Downsizing tyres affect speedo readings?

[Kooler]

I changed my profile 55 tyres to profile 50 tires.I know that speedo readings would not be accurate,BUT would it under or overstate my actual speed or mileage readings?If so by how much is the difference?Say if my speedo shows 100km/hr,wat would be my actual speed?

 

Likewise when my odometer reads 100KM,wat is the actual distance I covered?

[Calfskin]

Hi Kooler.

 

You can find all the answers on this sticky.

 

http://www.mycarforum.com/forum/Aftermarke...ulator_P729080/

[Octopus]

Yes, your actual speed would be higher than your speedometer reading if you change from 55 profile to 50 profile, while maintaining your original rim size and tyre width.

[Simonleng]

isit? my lower the profile.... but

 

when i am 100km/hr my gps state 97 nia... then i put the gps on another car with stock tyre, 100km/hr the gps show 100km/hr

[Fitvip]

I think it is the opposite! Speedometer reading higher than the actual speed!

[Kooler]

Wat abt odometer reading?Would it overstate or understate if lets say my odometer shows 100km travelled wat would be my actual odometer.

[Orablue]

if ur speedo is correct, then the odo should also be correct.

 

if not correct, then look up the sky and see if there's any UFO near by...

 

then look at the rear view mirror and do a head count... hehe

[Octopus]

Oh ya, should be speedometer showing higher than actual..

[FGY7022]

did you increase you rim size while you reduce the profile?

[Kooler]

nvr change rim size,using 15' correct profile should be 55 but I used profile 50mm on purpose

[FGY7022]

hmmmm... then like that your overall size of your wheel will become smaller lor... so...if i am not wrong, if your meter shows you traveled 300km, you are actually travelling lesser than that....

 

is it har?? a bit luan liao.... but i know the distance traveled would be diff lor...

[Easyfil2000]

but its only abit right