Speedometer Not Matching with GPS Speed

[RoLyMa27]

Is it just me, or are y'all WAY over-thinking this? Don't sweat the small stuff gentlemen!

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[L8apex]

Ah, I see your point. But it would come down to where the source of the error is. Is it in the "Signal A" or is it in the algorithm to compute the distance or speed. If it is in one of the algorithms, then one can be off while the other is correct. If it is in the signal A, both speed and distance would be off.

It's an intentional buffer on the speedo and it's in pretty much all Ford vehicles, you'll also see this in other OEMs.

And before people say what about emissions and fuel economy tests - the speed for those is determined by the speed of the chassis rolls, not the speedometer.

 

[P52Ranch]

I think for liability reasons, most manufactures produce cars with speedometers that read optimistically. Certainly Ford does. My Boss 302 reads 80 when it is really doing 77.6 mph.

That being said, the odometer reading may not be optimistic compared to the speedometer. It's not like the old days where the speedometer and odometer are both driven by a cable off of the transmission. You would want to check your GPS for actual miles travelled against the odometer.

 

[2021badlands bronco bob]

I usually have Waze running whenever I am driving. I also have Waze display the GPS speed. I typically see a slight difference between the GPS speed and the vehicle speedometer; however, on the Bronco, it seems excessive.

At 80 MPH on the Bronco speedometer, Waze displays between 77 and 78 MPH. This equates to approximately 2.5% more miles being logged on the odometer than actually driven. This would end up in me being covered for 1200 miles less on my 60,000 extended warranty I purchased.

Needless to say, this will be on my list of issues to resolve when I take the Bronco in for warranty issues.

Before people start getting super worked up over the issues I am pointing out, let me say (again) this Bronco has surpassed every expectation I have had for it. To me, these issues are minor and easily fixable when Ford and the dealer are given the opportunity to fix them.

Is that a tin hat I see on your head

 

[Erock]

Last I checked, 2.5% of 60k was 1500 not 1200... but I’m not up on the common core stuff, so I’m probably lost.

 

[NotApplicable]

Speedos often run 1-3% high, and it is not directly linked to the odometer reading

 

[redstarn]

I tend to agree with the bigger tire theory ?

 

[Werkedperformance]

""The difference between actual speed and the speed dial tends to get noticed more with German cars because their speedometers are designed to never report a speed lower than actual speed. European law (ECE-R39) says speedometers cannot show speeds less than the actual speed, and they must never show more than the 110 per cent of actual speed plus 4 km/h. So, under those rules, a car could be moving at 100 km/h, but the speedometer could legally display as high as 114 km/h.

But, generally, most speedometers exaggerate speeds, says Wall Street Journal columnist Jonathan Welsh. "Industry officials have said speedometers are set 'optimistically' to give drivers an inflated sense of speed (and help them avoid tickets)." Welsh says. "GPS devices record distance over time without the effects of mechanical variables and thus tend to be more accurate."""

source: https://www.theglobeandmail.com/glo...driving-as-fast-as-you-think/article11487709/

 

[airishfan]

What makes you think that Waze gps speed is more or just as accurate as your cars computer system that is literally monitoring your car? I have always noticed Waze is off 1-2 mph

I was about to ask the something ,I never used this Waze thing but I think the vehicle computer be more right .

 

[airishfan]

I tend to agree with the bigger tire theory ?

bigger tire theory only works if he changed to bigger tires then stock

 

[Dads_bronze_bronco]

Would be better to get on the highway and time say two miles by the mile posts with cruise control engaged. Maybe take three separate measurements.

 

[STLDAVE]

I usually have Waze running whenever I am driving. I also have Waze display the GPS speed. I typically see a slight difference between the GPS speed and the vehicle speedometer; however, on the Bronco, it seems excessive.

At 80 MPH on the Bronco speedometer, Waze displays between 77 and 78 MPH. This equates to approximately 2.5% more miles being logged on the odometer than actually driven. This would end up in me being covered for 1200 miles less on my 60,000 extended warranty I purchased.

Needless to say, this will be on my list of issues to resolve when I take the Bronco in for warranty issues.

Before people start getting super worked up over the issues I am pointing out, let me say (again) this Bronco has surpassed every expectation I have had for it. To me, these issues are minor and easily fixable when Ford and the dealer are given the opportunity to fix them.

Tire pressure can change the effective diameter of the tire slightly, which changes the rolling circumference, which would change the true speed. Try lowering the tire pressure a few pounds.

 

[rdass623]

get on the interstate and time yourself between mileposts. that way you will be able to figure out which is accurate...

 

[Jason F]

I usually have Waze running whenever I am driving. I also have Waze display the GPS speed. I typically see a slight difference between the GPS speed and the vehicle speedometer; however, on the Bronco, it seems excessive.

At 80 MPH on the Bronco speedometer, Waze displays between 77 and 78 MPH. This equates to approximately 2.5% more miles being logged on the odometer than actually driven. This would end up in me being covered for 1200 miles less on my 60,000 extended warranty I purchased.

Needless to say, this will be on my list of issues to resolve when I take the Bronco in for warranty issues.

Before people start getting super worked up over the issues I am pointing out, let me say (again) this Bronco has surpassed every expectation I have had for it. To me, these issues are minor and easily fixable when Ford and the dealer are given the opportunity to fix them.

At Highway speed’s Waze adds about 10 mph to my speeds. Wife notices and thinks I’m doing 90. Only 80.

 

[WuNgUn]

I usually have Waze running whenever I am driving. I also have Waze display the GPS speed. I typically see a slight difference between the GPS speed and the vehicle speedometer; however, on the Bronco, it seems excessive.

At 80 MPH on the Bronco speedometer, Waze displays between 77 and 78 MPH. This equates to approximately 2.5% more miles being logged on the odometer than actually driven. This would end up in me being covered for 1200 miles less on my 60,000 extended warranty I purchased.

Needless to say, this will be on my list of issues to resolve when I take the Bronco in for warranty issues.

Before people start getting super worked up over the issues I am pointing out, let me say (again) this Bronco has surpassed every expectation I have had for it. To me, these issues are minor and easily fixable when Ford and the dealer are given the opportunity to fix them.

Every car on the street is conservative like this... Or just the Bronco. This is a well known fact since....? The dawn of GPS....?

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