Speedo out, tyre size?

[Lewis93]

So I started to notice every time I drive through a town that has a road sign telling you the speed you are travelling whilst I am doing exactly 30 on my clock it's always lower than 25.

With me travelling a lot I started to notice this through different speed zones, 30's, 40's etc and it's always incorrect by at least 5mph.

I was wondering if this was due to the tyre size? I currently have 215/45/17 eagle F1's on my car however my speedo corrector is very dodgy at the minute which will be getting replaced soon.

Any advice appreciated.

 

[dave7368]

tyres are the correct size so i doubt it will be that causing your issues...
most speedo's will be a bit out compared to sat nav..

 

[linh-ej9]

Download gps speed app for your phone for more accurate speed.

 

[OliverV]

Download gps speed app for your phone for more accurate speed.

Or use Waze!