I put a set of 19inch to my IS250 months ago! And I got twice taken pictures by the speed camera while I am sure I did not speeding at that time! I didn't get ticket on the first time and the second time was last night so I still waiting for call from the police... Now I am thinking would that be because I put a bigger wheels to my IS and it made some kind of different to the speed meter due to difference in tire size? My org setting was 16inch and the setting of my 19inch set is 19 235/35 at the front and 275/30 at the rear... as far as I know the 17inch was 225/45 and 245/45 so if I go two size up it should be 25 all around... so now I am 10mm more that I supposed would that be any effect to my speed meter?

Please help me out... Maybe I've been speeding the whole time!

 

If you changed your tire size, you'll probably have to take it to someone to get it adjusted. When you change the outer diameter of a wheel, it'll go faster with the same revolutions per minute.

 

you dont have to readjust the speedo as long as the new overall diameter is as close as possible to the old one. Some tire calculators even give you the +/-% change, if its a few percent it wont matter.

 

According to the tire calculator (http://www.miata.net/garage/tirecalc.html) the front wheels are about 1.2mph slow. So if your traveling 60mph, you're actually travelling 61.2mph. Not much of a difference there to be getting a speeding ticket though.

 

The cameras on the freeways here in Phoenix are set to take your pic when you exceed the limit by 9 or more mph, so here 1.2 mph could make all the difference in the world between a ticket and no ticket.

 

I say fight the tickets on that premise. For $50 (or whatever the ticket is) it's probably not worth it for them to fight you. Besides, speed cameras are just another form of taxation......just a really lazy form.

 

Good luck fighting the ticket with that argument. "Judge, I modified my car by putting non-standard size tires on it which threw off my speedometer. It's really not my fault. "

 

My point was that I would fight it on principle. I think speed cameras are a scam created by corrupt governments and endorsed by lazy police officers. In this country, when accused of a crime a defendant has a right to face his/her accuser. It takes justice out of the justice system.

That's why I think it is nothing more than a tax on the ignorant, just like state-run lottery.

 

Actually, here in VA, if you get your speedo calibrated and it was indeed off, the fine gets changed to "Improper equipment", which is NOT a moving violation and therefore has no effect on license points, insurance rates, etc. And, it doesn't even matter if it was due to a tire change or not...just as long as it was off.

The only unfortunate thing is that it costs a few bucks to get the calibration, as well as a whole day off from work to fight the ticket in court.

 

But you still have to pay the speeding fine, no? If you know your speedo is off, and you still speed, you are just as guilty of breaking the law. So other than skirting the points and insurance issue it still comes out of your pocket.

Everyone is entitiled to their opinion. Speeding is speeding. Whether you get caught by camera or a cop sitting in a car alongside the road doesn't make much difference in the scheme of things. You can still fight the ticket if you wish.

 

1km = 0.62mile so 1.2mph = 1.2/.62 = 1.9km so if I rolling at 80km/h on my meter that would be 81.6km still under the limit... the camera set off at 90...

I don't think I could fight the ticket since the law said I should not up size my wheels and tires...

 

You don't pay the speeding fine. The charge gets changed to improper equipment instead, which is just a flat-fee fine (like $50 or something plus court costs).

BTW, I'm pretty sure they only do this if your speedo shows close to the limit, but you were going faster (ie: in a 55 zone, your speedo showed 58, but you were really going 63). If you were going 85 in a 55, I don't think the speedo calibration is going to prove that you were *more or less* innocent.

 

How fast did you think you were traveling at the time? Was it below, at, or slightly over the posted speed limit?

 

Of course it is! They will tell you that speed kills, but the statistics don't back up that claim. Traffic accidents caused by speed alone are incredibly few in number. Its another money grab by the government. They will pull over law abiding citizens for going 30 in a 25 and ignore the crack dealer walking by.

 

I hope you guys realize the US laws will not apply to him...