Thread: Variance between Gryphon and actual milage
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Old Sat, July 18th, 2009, 10:01 AM
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Jackpine Jackpine is offline
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Originally Posted by Savagetwelve View Post
Ok I was able to try out your sugesstions today with a GPS.
I set the TS to 2500 (+/-10) to see how it compared to GPS.
I noticed on constant acceleration and cruise speed the GR was reading about 1 mph vs. GPS.
When I punched it I nitice that the GR was 5-10mph more that the GPS until I reached a constant speed where the GPS then caught up
Why would this happen? Is the GPS just that slow to pick up the change in speed?
I think you just nailed it! The GPS updates it's information at regular intervals, and I imagine it's not the same for different models. Then, the processor inside the GPS has to perform some calculations to display your speed, and that takes time too. I would not expect it to react to abrupt changes instantly.

I think my Garmin hiking GPS updates on one-second intervals, and it's far more precise than my Ford Magellan GPS because the map scale it works with is more exact.

- Jack