Chevrolet's Cobalt replacement is big on fuel economy
Nina Russin, Mon, 09 Jul 2012 04:57:05 PDT
It's easy to attach an "eco" badge to a car's rear fender. Backing the claim up is a whole different matter. Over the past week, I decided to see for myself whether Chevrolet's new Cruze Eco compact sedan lives up to its moniker.
I drove like a gorilla fleeing the zookeeper. Jackrabbit starts became my stock and trade. I barreled through rush hour traffic, and bolted up the Beeline Highway between Phoenix and Payson. I never put the car in sixth gear and never used the cruise control.
At the end of a week and about 120 miles, I checked average fuel economy on a digital display in the Cruze's gauge cluster. I had averaged 44.8 miles-per-gallon. While the cynic in me might doubt the display's accuracy, I had to admit that there was still a lot of gas left in the tank.
The Cruze had equaled, or outperformed several popular clean diesel and gasoline/electric hybrids with a simple internal combustion engine. How, readers might wonder, is that possible?
The answer is this: internal combustion engines are inherently inefficient. There's a lot of room for improvement.
In the days before computer controls, most car engines were about forty percent efficient. Sixty percent of the gasoline going into the fuel system was either lost to internal friction or went out the tailpipe as toxic emissions.
More recently, engineers raised engine efficiency to about sixty percent, thanks to computer controls.
What the engineers at Chevrolet did was raise the bar further, developing an engine which combusts gasoline more completely.
Variable valve timing enhances fuel economy by changing the time at which the intake and exhaust valves open and close according to the engine's needs. An exhaust-driven turbocharger boosts airflow through the engine to burn more of the fuel in the combustion chambers.
A returnless fuel line warms up faster, so that the car's computer controls can take over more quickly after start-up. The fast light-off oxygen sensor tells the on-board computer how much gasoline and air to deliver to the engine. This version reacts more quickly to exhaust gas readings than older O2 sensors, so the air/fuel mixture going into the engine is more accurate.
A six speed manual transmission with large overdrive gears extends gas mileage even further.
The engine's small dimensions minimize weight under the hood, while the use of high strength steel and composites throughout the body keeps the rest of the chassis light. Curb weight for the Cruze Eco is just over 3100 pounds, which is on the light side, even for a small sedan. The less mass, the less energy it takes to move the vehicle forward.
Finally, work in the wind tunnel kept the Cruze's coefficient of drag to a minimum. Unlike other Cruze models, the Eco grade comes with an aero performance package which includes a lower front grille air shutter, front fascia air dam and mid-body aero panels.
Priced below $20,000
MSRP for the 2012 Chevrolet Cruze Eco is $19,245, not including the $750 delivery charge. Standard comfort and convenience features include keyless entry, a six-speaker audio system with XM radio (including a three month subscription) and a USB port, Bluetooth interface, a tilt-and-telescoping steering column with redundant steering wheel controls.
A convenience package adds six-way power driver's seat controls and rear parking assist ($495), bringing the price as tested to $20,490.
Enhanced handling and performance
The Cruze is Chevrolet's replacement for the compact Cobalt. While designers could have simply put a new name badge on a slightly revamped platform, they didn't take that shortcut. The Cruze is a clean sheet of paper car, which is evident not only in its contemporary styling, but its superior ride and handling.
One of the biggest differences between the outgoing Cobalt and the new Cruze is much improved torsional rigidity. By enhancing stiffness throughout the body, engineers were able to give the Cruze better steering response. This is especially evident in its on-center response on the highway.
Both the naturally-aspirated engine in the base Cruze and the turbocharged block in the Eco version are smooth performers. A few years back, it was unheard of to use such small blocks, simply because they couldn't deliver the throttle response or power drivers needed.
However, advances in fuel injection technology and new, smarter transmissions have made it possible for small engines to deliver a solid band of power which works in stop-and-go-traffic and on the highway.
An electric power steering system is lighter than the equivalent hydraulic unit, and easier to package under the hood. This one is well tuned to the chassis, delivering appropriate response at all speeds.
The independent front and torsion beam rear suspension isn't state of the art, but it delivers a nicely compliant ride for the front-wheel drive platform. All Cruze models come with disc brakes up front and drums in the rear. Although most of the braking occurs up front, I have concerns about drum brake performance in wet weather.
Visibility around the car's perimeter is good. The side mirrors do a good job of compensating for blind spots in the rear corners. Over-the-shoulder visibility is pretty good, despite rather thick B pillars. The optional rear park assist sounds an audible alarm if the back of the vehicle comes too close to an obstacle.
The Cruze Eco interior is stylish and functional. I found the driver's seat comfortable on drives lasting up to two hours. Controls on the steering wheel and center stack function intuitively. There is an abundance of cup and bottle holders throughout the car, including all four doors.
The shift lever for the manual transmission is easy to use. A standard reverse lockout ring prevents the driver from mistakenly shifting into reverse.
Although three small adults can fit in back, two will be more comfortable. The location of the center console takes up most of the legroom in the center position.
The standard six-speaker audio system produces good sound quality. Engineers minimized road, engine and wind noise intrusion into the passenger compartment, so it's easy for both rows to converse or enjoy the audio.
Second-row seats fold flat to extend the cargo floor. Although the Cruze isn't a practical car for cyclists who need to load bikes into the back, there's plenty of room in the trunk for luggage, groceries and small camping equipment.
The Chevrolet Cruze comes with front, side and side curtain airbags, antilock brakes, traction and stability control. Standard OnStar automatically notifies police and emergency medical personnel if the airbags deploy. The service can also download turn-by-turn directions into the vehicle.
The sedan received five-star federal crash test safety ratings for frontal and side impacts.
Chevrolet builds the Cruze at its Lordstown, Ohio assembly plant.
Likes: An extremely fuel-efficient compact sedan with a high level of standard safety, comfort and convenience features.
Dislike: Rear drum brakes do not perform as well as discs in wet weather.
Model: Cruze Eco
Base price: $ 19245
As tested: $20,490
Horsepower: 138 Hp @ 4900 rpm
Torque: 148 lbs.-ft. @ 2500 rpm
Antilock brakes: Standard
Side curtain airbags: Standard
First aid kit: N/A
Bicycle friendly: No