Vehicular metrics
There are a broad range of metrics that denote the relative capabilities of various vehicles. Most of them apply to all vehicles while others are type-specific.
| Measurement | American unit | Metric unit | Affects | General preference | Notes |
| 0 to 100 km/h | seconds | seconds | acceleration | lower is better | |
| 0 to 100 to 0 mph | seconds | seconds | acceleration & braking | lower is better | formerly common in British publications |
| autonomy | kilometers | comfort | higher is better | ||
| Braking distance | feet | meters | safety | shorter is better | |
| Brake specific fuel consumption | lb/ | g/ | economics, range | lower is better | |
| Drag coefficient | economics, top speed, range | lower is better | |||
| traveled Distance | kilometers | economy | higher is better, lower is better for a second hand acr | ||
| Frontal cross-section area | sq ft | m2 | economics, top speed, range, cargo capacity | lower is better | if area is too small, vehicle becomes difficult to use |
| Fuel economy | mpg | l/100 km and km/L | economics, range | greater is better, lower is better | must be specified on new vehicles for sale in the US & UK |
| Maximum g-force | g or ft/s2 | g or m/s2 | acceleration, braking | higher is usually better | measures cornering, braking or forward acceleration |
| Ground pressure | psi | pascals | traction | lower is better in soft ground, reduces bogging; higher with loose surface | has greater impact on off-road vehicles |
| Lift to drag ratio | - | - | economics, range | higher is better for aircraft | improved by narrow, long wings |
| Noise | dB | dB | comfort | lower is better | |
| Torque | lbf·ft or lb·ft | N·m | acceleration | higher is better | Refers to the overall maximum torque an engine can produce, or the maximum torque an engine can produce at a given RPM. 300 lbf·ft would be like applying 300 pounds of force to the end of 1 foot long wrench, or twisting a 2-inch diameter shaft with 3600 pounds of force! |
| Power | hp | kW | acceleration | higher is better | Refers to maximum power. The rate at which torque is applied. Also the rate at which work is done. Power = Torque × RPM / 5252. Automobile manufacturers publish power measured at the crankshaft. However, it is the power a car can produce at the wheels that matters when it comes to acceleration performance. Wheel horsepower equals brake horsepower minus drivetrain losses, which can be anywhere from about 10% to 25%. |
| Power-to-weight ratio | hp/lb | W/kg | acceleration | higher is better | |
| Second moment | psi | kg·m2 | handling | lower permits quicker turn-in for cars, higher is more stable in straight line. | The moment of inertia about a vertical axis of a vehicle |
| Propulsive efficiency | % | % | economics, range | higher is better | For rockets and aircraft, percent of the energy contained in a vehicle's propellant converted into useful energy |
| Rate of climb | feet/min | meters/min | combat effectiveness, economics | higher is better | Applies to fighter aircraft who need to intercept or evade other fighters. In civilian aircraft this denotes how quickly they can reach optimal cruising altitude. |
| Roll center | inches | mm | handling | Too many variables to state a general preference. | |
| Rolling friction | - | - | economics | lower is better | improved by narrow, high pressure tires |
| Size | - | meters | handling, safety | lower is better for parking on narrow parking slots, higher is better for lateral Traffic collision | |
| Shift time | mSec | ms | acceleration | lower is better | for vehicles equipped with automatic transmissions |
| Specific fuel consumption | lb/ | kg/ or g/ | economics, range | lower is better | in airbreathing jet engines it is improved by using more inert air for propulsion, in rockets, higher exhaust velocity |
| Specific fuel consumption | lb/ | kg/ | economics, range | lower is better | for shaft engines less fuel use for a given output power means higher efficiency |
| specific impulse | seconds | seconds or kN·s/kg | economics, delta-v/range | higher is typically better | in airbreathing jet engines it is improved by using more inert air for propulsion, in rockets, higher exhaust velocity |
| Top speed | mph | km/h | Maximum rate of straight line travel | higher is better | Electronically limited in some cars for safety A speed greater than the legal maximum/recommended speed limit can be considered as useless/unsafe. |
| Turning radius | feet | meters | handling | lower is better | |
| Weight, mass or Dry weight | lb | kg | acceleration, braking distance, traction, fuel consumption, tyre wear | lower is better for vehicle performance and taxation; larger is usually better for vehicles carrying loads | |
| Weight distribution | % | % | handling, acceleration, traction | close to 50:50 is commonly considered better | |
| Gross axle weight rating | lb/axle | kg/axle | :wikt:durability|durability, economics | larger is better for vehicles carrying loads | Ultimately limited by the hardness of the road surface and legal limits intended to limit damage to it |