I have been using the traffic app Waze for accident reports and updates for my daily commute and have noticed a 5% difference between the GPS mile per hour and the speedometer MPH. example when the speedometer says 60 the GPS reports 56-57. about 5%.
Has anyone else noticed this? Is this something Honda has done on purpose?
The tires are the correct size and are nearly new Bridgestone Turanza, so I am thinking that the rotational diameter is close to what it was from the factory.

 

I don't have a good answer to why you have a 5% reduction in speed. I don't know what the error is on GPS for determining speed, but you should be able to find that information on the web.

Another way to measure you speed is to set the cruise control on your car and time yourself between mile markers on the interstate.

 

See this thread for some info.

https://www.hondaaccordforum.com/for...oo-fast-55679/

 

Good thread you gave him here..Thanks to you 2 mods

 

My 92 Civic DX Manual car was the same way as I remember, The speedo read 60 and I kind of know I was going closer to 55.
I am going to use the Trip odometer and check aginst the GPS for the total mile of a round trip commute and see if there is a difference in the total results.