[persian54]

Ever since I hooked up a VBOX to my car, I've noticed my Speedo is always a good deal lower than the VBOX reading

From my understanding, the VBOX reading is more accurate and is true ground speed...

Thus, let's say you're going 85mph (speedo) on the freeway and a cop is behind you and pulls you over cause he paced you at 75

If you had Vbox hooked up, can you argue that it was indeed only about 70-71mph, which is better than 10+ over? and from what I've heard, judges dismiss cases where the person is going less than 10mph over the posted speed limit

Just a thought/idea..

[jpsum]

it's still your words vs the officer's. VBOX or not, it doesn't make a difference.

[E90SoFlo]

From what I have been told its 7MPH and the speedo is set 5 over from BMW.

Get an attorney, they will get you off pretty easy.

[iBoost]

I doubt it will hold up.. They might think you manipulated the data..

[persian54]

I mean, I don't have a case coming up or anything so I don't need a lawyer etc.

I was just curious.

I've heard of many cases getting dismissed because the office didn't have a radar printout so the lawyer claimed human error or something (again this is just what I've heard. I've never disputed a ticketed before myself).

VBOX data is (again from what I've heard) extremely difficult, near impossible to manipulate. That's why it's used as a way to find 60-130 times etc.

[Bobble]

Since I've had the pleasure of spending too much time in traffic court the last 5 years the only people I've seen dispute a ticket were being represented by an attorney or a legal firm. Most of those were done by pleaing to a lesser offense which lowers the cost and points. I've not seen anyone present any data like this nor attempt to but my gut feeling is the commissioner would most likely not pay attention to the data presented and only the data the citing officer presents. Traffic court in Cali is a joke and a simple form of taxation period.
Off my soapbox now and sorry to the OP for the off topic rant.

[Wakka]

The speed is not calculated by a set figure. Its a percent, so the faster you are going the more off your speedo is.

[Naptime]

Originally Posted by Wakka

The speed is not calculated by a set figure. Its a percent, so the faster you are going the more off your speedo is.

This. Also, if you run a larger diameter wheel from stock this effect is greater at lower speeds.

[E90SoFlo]

Originally Posted by Naptime

This. Also, if you run a larger diameter wheel from stock this effect is greater at lower speeds.

That is the first point my attorney pointed out when I had to get off a ticket.

[persian54]

Originally Posted by Wakka

The speed is not calculated by a set figure. Its a percent, so the faster you are going the more off your speedo is.

Right I know that

But if you're going 150, and want to argue that it was actually 135... not going to really help you lol

[Maestro]

There is a well publicized CA case where someone attempt to use their GPS data to prove they were not going the speed the officer claim. The end result was the person lost, not because he was in fact speeding, he lost because they got all tied down on what was more accurate the radar or the GPS unit. This case was appealed a number of time by the person and the state since the state did not want to loose. They brought in expert witnesses and all. So unless you are prepare for a very serious fight, no court will allow you to use your GSP as proof of your speed.

What I find interesting in these cases is that car now have black boxes and the courts are more than happen to use the data in those black boxes to convict you of wrong doing but you can not use these evidence to prove you were not speeding.

Remember speeding tickets are about money, and any attempt to shut down the money machine will come with a huge fight from the state side.

Just be glad that CA has their speed trap law.

FYI, the GPS tracking data in the above case actually showed the car was in fact going below the speed limit at the time.

[persian54]

Originally Posted by Maestro

Just be glad that CA has their speed trap law.

http://dmv.ca.gov/pubs/vctop/d17/vc40802.htm

Did some reading but couldn't find a definition in layman's terms...

[len56]

Originally Posted by E90SoFlo

From what I have been told its 7MPH and the speedo is set 5 over from BMW.

Get an attorney, they will get you off pretty easy.

why does BMW set your speedo to be wrong??

[NYCGP]

Originally Posted by len56

why does BMW set your speedo to be wrong??

because racecar

[MisterSkiMask]

Originally Posted by len56

why does BMW set your speedo to be wrong??

so they can't be blamed for your ticket

[yakev724]

When I was in court and heard a bunch of tickets ordered, cop just stated he was certified to judge speed at X class during X month/year amd certification granted him /- 5 mph. No radar, speedo, etc. Any notions of cop's judgement being off due to dark/black car/ etc. were immediately dismissed, even when brought up by attorneys.

Judge always took centencing -5mph and issued appropriate fine within a few minutes of beginning hearing. 4-5 cases for this one cop went by just like this (exit 40-42 LIE state trooper if curious)

I was lucky and was there for stop sign which I got dismissed

[yakev724]

And yes, our cars' speedos are adjusted up. You can have it coded to show true speed, also a digital speedo as on the M3.

[len56]

Originally Posted by NYCGP

because racecar

damn, i thought so.

[Wakka]

Originally Posted by len56

why does BMW set your speedo to be wrong??

pretty sure its a legal issue. Every car maker does i think.

[KGB7]

You can have your speedo checked for accuracy and you will be given a certificate that you can use in court that will say that your speedo was showing higher MPH then what you were actually traveling at. This has been used in traffic courts for decades and helped many people either drop the charges or reduce the fines.

[Freakazoid]

Originally Posted by Wakka

pretty sure its a legal issue. Every car maker does i think.

Not all do, it varies a lot on a car by car and brand by brand basis.
It's legal on a certain level, but it's more to cover their asses as it was hinted above. They make sure that there's no way your speedometer is saying a speed slower than what you're actually going (thus opening up litigation)

[Maestro]

Originally Posted by persian54

http://dmv.ca.gov/pubs/vctop/d17/vc40802.htm

Did some reading but couldn't find a definition in layman's terms...

Here is the simple layman's interpretation of the law. In CA they can not write speeding tickets on roads which do not have an engineering study which substantiated the posted speed limits. Not all roads in CA have the required engineering studies and if they do they are too old or they set the speed limit below the 85 percentile which is not allowed.