Thread: GPS speed readout

I drive off the GPS speedo most of the time. That being said the speedo in my Disco2 is bang on the money.

My VW speedo is out by 7% I took it in to get fixed under waranty and the dealer told me this reading 7% high was an intentional designed in feature and they won't fix it?? OK but when my car has doen 100,000KM it'll read 107,000KM on the odometer

Cheers

Michael

Originally Posted by Disco Mick

I drive off the GPS speedo most of the time. That being said the speedo in my Disco2 is bang on the money.

My VW speedo is out by 7% I took it in to get fixed under waranty and the dealer told me this reading 7% high was an intentional designed in feature and they won't fix it?? OK but when my car has doen 100,000KM it'll read 107,000KM on the odometer

Cheers

Michael

Strangely enough, I'm not sure this actually equates - we have a Subaru that over-reads by about 8% but the odometer is always bang on with the (NSW) blue odometer check signs, and every 5km on many roads it has the distance to the next major town and I'm led to believe they are spot on, it correlates with those perfectly too! Whereas my S1 Disco used to over-read by 4% which now has larger tyres and is almost spot on for speed vs GPS, but now 4% under with odometer... if that all makes sense!

I drive with tomtom on pda on most of the time and found that with my current tyres (265/75/16 muds) my speedo is within 1-2 % of the gps reading. Tomtom also shows your speed in relation to the gazetted speed limit and flashes red and sounds a bell if you go over that limit.

Originally Posted by seano87

Strangely enough, I'm not sure this actually equates - we have a Subaru that over-reads by about 8% but the odometer is always bang on with the (NSW) blue odometer check signs, and every 5km on many roads it has the distance to the next major town and I'm led to believe they are spot on, it correlates with those perfectly too!

Interesting, I'll have to check that and see if mine does the same.

Cheers

Michael

When on the open road I always use my GPS to check speed against my speedo reading (D1) generally speedo reads + 8 - 10% at speeds over 100 Klms. I don't worry around town as the + 5 % at urban speed limits I just use as a fudge factor to reduce my chances of a speeding fine.

I have done some basic time and space calc's and I recon my GPS is 99.99% accurate if I can maintain a constant speed for a few seconds between readings.

As for the GPS being "shut down" by the Pentagon (the Pentagon IS the controlling authority by the way) they have publicly acknowledged (direct communications to various transport authorities such as international shipping and aviation agencies) of any impending actions. I am aware of this happening as far back as the early 90's.

Now I am not a "technophobe" but as I understand it the Pentagon was able to "adjust" the differential which would prevent the bad guys from using the GPS system to "guide" weapons. It can also adjust the degree of accuracy.

The US acknowledges that the world communication and transport systems are now so reliant (US aviation and shipping alone would be enough) on the GPS system that to "SHUT DOWN" the system would cause considerable risk.

Unless the US (or NATO) forces are going to take on a modern technically advanced military there would be little or no chance of any significant reduction in GPS reliability. And if an invasion on a technically advanced military where to occur then various other "E" weapons would most likely be used. The US forces including ground forces are now so reliant on "situational awareness" that there would be a lot of "lost grunts" if the GPS system was switched off.

If we got into a war that horrendous that the GPS system was switched off I would be heading for the most remote place I could find and getting lost would be a tactical advantage and I would not give a dam about my GPS.

Thommo
D1V8ESman
Youth is waisted on the young