29-06-2016, 08:50 PM | #1 |
S2 - Picking it up
Join Date: Feb 2013
Location: London
Posts: 67
Casino cash: $13034 |
Speedo / GPS
Did a very unscientific test at the weekend comparing speed as shown on speedo to GPS on phone. GPS showed 70mph when car indicated 75mph. How do I know which is right!?
Has anyone else compared theirs!? Cheers |
29-06-2016, 09:14 PM | #2 |
S5, Sport Off, DSC M-track
Join Date: May 2012
Location: london
Posts: 563
Casino cash: $8371 |
It will run about 10% out mate,
My speed limiter comes in at 180mph on the speedo but showing 155mph on GPS
__________________
1979 E24 635csi , 730d work horse , Porsche GT4 |
29-06-2016, 11:46 PM | #3 | |
CSL Register Uber-poster!
Join Date: Sep 2009
Location: Cambridge
Posts: 6,460
Casino cash: $27763 |
Quote:
On an AUTOBAHN my Cecil showed a GPS reading of 174 MPH while the needle was off the clock way past the 180 MPH mark.
__________________
UK CSL No.020 ... after 7 years of ownership I've now SOLD it !!! |
|
30-06-2016, 12:09 AM | #4 |
S5, Sport Off, DSC M-track
Join Date: Nov 2009
Location: Reading
Posts: 731
Casino cash: $19587 |
I think the M3 speedo is calibrated for the standard 18" wheel setup with 225/45/18 and 255/40/18. Mine was quite accurate when it had 18" winter tyres fitted, but is a long way under with the 19s on.
__________________
Now with added SG CSL. |
30-06-2016, 09:51 AM | #5 |
S4 - Getting the hang of it
Join Date: Feb 2013
Location: Bucks
Posts: 143
Casino cash: $9222 |
Trust the GPS not the speedo!
|
30-06-2016, 10:27 PM | #6 |
CSL Register Uber-poster!
Join Date: Nov 2009
Location: Cornwall
Posts: 7,057
Casino cash: $35793 |
|
02-07-2016, 08:44 PM | #7 |
S2 - Picking it up
Join Date: Feb 2013
Location: London
Posts: 67
Casino cash: $13034 |
Maybe BMW looking out for my licence then... Got surprised by a mobile speed gun on the A13 recently and worried didn't slow down in time but probably not an issue!
|
02-07-2016, 09:05 PM | #8 |
S5, Sport Off, DSC M-track
Join Date: Jan 2011
Location: South East
Posts: 580
Casino cash: $12226 |
GPS always reliable
|
04-07-2016, 09:45 AM | #9 |
S6, Sport On, Traction Off
Join Date: Dec 2010
Location: Norwich
Posts: 1,585
Casino cash: $17591 |
That's a long way out - mine is on the speed limiter at an indicated 168mph and that equates to a GPS 161mph. Standard CSL 19" wheels and correct rolling radius tyres.
__________________
Mike R Sarcasm is just a free service I provide. Nordschleife, there's only two barriers to worry about - the ones on the left and the ones on the right . CSL number 044 |
Thread Tools | |
Display Modes | |
|
|