My 2003 Ultra agreed with the Garmin, have not checked the 2009 yet.

 

My current bike and the bike I had before this both read 3 mph FASTER than my true speed (determined by my GPS). This is at 70 mph. IE if speedo say i'm doing "75" I'm actually only doing 72 mph.

 

Due to manufacture's tolerances (or lack of), they all, bikes, cars, trucks etc, always play it safe and error on the consumers safe side. I used to be in a business that dyno tested hundreds of speedos for accuracy, never seen one that indicated higher then actual speed, always lower.

 

When the Garmin GPS reads 70

my 08 Street Glide read 73
my 09 Street Glide read 73
(if I was doing 70 on my Street Glide speedo, I was actually doing 67)

my Chrysler Aspen reads 70
my wife's Buick Enclave reads 70

I changed the rear tire on my 09 to a 17" 200/55 and now it reads 70

 

04 egc is spot on with two different garmins Zumo 450 and nuvi 250. If gps says 70mph my speedo says 70. In 100 miles the odometer will be within 9/10ths of a mile compared to either gps.

 

Got about the same thing here. 70 on the HD speedo is about 67 on the GPS

 

Really?! I've never seen one that indicated lower than the vehicle speed. Invariably vehicle speed is slower than indicated speedo speed on all vehicles I've ever riden and driven.

 

Speedo at 80
Garmin at 76.5

 

Oops, I stated it bass ackwards, you are right, I agree. Thanks for the correction.

 

So, does the speedo running faster than I'm going mean that time goes by quickly???