Best PC GPS Program

[vskid]

The speedometer (and I assume the odometer) in my truck is off. I want to be able to track my gas mileage, and an accurate distance is required to compare my mileage to others. I have a Holux M1000 bluetooth GPS receiver and a couple old laptops (PII, 64mb ram; PIII, 256mb ram) I could use, but I'm not sure what program to use. I don't really need maps, just a speedometer/odometer. Microsoft Streets and Trips is nice, but I'm not sure if it can track the distance traveled over several sessions. Anyone know of any free/cheap solutions?

[bicostp]

Who gives a damn about fuel economy with a truck? [/redneck]

Why not just get the speedometer calibrated? How 'off' is it?

[vskid]

I care because I'm the one paying for gas. This tank is my benchmark to see what it would get with average Joe driving it (fairly fast accelerating, etc). Then I'll base my goals on that (I'm hoping 25-30mpg highway, but that'll need some aerodynamics mods and such).
I'm not sure why the speedometer is off. I'm pretty sure everything is more or less stock. At ~25mph its 2-3mph off, goes up to 5 off at 35mph. The first day I drove it I thought everyone else was going fast because I had to go 5-10 over to keep up. I plan on getting different tires soon, and I might get 2 sets (onroad and offroad), so any calibration would probably be a waste.
So, a GPS is pretty much my best option, and using hardware I already have makes it even better.

[eagle5953]

I'm not sure why the speedometer is off. I'm pretty sure everything is more or less stock. At ~25mph its 2-3mph off, goes up to 5 off at 35mph.

So the error correlates directly with speed... at about 15% higher than true.

Perhaps the wheels are the wrong size. If they were too small, it would take more revolutions of the tire to go the same distance - thus, the speedometer would register a faster speed than what you were actually going.

[MasterPrime]

This One

not sure if it's just for phones or not.