GPS, how accurate are they?

[Greg_D]

as far as tom tom and garmins, does any1 really know how accurate at mph they are? my speedos off and i use this lol.

 

[JonBeast]

The MPH seems right on with mine...I drove past one of those radar speed tracking things on the highway yesterday, and my GPS and the Radar speed were the same.

I have a Garmin.

 

[duh09]

I have to do the same thing. Works great except for when I take off faster than my GPS can keep up

 

[Greg_D]

ok cool, ya it def has a delay. my truck and car speedos are off if my tom tom is accurate. damn tire sizes and gears

 

[OnyxCobra]

I have a Garmin and I have no reason to think the MPH is off with it. Whatever technology it's using to calculate my MPH is probably a lot better than whatever our cars have in it lol

 

[Greg_D]

haha didnt think of it that way!

 

[eliyarbrough]

I am fixing to buy a Garmin just for this feature.

 

[Passenger]

Most speedos on a GPS are within 0.1mph I'm fairly certain. If you've regeared your car, or changed tire/wheel size your factory speedo is off without a Speed Cal, and/or changing the speedo gear on the tranny

 

[joekd]

Top speed memory on the GPS is great. I use it all the time to clock my motorcycles, go kart and such. Just strap the Garmin down, reset the memory, make your wide open run then check the top speed at your leisure once I am home again.

 

[Cookieman00x]

^^^ Ive done the same think... I believe it to be close to the real speed

 

[Inspector13]

My Tomtom reads slow on all my cars by 2 mph. So when I'm doing 60 it says I'm doing 58. The Garmins may be better at the whole mph thing but my Tomtom is slow by 2 mph. Although I've never gotten pulled over for doing 60 according to the GPS (actual 62 mph).

 

[KWClutch]

I have a Garmin and it's always dead on. I use it more than my Speedo.

 

[sn95gtvert]

gps fetures on phones have this mph deal too.

my friend used his but i think its wrong, he said with 245/45 tires and 3.73's he was doin 80 at 3k in 5th.

by my math (use of a speed calc) with my 275/45 and 3.73's 3k in 5th is 91mph

 

[RideThePONYgt]

atleast your guys speedos WORK lol mine says im going zero

 

[sn95gtvert]

at least your not gaining any miles on the clock.

 

[RockstarMentality]

atleast your guys speedos WORK lol mine says im going zero

SAME lol. hopefully the shop fixes that when they put the T-56 in.
back in the day when it worked, the Garmin would always say just a little more than my speedo. I drove 45 mins to work every day, id set cruise at 100 on the dash and the GPS would say 107. not noticible if you're not breaking the law