Speed Not Calibrated

[utopia]

Guys noticed on those "current speed" signs you're always a little slower then what the speedometer says?

[Rotus8]

Guys noticed on those "current speed" signs you're always a little slower then what the speedometer says?
My speedo is dead on, calibrated with GPS. This is surprising, every other car and motorcycle I have owned has the speedo reading high by about 5% stock.

[Nutari]

Guys noticed on those "current speed" signs you're always a little slower then what the speedometer says?
those things are never accurate.

[utopia]

the speedometer or the sign? i hope the speedometer is fast so when i throw rims on my car it should be just about accurate then

[clicknext]

Yeah, I've noticed that too. I'm curious about the accuracy of those, and how it actually measures speed.

[DeepBlue]

Mine is dead nuts, checked it with my GPS.

[SeanMSIII]

Mine is dead nuts, checked it with my GPS.

This is bad news. I've been counting on mine to be fast and keep me just under 10 mph over when I want to be.(five-0)

[Rotus8]

This is bad news. I've been counting on mine to be fast and keep me just under 10 mph over when I want to be.(five-0)
It will start reading fast as your tires wear down. (naughty)

[$inCitySpeed3]

never noticed

[chuyler1]

Keep in mind, when your speedo is off, so is your odometer and any gas mileage computed from your trip meter.

[clos561]

works fine...(stash)

[matsuda]

Mine is also very accurate.
Gone are the days of cable speedos.

[matsuda]

Keep in mind, when your speedo is off, so is your odometer and any gas mileage computed from your trip meter.
That is not necessarily true.
A mechanical speedometer (like other mechanical devices) has tolerances.
It's possible for the odometer to be accurate even if the speedometer is not.

It would be a big no-no (for obvious reasons) if a speedo read low.

[clos561]

mine works fine..cops have been behind me and i do the speed limit then they pass me and look for other victims

[chuyler1]

Cops usually only pull people over for 10+ over the limit. Inaccurate speedos and radar guns are part of the reason...they want someone who is definitely guilty.

[B1GHAM]

all of the "current speed" signs in my area run off of older X band radar technology (what brand/make I couldnt tell you).

keep in mind radar guns have to be calibrated for accuracy, so theres a higher possibility that the SIGN is wrong and not your car.

IIRC the MS3 uses a mechanical speedo gear, which would be really hard to be set innacurately (assuming stock tire hieght...)

chuyler is right though - most cops arent going to pull for more than 10+ mph. Its a waste of time as it could be anything from your car being off to their radar gun being off... unless they are extremely bored/have a clear reading on you. in my state up to 9mph over, its a slap on the wrist.

more than 10mph over the speed limit and its clear to both the officer and yourself that you are speeding. you may not realize a few miles over, etc.