Running Waze. I hope Google doesn't ruin it.

[gypsyman]

I have been running Waze for a month now. For those who don't know, it is a social navigation app in the play store. I am impressed. Real,time reporting of police, accidents, hazards etc. Google looks to outbid Facebook to the tune of 1.3 billion to acquire it. I have noticed that the GPS speed above 50 Mph is 2 mph slower than my vehicle display. Which one is correct? Anyone?

 

[MixMasterTang]

Find an open highway, set cruise control at 60 and use a stop watch to time yourself going between mile markers.

 

[jagec]

Speedometers often read high, particularly in Japanese cars in my experience. The GPS is likely to be more accurate. Use the stopwatch method as previously mentioned to confirm.

 

[Markbnj]

I agree with Jagec that the GPS is more likely to be accurate, over time. The more samples it has the more closely it can calculate your speed over the ground. In short bursts the speedo will probably be more accurate. It's also been my experience that the speedo and GPS don't line up. In my case the speedo reads 2-3 mph higher than the GPS.

 

[Gerle]

I too have noticed the two mph difference, when using speed readouts from roadside radars my speedometer seems accurate. I have also heard others mention the two mph in conjunction with Waze.

 

[jagec]

when using speed readouts from roadside radars my speedometer seems accurate.

German/American car by any chance?

 

[Gerle]

Nissan Altima 1999, I think US with lots of Japanese parts.