Speedo way out of whack

[Buurin]

Yesterday I drove my dad for another buy-to-return run and brought my GPS and DashDyno along just for fun. I don't like what I see on the 401.

Speed reported by GPS: 98.5km/h
Speed reported by OBD2: 100km/h
Speed shown on the speedo: some 105km/h!

Can anything be done about it? It's a 97 4cyl auto, mostly stock except that K&N drop-in. Nothing was replaced in those areas.

[95PimpingCamry]

Do you have the stock or aftermarket wheels? A different wheel size will throw things off.

Also your speedo will be a little off no matter what. My speedo will read 70 MPH while my GPS says 68 MPH.

[Buurin]

Originally Posted by 95PimpingCamry

Do you have the stock or aftermarket wheels? A different wheel size will throw things off.

Also your speedo will be a little off no matter what. My speedo will read 70 MPH while my GPS says 68 MPH.

Stock. Although I wanted to put alloy 15s on that thing.

[CamBOT]

Believe it or not, I took off my hubcaps and my speed is off by +2 km/h. No joke!

Sup Piggy!

[desentrix]

Mine's off by 2-3 according to the GPS.

['_']

I have the same problem. The faster I go, the more inaccurate my speedometer is according to my GPS. I think it reads 4-5MPH too slow at 75MPH. My tires are the same size as the stock ones too.