On some of cars where the speedomter isn't working, or if a rear axle ratio change has made your indication off, here is a suggestion.  I think I have 3 or 4 generations of GPS units.  The oldest on has a bad battery and is out of date.  The cost for a new battery and updating are more than a new unit.  I use my oldest one for a speedometer, which is a good temporary solution.  It works off of the vehicle 12 V, even though it's battery is dead.

Paul J. - '57 E Code

Good one. My GPS became my speedometer a couple weeks ago when the "real" one stopped working on a trip home. Buys me time to dig in and figure out what is happening, then figure out how to address it.



I've had a notion to lay out a new instrument cluster with a GPS display in it that will provide MPH readings. Then throw in a bunch of other smaller gauges. Probably a bunch of mechanical gauges. Going all digital seems just too expensive. But it will be hard to part with the cool factor of the wide sweep of the original speedo.

Jim - Erie Colorado, 1957 Country Sedan

I never thought of that one. Great way to check the accuracy of any speedometer. Noiced on recent vacation that according to my GPS, the speedometer in our Mini Cooper S reads faster than the GPS shows. Probably why I haven't got a ticket with it yet.

When I first got the Bird the speedo didn't work and the Nuvi worked great, especially since the roof is fiberglass. Noted rpm's at key speeds, then just drove by the tach at highway speeds.

A side note, a couple go years ago, my wife and I took a train trip across country, it worked when mounted on the window and it was fun to see where we were and how fast the train was going.



Don Wigle

I have a mate (yes it's true) and he calls his GPS Alice. Alice is his wife's name being that Alice is always right, they share the name.

Cheers

Warren

Grizzly (Aussie Mainline)

I have been using GPS's for a while now as a speedo, but now with the new smart phones with GPS built in they are definitely the answer. Here in Oz we have a great app for the iPhone that as well as being a turn by turn navigator also has a very accurate speedo function. Only cost $15 by memory. The advantage of this is that you always have your phone with you and it sits on the dash while driving. In my mainline, it sits on the open ashtray and even gives me warnings when I exceed the speed limit.

I am so sick of buying tickets for the Policeman's Ball and never getting the invitation.

Regards


Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

The battery in the old Nuvi that I use in the T-Bird won't take a charge anymore, so I built a transformer/inverter box that I can now plug into the 6V/Pos Grd. cigar lighter (and also charge my cell phone). GPS a good way to keep track of your speedo accuracy, and double check the calculations used to calibrate it originally.

6 VOLTS/POS. GRD. NW INDIANA

I took my GPS on a flight to Charlotte NC.  Max speed topped out at 542 mph.  It's a definate conversation piece.  I also use my old GPS as the speedometer in my 57.  I haven't figured out the why, but it's dead on at 25 mph but when I doing 65 by the GPS, the speedo registers 80.

Bill Poland

312 V8 - in a 1957 T-Bird

Baltimore, Maryland

Old technology. I had mine rebuilt/calibrated, then double checked & adjusted using a drill & tach. If it's right on at highway speed, then it reads slow around town. Something to do with the magnetic dial action, I assume.

6 VOLTS/POS. GRD. NW INDIANA

My speedometer is (presently) not working either. The new top of the line Garmin that I have has been a godsend for telling me my speed and it has an added feature that it also shows the posted speed limit. I have found that pretty valuable as well. The newest top of the line Garmin is the size of a thin cellphone and also has voice commands, bluetooth, and lifetime free map upgrades.

My only gripe with it is that audio output is rather tinny.

pops (AKA) Clay

'56 Thunderbird