How did you determine it was over by 4MPH, and at what speed?
Typically most manufacturers overestimate speed on their speedometers, and it gets worse the faster you go. Which is why you frequently see super accurate digital GPS speedos being used on car shows and record runs (even in ridiculously expensive cars).
My 8G was about 2-3MPH over at 50 IIRC.
Are the wheels on it stock? or have they been changed? That can add or lessen the problem depending on the final diameter.
thanks for the replies ( sorry I'm new to this forum I apologise if I'm replying in the wrong way)
just rough estimate I have used the usual road signs and my sat nav, my sat nav on previous car was spot on this one it's over and now that i have a dash cam the speed on that matches up with the others ones and still states that I'm 5mph over.
it's not a issue as such just wasn't to sure it was a problem I had or if others had it,
I would sooner it be 5mph over instead of 5mph under so suppose that's a bonus.
but looks like people have the same issue as I do so at least I know it's common .
as for the wheels their all stock and tyres are correct size.
im new to Honda's i have a 2008 1.8 ex what gen is that classed as
thanks again people if I am replying to posts in the wrong way could someone please point me in the right direction 🙂