Home | Register | FAQ | Members List | Calendar | Today's Posts | Search |
Social Groups |
Registered
Members: 13,616 | Total Threads: 40,056 | Total Posts: 470,826 Currently Active Users: 828 (20 members and 808 guests) Welcome to our newest member, azihoduhewk |
|
|
Thread Tools | Display Modes |
19-01-20, 05:57 PM | #1 | |
Senior Member
Classic Audi Club Member
Join Date: Apr 2008
Posts: 1,326
|
C3 Speedo - opinions please
Folks,
The speed showing on my sat nav matches exactly the speedo reading on my daily driver (E46), but the speedo on my beloved C3 always shows I am doing exactly 5 mph more than that same sat nav is telling me. Assuming the sat nav and my C3 speedo are not faulty, could that exact 5mph difference be down to the speedo being set up for 15 inch wheels? The car has 14 inch wheels and always has as far a I know, or am I being thick here? |
|
19-01-20, 06:46 PM | #2 |
Senior Member
Classic Audi Club Member
Join Date: Apr 2018
Location: Wales
Posts: 1,157
|
Most older speedo's do over read by about 5-10%. This is a built in safety by manufactures who don't want to get sued if you get a speeding ticket when your speedo is showing 30 at a true 35.
I just found some nice Golf wheels for my boy's polo. They are 14" instead of the standard 13" that were fitted. We did some checks after fitting (using the sat nav) and now the speedo is 100% accurate. It previously over read by about 5 mph. Newer speedos are more accurate. |
20-01-20, 09:21 AM | #3 |
Senior Member
Classic Audi Club Member
Join Date: Feb 2019
Location: Near an MB ur Quattro
Posts: 1,171
|
If the incorrect reading was down to different wheel sizes, it would be a percentage difference (so it would always be, say, 7% out) rather than a constant MPH difference.
Maybe the needle has been replaced, and put at a different position? |
20-01-20, 10:14 PM | #4 | |
Grown up member
Classic Audi Club Member
Join Date: Sep 2011
Location: Back in the Emerald Isle
Posts: 772
|
Quote:
|
|
21-01-20, 08:20 AM | #5 |
Senior Member
Classic Audi Club Member
Join Date: Apr 2018
Location: Wales
Posts: 1,157
|
I used this site for my boys Polo. It tells you the % change for the wheels size.
https://www.wheel-size.com |
21-01-20, 04:09 PM | #6 |
Senior Member
Classic Audi Club Member
Join Date: Apr 2008
Posts: 1,326
|
Thanks Chaps.....
|
22-01-20, 11:25 AM | #7 |
4 ring whore!
Classic Audi Club Member
Join Date: Dec 2007
Location: Wirral
Posts: 3,910
|
Thanks to the fact magnets deteriorate with age my Cq now under reads by 4mph at 70mph (satnav says 74mph) My A5 is spot on accurate as I discovered now, until recently assumed it was under reading as cars used to do so always set my cruise control at 32mph in a 30
__________________
Coupe quattro 1986:-~450bhp + loooong list of mods! Audi A7 Bi-TDI SLine Black edition 2015 mapped to produce 600lb/ft torque! Audi S4 4.2 V8 cabriolet 2004:- |
Bookmarks |
|
|