I was thinking again.

[Willowbilly3]

My daughter has been bringing her Garman gps whenever we travel. It always knows exactly how fast we are going, plus it knows the speed limit where ever you are. And it cost $64. No why couldn't they just make a stand alone speedometer that runs off gps? It would be cheap and never need calibrating. Even take it from car to car. Instead of paying 4-5 times that for an electronic speedo.

 

[I-R-POPS]

They do make a gps speedo. They aren't cheap tho.
Around $400.00.
simple to install with no cable or magnetic sensor.

 

[Stroker McGurk]

I use my GPS as a speedo, since my actual one is so far out because I changed gears.

 

[billy]

my smartphone has a gps
i used it to see how far off my speedo was
and i also used my wifes speedo to make double sure.

 

[sneakysnake]

I use a gps too. You know they can make those speedos cheaper, I guess supply and demand.

 

[21willys]

I've used a app on my phone to determine rpms at certain speeds then just go off of tach.

 

[Sam_Fear]

They probably cost so much because of the chance of lawsuit. Advertising it as a speedometer adds liability and expectations of accuracy. Smartphones,etc. can just fall back on "it wasn't intended to be used that way".

...and people still buy them at that inflated price.

 

[Willowbilly3]

If they can sell a full funtioning GPS for $65, you would sure thing they could sell one that is just a speedometer for that amount or less. I do not have a speedo in my rod, maybe I need to get a gps??

 

[05snopro440]

If they can sell a full funtioning GPS for $65, you would sure thing they could sell one that is just a speedometer for that amount or less. I do not have a speedo in my rod, maybe I need to get a gps??

The thing is there is a lot more to a speedometer, and it needs to be calibrated. The GPS unit you move from car to car isn't calibrated for speed readings, although it is fairly accurate, the GPS speedometer needs a guarantee of a certain level of accuracy. You can barely buy an electric speedometer for $65, adding the GPS functionality on adds a bunch of cost. Plus the programming required for the speedometer not to crash to zero if the GPS loses signal for a brief second.

 

[Willowbilly3]

The thing is there is a lot more to a speedometer, and it needs to be calibrated. The GPS unit you move from car to car isn't calibrated for speed readings, although it is fairly accurate, the GPS speedometer needs a guarantee of a certain level of accuracy. You can barely buy an electric speedometer for $65, adding the GPS functionality on adds a bunch of cost. Plus the programming required for the speedometer not to crash to zero if the GPS loses signal for a brief second.

We had it on for both legs of a 1200 mile trip over the Rockies and it never missed a tick. Everytime I looked at it, it was dead nuts on with my car speedo. That's beyond good enough for me. And afaik you can't buy an electronic speedo for anywhere near $65.

 

[YBeNormal]

All I plan on doing is running my phone with a speedo app. Have a small bracket on the dash for it to mount to. It looks cool and it's accurate enough for me

 

[05snopro440]

We had it on for both legs of a 1200 mile trip over the Rockies and it never missed a tick. Everytime I looked at it, it was dead nuts on with my car speedo. That's beyond good enough for me. And afaik you can't buy an electronic speedo for anywhere near $65.

That was exactly my point about the electronic speedo. As far as the calibration, I'm just saying I think there might be extra testing and validation required when you're making instruments specifically to be bolted into the dash of a car.

 

[05snopro440]

I really like my Classic Instruments electronic gauges. They look analog and they're extremely easy to calibrate should it be necessary. Much cheaper than the GPS speedometers and a permanent solution. I used my GPS to verify it, but now if I want to run out I don't need to worry about packing my GPS or phone.

 

[maverickmk]

All I plan on doing is running my phone with a speedo app. Have a small bracket on the dash for it to mount to. It looks cool and it's accurate enough for me

That's exactly what I do. What app is that one you've got there?

 

[Willowbilly3]

But what if you need your phone to be a phone at the same time the speedo is very important? Like your gf texts while a cop is on your tail.

 

[YBeNormal]

That's exactly what I do. What app is that one you've got there?

Ulysses speedometer.

 

[YBeNormal]

But what if you need your phone to be a phone at the same time the speedo is very important? Like your gf texts while a cop is on your tail.

Just tell home it's your heads up display

 

[maverickmk]

Ulysses speedometer.

Just downloaded it! Thanks

 

[bob w]

I built a bracket into each of my cars and I move this GPS to whichever car I'm using. Speed is shown in the large circle. Bright sunlight is a problem in the roadster however.