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The 2.0 718 runs 24.7 mph per 1000 rpm in 6th gear (both 6S manual and 7S pdk). The rev counter reads each pulse from the coils so is reliable. Just check your speedo reading at 1000 rpm in 6th gear. If it’s more than 25 mph, call the conspiracy police…
FWIW, here's the gear ratio's for manual and pdk 2.0t and 2.5t (not 4.0's).
The 2.0 718 runs 24.7 mph per 1000 rpm in 6th gear (both 6S manual and 7S pdk). The rev counter reads each pulse from the coils so is reliable. Just check your speedo reading at 1000 rpm in 6th gear. If it’s more than 25 mph, call the conspiracy police…
Perhaps the constant need to recalculate actual speed in your head is meant to stave off dementia
Saw this thread the other day and decided to pay attention to speedo accuracy on my car.
My Uniden R3 has a gps speed display and it is dead nuts the same as my dash indicated speed. My car is an 18CGTS on stock sized tires. If my speedo is fast then the GPS in the uniden is miscalibrated as well.
@reacp911 My BGTS speedo also reads high. There does appear to be a calibration menu in PIWIS 3. I haven't adjusted mine yet due to winter conditions but plan to do so in the near future. Our Alltrack is also very accurate but our Audi Allroad not so much.
** Edit ; The last three lines translate to velocity calibration characteristics.
In addition to the above velocity calibration characteristics chart in PIWIS, which are different for GTS (above) vs GT4 (below), I discovered that PIWIS has three different Speedometer Country characteristics settings; UK, USA & RDW. The USA calibration is 1 to 1 (x axis = y axis) the RDW and UK are not 1 to 1, ( x4 = 99 but y4 = 102 and x5 = 153 and y5 = 156 etc).
In addition to differing gear ratios , manual vs PDK and variations in tire OD this may help to explain why some have accurate speedos while others do not. I haven't tried to adjust any settings yet as my GTS is still in storage but will look into this in the future.
^^^ its similar to the coolant temperature calibration. With GT4s and Spyders x = y but GTS 4 (and probably all non GT's temps from x = 80.3c to x = 110.3c are displayed as y = 90c. This why our coolant temp always reads 90c while the actual temp is up to 15c warner (in Normal mode)
Oh, been meaning to look into the proper software for Porsche diagnostics. I have ISTA+ and VAGCOM running on a windows 7 virtual machine on mac air. Both work fine. I could not get VAGCOM working on Windows 11 on my new MacBook although others have reported it works on M1 chip Macs...>I have to figure that out. Anyway, do you know if PIWIS supports VM's on macs??? Mike
PIWIS 3 / Win 10 VM won't run on M1 Macs but will work on older Intel Macs. AFAIK PWIS 3 / Win 11 VM should be able to run on M1 Macs but still has issues.
I've been meaning to test this by changing the wheel size (Clubsport custom sizing per wheel) and comparing speedo to GPS. I should be able to do this on the weekend
03-14-2023, 08:51 PM
