SOLD! Your sister will never forgive you! (The chains won't allow her access...)
I jest ... of course.
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View my fuel log 2020 Mirage ES 1.2 manual: 42.4 mpg (US) ... 18.0 km/L ... 5.5 L/100 km ... 51.0 mpg (Imp)
Doesnt the speedometer over reporting speed mean that fuel economy is worse than the MID is showing us? i use tires that are 4.9% larger in diameter than OEM. They are also 4.9% more circumference. Comparing my speedometer to phone mapping apps it is now accurate with these tires on the vehicle.
I calculate my mpg by using the odometer (not the speedometer).
miles traveled divided by gallons of gas used
If larger tires make my odometer reading off, my mpg calculations reading will be off, too.
I wouldn't know how to calculate my mpg using a speedometer reading?
I don't understand the logic of countries mandating speedometer readings being off. Seems stupid to me! Do countries mandate odometers readings?
The source for distance traveled will be the same, but how it is displayed is up to the gauge manufacturer. The time that a speedometer cable connected the speedmeter and odometer directly to a wheel axle, has far gone. Now the wheel rotation is feed to a microcontroller, which shows some number in the odometer (km or miles, is adjustable and doesn't matter, as it actually measures wheel rotations) and puts the speedometer needle in some position. Don't know how, maybe a rotary coil meter, or even a stepper motor, but there is anyway no direct connection between the sensor and the gauge. So the manufacturer can easily change the needle position a bit to meet the law, without being inaccurate on the odometer. (I once tested my odometer against Google Maps for a 250km drive, and the difference was less than 200m, which far better than I expected. Yet my car has been approved for use in the EU, so I know the speedometer is off by 5% or something)
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View my fuel log 2013 Space Star Cleartec Intense 1.0 manual: 55.7 mpg (US) ... 23.7 km/L ... 4.2 L/100 km ... 66.9 mpg (Imp)
How about the United Nations?
Some ghostdrivers don't believe in universally valid international agreements and regulations and think they have the liberty to write their own opposing "standards".
See: https://unece.org/fileadmin/DAM/tran...gs/r039r1e.pdf
Which comes first, the odometer or the speedometer? Depends on the instrument principle.
Strictly mechanical: chronometric as in the Smiths of England samples every 5 seconds (or so) the distance travelled and shows this as speed while the odometer registers the distance by gearing.
Electro-mechanical: distance by gearing while speed is a magnetic rotational force opposed by a spring on the needle shaft. Standard in USA until the advent of the computer.
Electronic: sensors count pulses on tone ring attached to either a wheel, ring gear or transmission output shaft for didtance while computer integrates pulses vs time to step motor speedo. Minimal mechanical (tone ring), major electronic.
Karl