SPEEDOMETER ACCURACY

[QQBIRD]

IN MY NEIGHBORHOOD I PASS A POLICE RADAR CAR SETUP WITH A LARGE DIGITAL READOUT OF A PASSING CAR'S SPEED SO AS TO INDUCE ALL TO SLOW DOWN AND OBSERVE THE SPEED LIMIT (30MPH)
MY SPEEDO READS 30 BUT THE POLICE READOUT READS 26. MY DURANGO READS 30; SAME AS THE POLICE.
ANY ONE ELSE HAVE A SIMILAR EXPERIENCE?

 

[tbird]

Originally posted by QQBIRD:
IN MY NEIGHBORHOOD I PASS A POLICE RADAR CAR SETUP WITH A LARGE DIGITAL READOUT OF A PASSING CAR'S SPEED SO AS TO INDUCE ALL TO SLOW DOWN AND OBSERVE THE SPEED LIMIT (30MPH)
MY SPEEDO READS 30 BUT THE POLICE READOUT READS 26. MY DURANGO READS 30; SAME AS THE POLICE.
ANY ONE ELSE HAVE A SIMILAR EXPERIENCE?

I guess you just learned why you can go 5 MPH over the speed limit without getting pulled over. I've observed the same thing on those, they are about 5MPH off.

When I had my Mustang, I loved to drop it down into 2nd and get on it to see how fast I could make the numbers go up on it.

TBird

 

[rt2esq]

I went by one those today. The sign said "80", I was too busy looking for cops and hitting the brakes.

I think the wedge design might be tweaking the radar!!!

RT2ESQ
Triple Black #1049

 

[RACERROGER]

Funny how most people slow down when they see one of these units. Why? 9 times out of 10 there is no police around. Granted one should always observe the speed limit BUT..........

It reminds me of how Americans will automatically go to the back of a line before asking if it is the right place to be. i.e. Movies, Take out restaurants, etc.

 

[Tip]

I've been under the impression that those boxes have cameras in them. Seriously! Maybe they just tell us that to slow us down, but I'm not taking the chance! I guess I'm a chicken!

------------------
Blue/Blue Premium '02 (Waiting sort of patiently)
Yellow '76

 

[DavidA]

There is no camera in them. They are used quite effectively to slow traffic and, secondarily as a PR move to assist people with speedometer accuracy. Personally, I've found them to be quite inaccurate in themselves, usually by as much as 5 mph as indicated by my various vehicles.

 

[thenewtbird2]

We've checked our speedometers for accuracy by using timed, measured miles on freeway checkmile setups along interstates, then checked them with those large digital readouts and find the readouts to be quite accurate.

We only have 1 car that reads accurate and it's speedometer is NOT set up as it was originally setup by the manufacturer.
Our 89 Chryslers all read faster than we're actually going. All Fords we've driven in the past have not had accurate speedometers - some out of whack by as much as 10%.

Don't know of any makes that are accurate and it shows on the freeway when people spot a cop on the road.

(I'm saying that to bring out those of you that KNOW your car's speedometer is accurate. QQbird - I'd say that your Durango is accurate)