Speedometer accuracy

[Marco8]

I have owned my 911 for about 6 months and I have wondered about the accuracy of the speedometer (overstating the actual speed). Well I finally took out my GPS to check and I came up with the following conclusions:

1) The speedometer is fairly accurate, difference (overstatement) is 1 - 1.5mph up to 85 (I didn't check for speeds above that).

2) 911s are fast......they are wonderful handling machines and are meant to be driven fast.

3) People in AZ drive fast, consistently about 10 - 15mph over the posted speed limit. Thats why I thought my speedometer was inaccurate, here I was cruising at 80 and being passed, or driving at 80 and keeping up w/ traffic, man, I thought my speedometer has got to be off....not.

[Early_S_Man]

Marco,

If you want your speedo to be dead on ... you may want to try the external trimpot suggested in this thread:

smokey speedo

[morganb]

Mine reads about 7% fast at about 60 MPH or 100 KMH. All stock.

[RoninLB]

Originally posted by Marco8
3) People in AZ drive fast, consistently about 10 - 15mph over the posted speed limit. Thats why I thought my speedometer was inaccurate, here I was cruising at 80 and being passed, or driving at 80 and keeping up w/ traffic, man, I thought my speedometer has got to be off....not.

Phoenix I-10 HP want to tag those traveling at 89+mph

[AngM018]

I live in NASCAR country, 10-15 over is slow in these parts. The only problem is the speeders have no idea how to drive so I stay clear. It also doesn't help that my speedo is KPH only so I'm constantly converting in my head.... It helps the brain muscles, especially when the state trooper is right behind me, and the adrenaline is pumping!

[nolove670]

i agree...i live in los angeles and at nite on the freeway i cruse at 80+ and get passed up all the time. and i have a get out of jail free card