Speed sensor not working properly?

[Tyaj7133]

Here's the issue on my '97 gsx: Whenever I am driving on the road, the mph seems to be 5mph faster than usual. How do I know? I tested it out while driving next to a buddy of mine and went past a mobile speed radar on the road. I am positive it's faster than the normal. I've never had an issue like this before. Could my speed sensor be not working correctly or is it something else? If someone could lead me to the right direction that would be very helpful.

 

[gofer]

What is your wheel and tire size?

 

[Tyaj7133]

What is your wheel and tire size?

It's currently sitting on 18x8 +37 tenzo r rims with 225/40r18 tires. I had 17s on them before but was doing the same problem with 5mph faster. So I thought at first it was a tire issue so I got different rims and tires. Still doing the same thing.

 

[gofer]

There's nothing wrong with your speedo as it's just a "guesstimate" anyway, mine's 3mph over with stock wheels, but this adds to the inaccuracy. Just forget that you know it's reading 5mph faster than you're actually going, that's what I do and I never get speeding tickets.

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[Tyaj7133]

There's nothing wrong with your speedo as it's just a "guesstimate" anyway, mine's 3mph over with stock wheels, but this adds to the inaccuracy. Just forget that you know it's reading 5mph faster than you're actually going, that's what I do and I never get speeding tickets.

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Okay, thanks for the attached photo with information. Yea it just bugs me when I am driving. 5mph is a big difference

 

[Firsts tuner]

I don't know about Wisconsin but Kentucky is notorious for turning the speed signs down a little. Took me a while to figure it out but everyone I pass around here is roughly 4 mph slower than my speed, according to my gps.