Thread: Garmin Nuvi Accuracy
05-05-2010, 06:54 AM #1
Garmin Nuvi Accuracy
I recently purchased a Garmin Nuvi GPS and decided to use it to validate my max speed on my Ultra 260X. To make a speed run, I reset the max speed to zero, place the GPS in my glove box and then go for about a mile run. While doing the run I look at the digital rpms and make note of the most constant rpm value. At the end of the run, I pull out the GPS and check the speed. You may ask, "Where is Phil going with this thread?" ... OK, using this procedure, is the Garmin Nuvi dead-on balls accurate? I know when I am sitting still at idle, the GPS sometimes reads 1.8mph, 2.6mph and 3.8mph. I know this is wrong because I am not moving at all... but what about when you are going fast... could there be a 3-5mph max speed error? I called Garmin yesterday and the tech rep said, "If the GPS says 79.6mph, you are going 79.6mph plus or minus 2/10s. It can never be 5mph off!"
Please relate your experiences?
05-05-2010, 08:26 AM #2
- Join Date
- Mar 2008
I have the same GPS and get the same thing going out of a wake area. Its good to go bud. All of them do that.
05-05-2010, 08:35 AM #3
the issue is your GPS is setup for Land use, you need a handheld model for watercraft.
i also have a NUVI and two handheld units.
05-05-2010, 09:38 AM #4
05-05-2010, 09:57 AM #5
05-05-2010, 12:15 PM #6
05-05-2010, 12:39 PM #7
- Join Date
- Jul 2007
- near Toronto, Canada
The GPS needs a clear view of the sky over a wide arc to provide maximum accuracy. And it needs strong reception of those satellite signals.
Bouncing around in the glovebox, with your body partially blocking the satellite signals, can limit GPS position accuracy.
With reduced position accuracy, the maximum GPS speed calculation can also be inaccurate. The average speed displayed may jump around, but will mostly be accurate.
Watching the current speed number displayed will give you a better idea than relying on the GPS log of the peak speed displayed. That peak number might have been incorrect.
You have no way of verifying whether the peak recorded speed matched the continuous top speed over many seconds, unless you watch the display as you ride. Some GPS have the ability to analyze a stored track afterwards, and show the speed over many small segments.
Have a look at this;
05-05-2010, 12:42 PM #8
05-05-2010, 02:23 PM #9
05-06-2010, 07:23 PM #10
there are many things affecting gps readings......current (water speed-flow) is one of them.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By jetskidj in forum Sea Doo Open DiscussionReplies: 42Last Post: 05-12-2010, 04:31 PM
By MPower in forum 4-Tec PerformanceReplies: 5Last Post: 02-03-2008, 05:45 PM
By mirzar1 in forum 4-Tec PerformanceReplies: 10Last Post: 11-04-2007, 10:17 PM
By john07ex in forum Kawasaki PWC Performance (4-stroke)Replies: 11Last Post: 08-04-2007, 03:34 PM
By USS RXT in forum Sea Doo Open DiscussionReplies: 5Last Post: 09-01-2005, 06:27 AM