Speedometer shows +10%

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Klubbrik

New member
Joined
Sep 29, 2016
Messages
4
Hi,
I'm not ovner of à Nissan Leaf yet, but use to rent in Gothenburg, Sweden.
I found that compared to my Tomtom GPS, the speedometer in the Leaf's shows 7-10% too high speed.
About the same in two different cars.
I know that most speedometers shows a little bit to much, but maybe more in the range of 2-5%.

Anyone else that has noticed this?

Next month I will start My Leasing of a new Leaf (30kWh Techna), then we will see if it is the same ....

/Klubbrik
 
Yes I find that to go 40 mph actual I have to drive at about 43 mph indicated. Mine now has 17,000 miles on it and I am hoping that with new tires it will read more accurately as the current look a tad more worn than they should be at this many miles. I expect about a 5 mph deviance from speedometer readings with new tires compared to worn to end of life. Tire diameters diminish with every mile you drive.
 
Klubbrik probably has a LEAF "S" model. My speedometer read about 5% too fast with the 16" tires/wheels that came with the car. Since upgrading to 17" tires/wheels, my speedometer error is around 0.5%. Nissan seems to use too low of an aspect ratio on the 16" tires. You can increase it one size and reduce your speedometer error by about 3%.
 
Assuming you have a center display there is a service menu that will let you adjust the speedometer +- 2.5%. After that you'll have to buy different tires to address inaccuracy.

Find the lowest revolutions per mile offered as an OEM tire (17" vs 16" or whatever is offered there) and find a tire that has 2% or so less revolutions per mile on the spec sheet.

Change the calibration on the center screen and change the tires and you can get it pretty close to accurate.
 
There may be a more "sinister" explanation for speedometers in Leaf always running high. A vehicle without GPS "calculates" the speed and hence the distance from wheels revolutions per second and tires diameter. By programming the speedometer to read high (mine is also high by approx. 8 percent) Nissan achieves an overstated battery range, as well as records a higher driven mileage. If it is so, and the error is intentionally programmed to be on the plus side but within the allowed rang of +/-10%, it becomes very suspicious in the VW Emissions Programming sense. Think of leasing a vehicle with a limited mileage? Are you being taken advantage of? I may be mistaken, need your thoughts regarding this matter...
 
Call me cynical but that's always my suspicion. Manufacturers clocking their speedo's too high because it makes warranties expire prematurely, without anyone noticing.

I've owned several vehicles with high speedometers compared to GPS. I've owned none that were too low. If it really is just an accident, it's awfully fishy that it's an accident in one direction only.
 
I used the programming feature noted in an earlier post to correct the speedometer on the 2011 in combination with inflating the tires to 44 psi. It was then within 1 mi/hr. The odometer actually indicated slightly less than actual distance travelled with tires inflated to 44 psi. Although the 2015 has the same programming capability, changing the setting over the full +/- 2.5% programming range has no effect on the speedometer. With the tires inflated to at least 44 psi, the speed is within 1 or 2 mi/hr (1 mi/hr high from 2 to 60 and 2 mi/hr high above 75). The odometer is accurate over the entire speed range as long as tires are inflated to at least 44 psi.
 
BenTheRighteous said:
Call me cynical but that's always my suspicion. Manufacturers clocking their speedo's too high because it makes warranties expire prematurely, without anyone noticing.

I've owned several vehicles with high speedometers compared to GPS. I've owned none that were too low. If it really is just an accident, it's awfully fishy that it's an accident in one direction only.
How much speedometers are off by are NOT always the same about by which their odometers are off by.

There are also reasons why they're off. See links at http://www.mynissanleaf.com/viewtopic.php?p=177842#p177842. The Priuschat link may no longer point to the right post due to a software change over there. You'll want to look at post 17 at a few that follow.

Also, what's displayed by the speedometer and odometer can be affected by how worn the tires are. From https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=177:
When the GPS indicated exactly 100 miles had been traveled while the vehicle was equipped with new 12/32" deep tires, the vehicle's odometer registered 99.4 miles. When the vehicle was then equipped with another set of the same tires shaved to 2/32" of remaining tread depth, the odometer indicated 101.0 miles. While the 100-mile test distance didn't change, essentially the vehicle's odometer overstated the distance traveled by about 1.5% when equipped with the worn out tires.
And, there can be differences in the # of revolutions per mile on different makes and models of tires even though they're all the same size. They list 3 tires of the same size: the OE tires on the 08 Prius vs. 2 others and the revs per mile range from 855 down to 843.
As shown above, there are slight differences between the tires' published diameters, tread depths and tire revolutions per mile. However, if a tire rolls fewer times per mile than the tire it replaces, the vehicle will again actually be traveling farther than is indicated by the odometer. Calculating the influence of the different tire specifications on the vehicle's odometer would indicate the Yokohama AVID TRZ would travel .6% farther than the Goodyear Integrity, while the General Altimax RT would travel 1.4% farther.
 
Wow - learned something new today, thanks for the informative link.

Seems like in a nutshell, the behavior I've noticed is real, but my suspicion of underlying cause was wrong. The manufacturer's hands are actually tied, somewhat.
 
I'm reading the links provided and the articles keep saying "speedometer can be high, odometer is probably accurate." I have my doubts.

Depending on which vehicle I take to work, the mileage is either 16.4, 16.6, or 16.9 miles over the exact same route, with the fairly-new tires inflated to exactly the maximum pressure printed on the sidewall. If Google Maps can be believed, 16.4 miles is the correct distance.
 
You are absolutely right. The odometer does not go by the GPS speed (not all models are even equipped with GPS). The only way the odometer "knows" the distance is by the number of wheel revolutions and presumed diameter of the tires. Since over the life of the tires their diameter only goes one way, decreases, it would be logical for the manufacturer to program the speedometer with an average presumed diameter of the tire, not the largest (new) or even more. Since all reported descrepancies seem to go only one way closer to allowed +10 percent, it raises a huge suspicion. Think of millions of dollars people overpay for excess mileage in the end of their leases, think of premature warranties' expirations, think of overstated battery distance capacities/ EPA mileages, etc. Do we have a case of possible programming fraud similar to VW "clean" diesel scandal here?
 
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