Has anyone else noticed.....
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In my line of work analog is inaccurate and digital is more accurate.
Point I'm trying to make it that it all boils down how well the system is calibrated.
I think this is something you need to take up directly with Chrysler. I would honestly think that both should be connected to the same point of reference, thus showing the same speed. A 3mph difference could become a big deal.
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Hook up an external gps and see what you get for speed? Compare the numbers and report back. If not, I'll give it a shot after work.
Sent from my iPhone 4S
Sent from my iPhone 4S
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I think the allowances in factory speedometers are something like 10% error; crazy I know, but you can get out of a speeding ticket but showing this fact in court.
My guess is that this is standard crysler "quality". The variance would depend on how each gauge is both measured and calibrated. They are probably the same input, just sent to different analog and digital displays with associated gauge errors (its all OHMS on the CAN BUS). You'll never really know exactly how fast you're going unless you do the test Mongoose says. Get a quality hand-held GPS and try and maintain constant speed on yoru reedout, then compare to see the error.
The error may not be linear either, in other words, it might not be exactly 2mph at all speeds, it might be a function of how much speed you have, which means you'll have to plot the errors at different speeds to find the slope of the graph.
I know I know, this is getting way too mathematical. I do this for a living as a functional check pilot, lol.
My guess is that this is standard crysler "quality". The variance would depend on how each gauge is both measured and calibrated. They are probably the same input, just sent to different analog and digital displays with associated gauge errors (its all OHMS on the CAN BUS). You'll never really know exactly how fast you're going unless you do the test Mongoose says. Get a quality hand-held GPS and try and maintain constant speed on yoru reedout, then compare to see the error.
The error may not be linear either, in other words, it might not be exactly 2mph at all speeds, it might be a function of how much speed you have, which means you'll have to plot the errors at different speeds to find the slope of the graph.
I know I know, this is getting way too mathematical. I do this for a living as a functional check pilot, lol.
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As a side note, on my WK1 my scan gauge would always match my garmin gps for MPH readouts. The scan gauge reported back a digital speed from the can bus.
Sent from my iPhone 4S
Sent from my iPhone 4S
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Heres what I gathered on a quick test. Using my iPhone 4S with the garmin app i watched vehicle speed compared to what the gps reported.
From previous times I know my iPhone reads the same as my stand alone garmin 850 (IIRC on the model number, it was top of the line when I bought it a few years back).
Anywho, the iPhone matched the digital display for my MPH readout.
As for the analog gauge here's my opinion. Parallax!
http://en.m.wikipedia.org/wiki/Parallax
Basically, I can make the analog speedo read quite different depending how I look at it and from what angle.
I'm sure it's accurate though.
Thoughts and opinions? But I gather both read correctly.
Sent from my iPhone 4S
From previous times I know my iPhone reads the same as my stand alone garmin 850 (IIRC on the model number, it was top of the line when I bought it a few years back).
Anywho, the iPhone matched the digital display for my MPH readout.
As for the analog gauge here's my opinion. Parallax!
http://en.m.wikipedia.org/wiki/Parallax
Basically, I can make the analog speedo read quite different depending how I look at it and from what angle.
I'm sure it's accurate though.
Thoughts and opinions? But I gather both read correctly.
Sent from my iPhone 4S
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In my C6 Z06 My HUD (Heads up Display) shows the same speed as my GPS Speed App on my phone, while my Analog Speedo will be 2-3mph off. This is normal.. Digital and Analog Speed sensors are two very different things to Calibrate. Who here remembers the old British cars with Jumping Speedometers and Tachometers?
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Good test and results. Parallax is a very real issue with analog gauges, no doubt about it.
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