Correct speed?

In general I tend to consider the GPSr to be correct, since it recalculates the speed constantly by integrating time and distance over and over again. I figure the car manufacturers are being a little conservative by making you 'think' you're going 70, while actually doing 67, so you'll drive a little slower.

If I am driving through an area known for speed traps I'll use the faster speedometer value any day to avoid a ticket.

So, if you are pulled over for going over the speed limit, you should be able to show the Police your Data screen and show your Max speed. Of course you have to be sure that you did not exceed the speed limit.

We have 3 fairly new vehicles in our driveway (some are company cars) and I tried my new GPS unit in each one just to observe the speed readings. Results:

Ford 500 - dead on with GPS
Jeep Compass - Jeep reads about 1 mph slower than GPS, very close
Toyota Tacoma - Toyota reads about 3-4 mph faster than GPS, now I know why everybody is always flying by me when I drive the truck.

My jeep wrangler reads 3-4 miles faster than I am actually going. Had it checked with Sheriff radar.

I use my nuvi on a touring motorcycle and it shows about a 10% difference in mph. I know this to be correct because most mc manufacturers have optimistic speedos.

This subject has been discussed at great length (or ad nauseum) in thread:

http://www.poi-factory.com/node/6695

So has update to 2009 maps for free but we still get more.

I would go with which ever one reads the fastest, that way I'm either going the correct speed or slower. If you go by the slower reading you'll either be going that speed or faster.

I think you knew that already, but just wanted to say something smart.

Oh, and the Max Speed screen wouldn't work since it shows 542 mph.

You understand that this would not fly, right?
BTW this has been discussed already in more than one threads.

What is the difference from this one than ,price of gas, mount won't stick,how to load poi's how to load mp3's 2009 map updates, how to load icon, and on and on . People don't read FAQ, and any group or board before they post. We are all quilty. just us the skip or return to privous page button. Works every time.

play nice

I would never use the GPS to verify my odometer readings. For one thing I don't use it for trips to the grocery store, etc., so it's alwasys going to do less traveling than my car. And when it's getting itself connected to the satellites, the vehicle can start out a few blocks off, then moves to the correct location, and that would seem to me to skew the data that it records.

I rarely even look at the Max Speed and other data on that screen. Only when I'm on a long drive and I want to see how I'm doing for average speed... that is a more interesting and useful bit of information for me, and it's one that the instruments in my car don't calculate.

Ohhhh, I'd be careful with that! I have not seen it yet on my Nuvi, but I can tell you I have seen "anomolies" for top speed on my eTrex. I think the "fastest" I have ridden my bicycle on a training run was around 900mph ... It was fun showing my friends.

My CTS speedo is spot-on, as was my old PT Cruiser. But I recently rented a PT and it was conservative by 2-3 MPH. It annoyed me to no end.

You can do the old "flying mile" test. Set your cruise control to 60mph, drive a mile, time it. It should be 60 seconds (or 30 for 1/2 mile, etc).

Of course, if you do this during rush hour on the GSP, you will probably get run off the road.

I would check my max speed in the GPS frequently so I can guage how accurate it is over time and if something glitches it and a false report is shown, I can start a log of this. Maybee something is effecting the GPS?

Virgo