How far off is your speedometer?

[Brownie Mobile]

ok? buy me one anyways... I use a 2004 f150 for my towing and daily driver sometimes.

Maybe he should get ME one because at some point i'm sure ill have an obdII vehicle.

 

[bobbywalter]

there can be high variance in gps, my phone, my buddies hi dollar fishing gps and his smart phone and the gps speedo in his boat had up to 10 mph variance at cruise speed. my old school phone was the worst...the way i understand it it has something to do with update rates of some sort. his smart phone was the steadiest.



but the gen 1 speedos in theory will have a percentage variance....mechanically speaking it is true, but the rotor/mag system as it ages is anything but reliable.....my variance is very erratic.


sometimes at 90 mph it reads 80....sometimes its on the peg.


things from temperature to just worn out cable make for tough to nail accuracy. getting within 5 mph is tough...but the odo stays on so its not all bad.

 

[superdave1984]

Don't trust the GPS units either. I have an Intellitronix digital speedometer in my Jeep and their GPS sending unit. Supposed to be accurate regardless of tire size, gear ratio, etc. Problems is, if it loses the GPS signal you get an erroneous reading because when it finds the signal again, it reads you have traveled X distance during 0 time. It doesn't recognize the fact it was off for a few seconds. And you get stuff like this while making a turn into your driveway.

Your best bet is a mechanical sender with a gauge that can be calibrated. Find a straight, level stretch of road and measure a mile. Then you calibrate the unit.

 

[Thed]

ok? buy me one anyways... I use a 2004 f150 for my towing and daily driver sometimes.

Offer was only valid for 9/17/2012. Damn man your luck stinks.

 

[straycat]

I check my speedo every once in awhile with those digital sings I see on the highways and around town from time to time. So far I see 45 as 45 mpg, 33 as 33 mpg, 65 as 66 mph and 70 shows up as 69. Very strange but I say it is ok so I don't really worry about it.

 

[shane96ranger]

I check my speedo every once in awhile with those digital sings I see on the highways and around town from time to time. So far I see 45 as 45 mpg, 33 as 33 mpg, 65 as 66 mph and 70 shows up as 69. Very strange but I say it is ok so I don't really worry about it.

I have two of those around the corner from me. They aren't very reliable. They read 24 and 27 when my Escape is at 25.

Sent from a Commodore 64 using a 300 baud modem

 

[bobbywalter]

I check my speedo every once in awhile with those digital sings I see on the highways and around town from time to time. So far I see 45 as 45 mpg, 33 as 33 mpg, 65 as 66 mph and 70 shows up as 69. Very strange but I say it is ok so I don't really worry about it.

thats as good as it gets my psd van works good too...and my minivan.


the rangers is just old as fawk and worn out. its been flipped 4 times. i have worn 3 others to failure. i had it on the dyno many times over the years and spent lots of money on calibrations of various types...