Flamedx4

IF the speedo was accurate with stock tires, here's what it would read now:
Indicated 35mph would actually be 38.75
Indicated 31.6mph would actually be 35.

For it to read 35 and actually be going 51 you would need 40" tires.

And it will make no difference to the Judge whether the tires affected the speedo or not - WHY she was speeding doesn't alter the fact that she was speeding and you(she) are responsible for the equipment on the car you drive. IN other words - you can't prove it's not your fault.

lee

https://www.yotatech.com/forums/show...ghlight=speedo

theres some info in this thread i made when i had this same problem.

Flamedx4

Probably won't help with the court - other than to debunk the cop IF he says he only pulled her over because he thought her tires were oversized. Unlikely though, since he has her on radar.
But you CAN prove to HER her it's not the tires fault (not your fault in other words..lol ) and that she was indeed speeding....

Your speedo error should be 5% (based on the tire change 28s v. 31s)
35mph indicated + 5% = 38.75 actual speed.

callmej75

I understand she was at fault to a certain degree...but for future issues I want to know what my actual speed is in case I gotta back down a little because I hate tickets! Plus the courts might say ok...now you know your speedometer is a little off...compensate for it or get it recalibrated or suffer more tickets! Instead of going in blind and pleeing guilty...or no contest. Its all up to the judge...and trust me...I've saw plenty of them to know if they are having a bad day then they will stick it to ya! In small towns like this...everybody knows everybody so maybe if the cop sticks up for it a little...might be a lesser fine. I guess I'll go down to this garage here this weekend and get it read at different mph and see how much I am off each time and figure up my variable and repost here with my readings.

Flamedx4

There are tons of documents on the web for this stuff, just google for it.
Here's some: http://www.thecarconnection.com/Enth...277.A3527.html
http://www.vclassics.com/archive/speedotip.htm


If you don't want to figure it out -
Here's a percentage calculator for the math impaired. http://www.webcalc.net/calc/0787.php

Here's a tire size/ speedo calculator. http://www.paspeedo.com/calculator.htm
The tire diameter database they use doesn't work very well. Be aware of it when puttting in your numbers.

Here's a calculator for timing mile posts to determine actual speed. http://www.bryanf.com/pc/calc/chassis/pcspeedo.htm

There are tons of documents on the web for this stuff, just google for it.

bruzer1123

Hey ask for all the paperwork when you go to court. Can't remember what it is called to file the motion to get said paperwork...but it should include stuff on whether the cop is up to date on using the radar, radar calibration, etc, etc. The odds are there that one of them is out of date. Heard this on the radio....guy wrote a book about getting out of tickets. Hope this helps...

2ToyGuy

It's called a "Motion of discovery". Essentailly means they have to give you everything you need to make your case, whether they were going to use it or not in their case...