Automobile speedometers are not always accurate. Some are as even as 10% off or bounteous. This has various meaningful implications. Whether your speedometer is reading elevated, you're probably going slower than you want to, and aggravating drivers carry on you. Moreover, your odometer reading is probably advancing very quickly, running you elsewhere of warranty faster. Create down the symbol on the mile marker and the date you passed it at, including seconds.3. Repeat process 2 for the next 5 miles, or even 10 miles if you can. The longer the distance, the more accurate your measurement will be.
1. Own your cohort ride at the quickness string based on your motorcar's speedometer, maintaining fixed rush as even as credible.
2. Trial your Clock as soon as you pass a mile marker. Whether your speedometer is reading low, you may bushy-tailed be man to repeated speeding tickets, costing you bankroll and clock.The consequent Testament appearance you quickly and easily verify whether your speedometer is accurate, and whether not, Until when off it is and in which progression.
Instructions
Verifying the accuracy of your car's speedometer
4. Subtract the number of the first mile marker from that of the last mile marker. If the number is negative, drop the minus sign and make it positive.
5. Subtract the time you passed the first mile marker from the time you passed the last one. Translate the difference into seconds.
6. Divide the number of miles from step 4 by the number of seconds from step 5. This is your measured average speed in miles per second and should be about 0.0153 if you're going at 55 mph.
7. Divide your measured average speed by the speed your speedometer was showing in mph throughout the measurement. Multiply the result by 3600. If the final number is 1.0 congratulations, your speedometer is accurate. If the number is higher than 1.0, your speedometer is reading low and you're going faster than you think. If the number is lower than 1.0, your speedometer is reading high, and you're going slower than you think.
8. Subtract 1.0 from the number you arrived at in step 7, and multiply the result by 100. This is the percentage error of your speedometer. If the number is +9%, you're traveling 9% faster than you think. If it's -5%, you're traveling 5% slower than you think.
