I'd bet that anyone would tell you that 2 mph at somewhere near 55-65 mph is within +- 1% which is where anyone could/should expect a speedometer to be accurate ...
That would be a way to save themselves from you blaming them for reporting a slower speed which resulted in you getting pulled over and getting a ticket.Yea I think that is still pretty accurate. It could be that the Garmin is wrong and your car is right too.
Sometimes I think the manufacturer may purposely make it say you are going 2 mph faster than you actually are to stop you from speeding or something like that.
I've experimented with that with a few vehicles of mine and rentals and i end up being able to go 5-10 miles more than claimed.They do the same thing with fuel gauges. That is why empty isn't actually empty. You can still drive for a while longer.
I agree. Not good to push it because you could run out of fuel and because its bad for your car. But how many times have you really been pushing to get to the gas station basically on empty. Imagine if empty literally meant empty.I've experimented with that with a few vehicles of mine and rentals and i end up being able to go 5-10 miles more than claimed.
But getting that low in fuel and often isn't good for your fuel pump.
This is good to know. I had never looked up the exact regulations, I just guessed based on what makes sense to me. I wonder if you take it in if they can adjust it or something?The speedometer is not a precise instrument. Precise instruments only work under laboratory conditions (steady temperature, humidity, environmental air pressure etc.).
Therefore the (European Community) car regulations foresee following regulation / allowable deviation for speedometers :
Example : when you drive 100km/h your speedometer CAN indicate a speed in a range from 100 km/h up to 114km/h (100 +10% + 4 km/h).
- The speedometer may NEVER indicate a speed lower than the actual driven speed.
- The speedometer MAY indicate a speed equal to the actual driven speed or a higher speed within this limit : ‘actual speed + 10% + 4 km/h’.
So far the theoretical approach.
Normally seen the car manufacturers order their suppliers to deliver speedometers with the smallest possible deviation, but as I wrote before the speedometer is not a precise instrument !
So if you drive 2 identical cars it is most possible that they indicate a different speed when the actual driven speed is the same…
I hope this explanation helps to clarify this phenomenon.
Best regards from Belgium / Europe