo calipers plus 11.5-inch discs at the rear with 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 electronic skid controller, StabiliTrak. 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 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 also carries a high-flying wing spoiler on the tail.For Cobalt 2LT the optional Performance Appearance Package attaches a tail spoiler, 16-inch aluminum wheels, foglamps, white-face instruments and leather on the steering wheel.
New gear for every 2008 Cobalt includes a tire pressure monitoring system (TPMS) and the curtain-style air bags.Layout of Cobalt's cabin amounts to a pair of bucket seats in front of a bench for three with split/folding seatback.The MSRP for Cobalt 1LT tallies to $14,935, with Cobalt Sport listing for $19,510 and the coupe Cobalt SS beginning at $22,335.