Which is accurate ? My car's speedometer or TomTom ...?

[ofiaich]

Hi!

I was wondering because I notice, that my TomTom Navigator 5 on my Tungsten T3 shows the speed as being 37 miles an hour, but the speedometer in the car shows 40 miles per hour.

I am thinking the Sat Nav must be more accurate than the car for a number of reasons. One reason beeing that the car has had it's first MOT and mechanical things wear out !

Any comment always welcomed !

Ofiaich

[mikealder]

Try a search on the forum, this question has been asked hundreds of times! - in sumary the GPS is more accurate than the vehicles speedo, but GPS derived speed accuracy will degrade when cornering or climbing/ decending (still more accurate than most vehicles speedo's though) - Mike

[ofiaich]

thanks mikealder!

I did do a search using " gps speedometer accuracy " and "more accurate gps speedometer" and " speed accuracy "but the return had many many other titles.

I will think on how to refine my search.

Ofiaich

[mikealder]

Try GPS AND speedo AND car as the search and on the first results page are at least five entrys covering this topic, the search fuction does take a little getting used to - Mike

[ofiaich]

mikealder!

thanks again! Enjoyed exploring those ! Very interesting!

Ofiaich

[bluenose67]

hi
im a lorry driver and my sat nav speed shows exactly the same speed as the lorry but if im in the car it is 4mph slower than the car i have spoke to a couple of other lorry drivers and theirs is the same with the car 4mph faster so i think car speedos are set higher than they actually are

[JockTamsonsBairn]

[bluenose67]

yes the speedo and tacho are connected which have to be very accurate as you can be fined for any illegal information on tachgraph

We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?.
Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!