Elapsed time on a car, often abbreviated as E.T., is a measurement of how long it takes for a vehicle to cover a specific distance from a standing start. It's a crucial performance metric, most famously used in drag racing to time a car's run over a quarter-mile distance. However, it's also the same principle behind common acceleration figures like the 0-60 mph time.
When you see a car's 0-60 mph time listed as 4.5 seconds, that 4.5 seconds is the elapsed time. It's the total duration from the moment the car begins moving until it reaches the 60 mph mark. This measurement is key for understanding a vehicle's acceleration capabilities, which is influenced by factors like engine power, weight, traction, and transmission tuning.
Beyond 0-60 mph, elapsed time is used in various scenarios:
- Drag Racing: The primary timing method for a quarter-mile (1,320 feet) race. A lower E.T. indicates a faster, more powerful car.
- Automotive Journalism: Professionals use precise equipment to measure E.T. for standardized performance reviews.
- Onboard Timers: Some performance cars have built-in timers that allow drivers to measure their own E.T. on a track or closed course.
Here’s a comparison of elapsed times for different vehicle types over the quarter-mile, illustrating performance tiers:
| Vehicle Type / Example | Typical Quarter-Mile Elapsed Time (E.T.) |
|---|
| Top Fuel Dragster | 3.6 - 3.8 seconds |
| Supercar (e.g., Porsche 911 Turbo) | 10.0 - 10.8 seconds |
| Performance Sedan (e.g., BMW M5) | 11.2 - 11.8 seconds |
| Standard Midsize SUV | 14.5 - 16.0 seconds |
| Economy Compact Car | 16.5 - 18.0 seconds |
It's important to distinguish elapsed time from reaction time. Reaction time measures how quickly a driver leaves the starting line after the green light. In competitive drag racing, both times are critical, but E.T. is a pure measure of the car's performance.
