Hi Euan the Road Angle updates its speed every 0.8 seconds.

Also at Woodbridge last year it was giving out the same speed reading as the Racelogic Driftbox within 1mph.

I use the Road Angle as my Speedo, the only problem is, if it drops down to 2 satalites (like up in the Highlands here) it tends to display randon numbers!

S.