3 ms·

Really doubt you are legally allowed to use GPS based speedometer in place of actual one either.

by varjag 8y ago

cronix 8y ago
Ok, but it's more accurate than the spedometer in my higher end car, which seems to be off by about 4.6mph lol. I was always wondering why those speed radar things on the side of the road that tell how fast you are going (usually in residential neighborhoods) were consistently showing me going about 5mpg slower than my car was indicating until I checked with my phone gps. So, I was consistently going about 5 mph under the posted speed limit because apparently BMW can't make a decent speedometer gauge! The fuel gauge in my dads pickup is also really whacked. Once it hits about 50% fuel left, it rapidly goes down to 0. Cars don't burn though higher rates of fuel just because of how much is in the tank.
- detaro 8y ago
  At least in some places, e.g. here in Germany, the speedometer is never allowed to show a slower speed than the car is actually going, so they err on showing too fast (up to 10% allowed I think) so that never happens, even if you put the fattest tires allowed for the model on etc.
- dep_b 8y ago
  I never had a car that actually had the same speed as I was driving. Always 5Km/H below it. You’re expected to drive 120Km/H where the limit says 120. If driving 121 would give you a fine that would be problematic.
- varjag 8y ago
  All speedometers are regulated into slight plus from the wheel speed. This ensures you are not speeding unaware of it. Aside from the calibration issue, GPS has poor or no coverage in tunnels, underpasses, mountainous areas and between dense urban high rises. Prone to EM interference too. Not a good thing for safety critical device.
maxerickson 8y ago
Are there jurisdictions that require a speedometer, vs requiring people to obey speed limits?
- varjag 8y ago
  Most places I know about require that all driving-related equipment your car is fitted with should work. E.g. it's fine if your car has no ESP or ABS, but if it does it has to work. If your car had no turn lights or seatbelts originally it passes the inspection, but of course not if they simply don't work. So perhaps if you drive early model Ford T no speedometer is fine, but otherwise seriously doubt it.

Really doubt you are legally allowed to use GPS based speedometer in place of actual one either.

by varjag 8y ago

Really doubt you are legally allowed to use GPS based speedometer in place of actual one either.

Ok, but it's more accurate than the spedometer in my higher end car, which seems to be off by about 4.6mph lol. I was always wondering why those speed radar things on the side of the road that tell how fast you are going (usually in residential neighborhoods) were consistently showing me going about 5mpg slower than my car was indicating until I checked with my phone gps. So, I was consistently going about 5 mph under the posted speed limit because apparently BMW can't make a decent speedometer gauge! The fuel gauge in my dads pickup is also really whacked. Once it hits about 50% fuel left, it rapidly goes down to 0. Cars don't burn though higher rates of fuel just because of how much is in the tank.

detaro 8y ago
At least in some places, e.g. here in Germany, the speedometer is never allowed to show a slower speed than the car is actually going, so they err on showing too fast (up to 10% allowed I think) so that never happens, even if you put the fattest tires allowed for the model on etc.
dep_b 8y ago
I never had a car that actually had the same speed as I was driving. Always 5Km/H below it. You’re expected to drive 120Km/H where the limit says 120. If driving 121 would give you a fine that would be problematic.
varjag 8y ago
All speedometers are regulated into slight plus from the wheel speed. This ensures you are not speeding unaware of it. Aside from the calibration issue, GPS has poor or no coverage in tunnels, underpasses, mountainous areas and between dense urban high rises. Prone to EM interference too. Not a good thing for safety critical device.

maxerickson 8y ago

Are there jurisdictions that require a speedometer, vs requiring people to obey speed limits?

varjag 8y ago
Most places I know about require that all driving-related equipment your car is fitted with should work. E.g. it's fine if your car has no ESP or ABS, but if it does it has to work. If your car had no turn lights or seatbelts originally it passes the inspection, but of course not if they simply don't work. So perhaps if you drive early model Ford T no speedometer is fine, but otherwise seriously doubt it.