Speedo options for my Jeep

[technetium-99m]

I have no love for the speedo unit in my CJ5 right now. The fuel gauge and the turn signals are the only items that work.

So I'm going to replace it while updating the dash a bit. I've found several electronic speedometers that would work for me, and they can be calibrated for tire size and gears. Then I saw Autometer made a GPS unit that works with their electronic speedos. Small antenna that uses GPS to give you a speed instead of getting it from the cable.

Has anyone used something like this? Seems similar units are used on boats and the part seems to have good reviews and be well built. What say the masses?

 

[Burk Cornelius]

From what I know about GPS, they wouldn't be as accurate as one with a cable

 

[Patrick Palmer]

As an added thought, we had a week or so where our Nissan Armada's speedometer was hosed. It was during a trip to see family in Iowa. Rather than bringing it to a local Nissan Dealer we used the TomTom GPS device to give us our speed as it provided it via the UI. Since it works, maybe you want to save yourself $150 and instead of buying a GPS device, use the one in your smartphone - assuming you have an iPhone?

http://itunes.apple.com/us/app/gps-speedo-speedometer-head/id398663522?mt=8

Plus, it'll growl like a mountain lion when you go over your desired speed limit! Honestly though, it'll work in a pinch for only $0.99.

That being said, our TomTom's speed is often 2-5 mph different than the mechanical one we use in the truck. I'd say stick with the non-gps one. GPS is probaby fantastic for boats and aircraft, but boats don't get pulled over for going 6 knots above the Nautical Speed Limit.

Medicius

 

[Spiff]

I used my Garmin Nuvi for a speedometer for a wihle after the one in my truck went out. I'm more inclined to trust a GPS device that calculates it directly than a mechanical device that has about 6 different things influencing its accuracy. GPS has to do some pretty crazily precise operations to figure out where it is.

 

[technetium-99m]

I'm currently using a Garmin GPS for a speedo, I'm just looking for an option that's in the dash and works without having to secure the thing when I leave the vehicle or dig in my pockets to stick the smartphone somewhere I can see it.

Still undecided now, but if I want to use the cable I'm gonna have to replace it and the gear in the transfer case, the GPS option just seems easier. I was hoping someone had experience with either of the two. Pirate 4x4 seems split on the issue if anyone was curious.

 

[Chambers]

Hard to speed in a CJ5!

 

[technetium-99m]

Hard to speed in a CJ5!

It does get a little frightening above 65.

 

[Wall]

to anyone that's ever ridden to a match with him, the thought of GT speeding is just funny anyway.
He don't drive like Rusty, that's FoSho!!!

 

[dennishoddy]

Ok, here is the scoop. I have a gps on my phone, tom tom, and a hand held garmin.
All read 2mph slower than my indicated speed on the dash.

Years ago, in the military I worked on a Microwave communication site in Korea. Out of boredom, we decided to link up all of the military sites using spare channels, untill we had a channel around the world. (this was before satelite communications.) Once we got this done, we sent a signal. It took about 12 seconds to make the trip. We were kind of dumbfounded as it travels at the speed of light. After a lot of beer and thought, we finally figured out that it has to travel through a lot of electronics, that slow it down. Capacitors, resistors, etc.

I'm thinking this is why the gps is different that the mechanical dash speed. Oh yeah, when your tires wear down, the speed will change too. Not much though.

 

[oklaccer]

I see a lot of GPS from the aviation side and here is my .02. The GPS units for cars or other surface vehicles are tuned to provide a local position fairly accurately. If you are using cruise control, the GPS will probably be more accurate, as it is giving you an average over a short period of time, (last 2-3 seconds). Once your speed is set, the GPS will be accurate. Different units will have different sampling rates, but most will sample at least once per second. Where the GPS units have a hard time is in continually changing speed conditions. Because of the sampling rate and average time functions built in, there will always be a lag. When you have a chance to do so safely, from a standing start, accelerate at a rapid rate and see how long it takes your GPS to catch up. Or the opposite, from a steady speed, brake hard and see how long it takes to catch up. You can see the lag. But again, if your speed is steady, the GPS will be accurate.

 

[Rick Means]

For a low speed vehicle like the CJ, a good GPS is better, plus when you are really off the beaten path it will help you retrace routes (often very useful when something falls off your vehicle) and finding ways around obstacles.

 

[Burk Cornelius]

Every time I see this thread moved to the top, I think "GT is going to wear a speedo in his Jeep? " Ewwwh

 

[Ksmirk]

I can't for the life of me recall how large the opening is in the CJ but for the dash in my 56 Chevy PU I got constructive and made a plate that would fit where the gage cluster went then bought all my gages I wanted and layed it out, took it to a buddy with a mill and we cut it out. Dropped in the new gages and AWESOME! I got more comliments on that little project. Just an idea. Later,

Kirk

 

[technetium-99m]

The speedo opening is large enough to fit a small child through. Ill have to make a plate to fit over the whole deal to do much of anything.