On the Road Cover Story
cars.com On the Road Weekly Publication
9:59 AM EDT, March 14, 2012
By Jim Gorzelany
Most new-car brochures and web pages feature a list of various numbers and measurements, usually called “specifications,” which can be cryptic at best for all but the most knowledgeable auto enthusiasts. Still, they relate important information for car shoppers who are looking to compare the intricacies of various makes and models before heading for a dealer’s showroom.
Here’s how to decipher many of the numbers listed in a typical new-vehicle specs chart.
• Engine Displacement/Cylinders. Expressed in liters, displacement is a rough indication of how “large” an engine is, specifically indentifying the volume within its cylinders. More cylinders mean a larger displacement and usually more power.
• Horsepower. Strictly defined as the amount of energy required to lift 550 pounds a distance of one foot in one second, horsepower is used to quantify an automobile engine’s maximum power output.
• Torque. This is the measurement of how forceful an engine gets up to speed. All else being equal, a car with a higher torque rating (expressed in terms of pounds/feet) will feel quicker from a standing start or when passing on the highway.
• Fuel Economy. All vehicles are rated by the Environmental Protection Agency for their fuel consumption in city, highway and combined city/highway driving, albeit based on rigidly controlled tests conducted in a laboratory. While the EPA ratings are a valuable source of comparison, factors like trip length, traffic, terrain, temperature and a motorist’s driving style all will affect a car’s real-world mileage.
• Drag Coefficient. Expressed as a number followed by the abbreviation Cd, this measures a car’s aerodynamics. Lower numbers indicate less resistance to drag, particularly at higher speeds; a car with better aerodynamics is often quicker and more fuel-efficient.
• Curb Weight. This indicates a vehicle’s weight measured without options, passengers or cargo. All else being equal, a lighter car will usually be quicker and get better fuel economy since the engine doesn’t have to work as hard. On the down side, the laws of physics dictate that a smaller and lighter model will fare worse in a collision than will a larger and heavier one.
• Towing Capacity. This indicates the maximum weight a given model can tow when properly equipped. Experts usually caution motorists to leave some leeway when choosing a boat or trailer based on a vehicle’s towing capacity so as not to overtax key components.
• Wheelbase. This measures the distance between the centers of a car’s front and rear axles. A vehicle having a longer wheelbase tends to ride smoother and afford more interior room than one having a shorter wheelbase.
• Overall Length/Width/Height. These are a car’s basic dimensions and are invaluable for determining how well a given model will fit in a garage. Note that a vehicle will wind up being incrementally taller if fitted with an optional roof rack and/or larger wheels and tires
• Turning Radius. Expressed in feet, this indicates the smallest circular turn a vehicle can make. A car with a “tighter” turning radius usually steers quicker through turns and is easier to parallel park.
• Passenger Volume. This measures a car’s total interior space, expressed in cubic feet, though it’s not always a good indication of how accommodating it will be to passengers. To that end, it’s a better idea to compare figures for front and rear head, leg, shoulder and hip room, all of which are given in inches.
• Cargo Volume. Expressed in cubic feet, this measures either trunk space or the size of a cargo hold behind the seats, depending on the vehicle type. A separate figure may be included for maximum cargo volume, which indicates what the vehicle could hold with the rear seatbacks folded flat.