gps and speedo comparison
Stellar HDF Member
Joined: May 2008
Posts: 2,588
Likes: 9
From: Sunny Southern California
Here in So Cal we have a lot of radars in school zones that post your speed your traveling. My 07's speedo always showed faster than those and my GPS by 5+ mph! When on a road trip with a buddy last spring (riding side by side, him on a 06 SG) I got way better gas milage than he did cause I'd always ridden a several more miles between gas stops! LOL! All was good once I changed to 18" wheels (from stock 16'"s) front & rear.
Advanced
Joined: Sep 2010
Posts: 86
Likes: 0
From: Marquette, Michigan
Some GPS will give you speed over the ground, which is not the same as a road that is not perfectly straight. In other words the gps may read your route from point to point which are spaced out and are not the same as your bike following the curves in the road. The GPS will not match the speedo at all times because of this.
Outstanding HDF Member
Joined: Mar 2005
Posts: 2,913
Likes: 8
From: Darlington WI.
Ive checked 3 different GPS's and all readings were identical at speed. One was a Tom Tom 1XL one was a Garmin 1490 and the third was a hand held unit of my boss's. The speedo's on both my 87 and 2011 ultra read 3-4 mph faster then then the GPS's
Road Captain
Joined: Jun 2010
Posts: 609
Likes: 14
From: Mount Airy, MD
Mine is 3 to 5 mph over depending on the speed. Just think how many miles are on your ODO that you really didn't ride!
I have a PowerVision tuner but I can never seem to find the time to correct the issue.
I have a PowerVision tuner but I can never seem to find the time to correct the issue.
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Road Warrior
Joined: Mar 2011
Posts: 1,456
Likes: 132
From: Deep South, Louisiana
Your GPS should be accurate. All vehicle manufactures set the speedometer 2 miles faster than true speed to give a safety margin. Then as your tires wear it will change slightly more. Next time you go to change out set of tires see how much its off. When you put the new tires it should be back to 2 mph off. This is with the OEM sized tires.
