|
||
|
21st December 2014, 18:52 | #1 |
Regular poster
rover 75 tourer Join Date: Oct 2014
Location: crediton
Posts: 59
Thanks: 21
Thanked 7 Times in 6 Posts
|
Speedy Speedo
Was driving home last night along a Devonshire B road and noticed the speedo was indicating something over 70mph. No way I thought, so today I had a little drive with my Garmin sat nav in the car which indicated that the speedo was fast by 6/7 mph at a genuine 60mph. That's 10% plus error. Is this normal? anyone else noticed this on their own cars?. My car is on it's original wheels with correct size tyres.
|
21st December 2014, 19:00 | #2 |
Banned
MG ZT V6 190+ Join Date: Sep 2008
Location: Leeds
Posts: 33,223
Thanks: 41
Thanked 1,614 Times in 1,416 Posts
|
Most manufacturers over read their speedo readouts. It's nothing unusual.
|
21st December 2014, 19:08 | #3 |
Regular poster
rover 75 tourer Join Date: Oct 2014
Location: crediton
Posts: 59
Thanks: 21
Thanked 7 Times in 6 Posts
|
I agree they certainly used to but I thought more modern stuff was reasonably accurate. This sat nav has been used in my Mercedes van and my sons Toyota, both these vehicles are accurate to 1 or 2mph.
|
21st December 2014, 19:23 | #4 |
Doesn't do things by halves
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,381
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
|
Michael,
There's a lengthy thread somewhere on this subject with many diverse views including just whether sat. nav. readings are themselves reliable. If you have a message centre in your instrument pack, a digital speed display can be activated by T4. This will give you the more "accurate" speed you desire. Since the same signal drives both this digital display and the analogue dial, its likely that the error was deliberate as pab suggests. Simon
__________________
"Whatever is rightly done, however humble, is noble." Sir Henry Royce. |
21st December 2014, 21:23 | #5 | |
Passed Away
Rover 75 Connie Tourer Join Date: Dec 2013
Location: Guildford
Posts: 2,582
Thanks: 682
Thanked 979 Times in 612 Posts
|
Quote:
Lot's of threads on here about it, I now rely on my Sat/Nav for a true reading, after all if it accurately shows when I pass a side road, it must be very accurate at showing my speed. Lot's of threads on here about it but most of us find, to get an accurate speed reading, let the needle point 5 mph above the speedo marking. |
|
21st December 2014, 21:31 | #6 | |
Regular poster
rover 75 tourer Join Date: Oct 2014
Location: crediton
Posts: 59
Thanks: 21
Thanked 7 Times in 6 Posts
|
Quote:
|
|
21st December 2014, 21:36 | #7 | |
This is my second home
none but not gone Join Date: Mar 2013
Location: March, Cambs
Posts: 16,437
Thanks: 894
Thanked 4,247 Times in 3,025 Posts
|
Quote:
the digi speedo on the ipk is more accurate but depends on tyre size and pressure..
__________________
[SIGPIC][/SIGPIC]….All praise Bananaswan…. |
|
21st December 2014, 22:27 | #8 |
Avid contributor
MG ZT-T Join Date: May 2014
Location: Romford
Posts: 203
Thanks: 35
Thanked 33 Times in 28 Posts
|
As tyres wear out they could be anything up to 30mm smaller on the circumference over new tyres. So maybe manufactures build this in. Not sure though
|
21st December 2014, 23:18 | #9 |
This is my second home
Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008
Location: Birmingham
Posts: 11,394
Thanks: 6,587
Thanked 2,262 Times in 1,729 Posts
|
BBeen through 50 mph areas on the m/way at 55mph and never had a flash on the cameras
__________________
Great Barr, Birmingham. |
21st December 2014, 23:40 | #10 | |
Passed Away
Rover 75 Connie Tourer Join Date: Dec 2013
Location: Guildford
Posts: 2,582
Thanks: 682
Thanked 979 Times in 612 Posts
|
Quote:
I think I'm right here but if you can pin point just how far out your speedo is, Klarzy can make you a re-calibrated speedo facia. If I'm wrong I'm sure Klarzy will correct me. |
|
|
|