Actual speed - Page 5

James.uk · 16th March 2010, 10:51

When my car speed reads 73 my Garmin Satnav reads 70, so 3 mph out on the plus side....

baggie9 · 16th March 2010, 15:35

I got stopped for speeding 46 in a 40 zone in my mgb in the 70s.The squad car that followed me said i was doing 46,my speedo was reading 40 because i was awre i was being followed.They gave me a ticket,my speedo was a new one.So i telephone Smiths who had my clock back and verified it.I went to court and got off with the charge, the police car speedo hadnt been calibrated.

Vaimaca · 4th March 2011, 16:28

Talking about the Police,
I have a Connie 75 and my speedo is also not showing the true speed, so I was being followed by a patrol car in an area of 30mph and following my speedo indication (unaware at that time of the 10% off calibration) I was stopped for driving too "slow"!!

They commented that I was doing 25mph and therefore creating a hazard.

I then asked if it was legal to follow the SatNav instead and surprisingly he agreed!!
I asked if he was sure it was ok as it could have been inaccurate but he confirmed it again!!

I'm still not following my SatNav all the time by I guess it's best to be stopped for driving to slow and not too fast...

Alan.F · 4th March 2011, 21:38

Quote:

Originally Posted by David3807

All above sounds about average for a 75. My speedo reads 10% fast throughout the range ie True 30 indicated 33. True 70 indicated 77.

I do wonder what the speedo was calibrated for and on which tyres although as far as I know the biggest difference in circumference for any of the available wheel/tyre combinations was about 2% which is not nearly enough to get me speedo anywhere near accurate.

Perhaps thats why 75's have got a pipe and slippers image:lol:

This is exactly how my speedo reads

suzublu · 4th March 2011, 21:43

Been out today playing with my new sat-nav,& 30 was 26, 70 was 64.Speedo first,sat-nav second. & for James-uk, 92 degrees!

starbug2 · 4th March 2011, 23:54

via 2 sat navs my speedo is about spot on

but then it has had none standard wheels on so maybe that is why

HarryM1BYT · 5th March 2011, 08:04

Quote:

Originally Posted by crofts

It's amazing how many drivers obviously think the limit on a 2 lane A road is 60mph. !

On a two lane A road unless there is a restriction it is 60. On an otherwise similar dual carriageway it is 70.

Many wrongly think it is 50 and 60 for the above cases.

stocktake · 5th March 2011, 08:09

On my recent speed awareness course

it was pointed out that even if it is a four lane carriage way ( two lanes in each direction ) if there is no definate seperation then the limit is 60mph.

The example he used was that if you can roll a tennis ball from one side of the road to the other with no obstruction then the limit is 60mph.

I have to be honest any say i learnt something there

BigRuss · 5th March 2011, 08:33

There's a coding difference between 18" rims and the rest of the wheel range which alters the speedo calibration allowing for the difference in circumference.

So if your running 18's on a car that's setup for any other tyre size your speedo will be more accurate, for those setup for 18's changing to any lower wheel size will increase the over-read.

Russ

egremont · 5th March 2011, 10:16

You may like to refer to my thread that records the installation of a speed corrector kit. The attachment is seven pages and includes photos and schematic.
The article was lodged in early 2010, and from memory is still held in the Subscribers section.
An earlier post in this thread stated that the speed tolerance in Australia was +10% to -10%. In the State of Victoria (and I believe in others) you will receive a speeding notice for exceeding the limit by as little as two or three kilometres per hour. Convert that to miles per hour and the tolerance permitted by our constabulary is very little. My speedometer had an error rate of 10% but since installing my kit, its reading is spot - as evidenced by passing radar checks without any incidents.

A great feeling of security - as from time to time one reads of motorists caught by police number plate recognition checks with unpaid fines totaling a few thousands of dollars. On the other hand, try motoring on a highway at 10% under the limit - sadly we have road rage.

egremont.

4th March 2011, 16:28	#43
Vaimaca Newbie Rover 75 Join Date: Dec 2009 Location: Morder Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts	Police checks... Talking about the Police, I have a Connie 75 and my speedo is also not showing the true speed, so I was being followed by a patrol car in an area of 30mph and following my speedo indication (unaware at that time of the 10% off calibration) I was stopped for driving too "slow"!! They commented that I was doing 25mph and therefore creating a hazard. I then asked if it was legal to follow the SatNav instead and surprisingly he agreed!! I asked if he was sure it was ok as it could have been inaccurate but he confirmed it again!! I'm still not following my SatNav all the time by I guess it's best to be stopped for driving to slow and not too fast...

4th March 2011, 23:54	#46
starbug2 This is my second home Silver Rover 75 Tourer Club SE CDTI + MGF 1.8 in BRG Join Date: Jun 2009 Location: EARL SHILTON Posts: 5,937 Thanks: 235 Thanked 144 Times in 108 Posts	via 2 sat navs my speedo is about spot on but then it has had none standard wheels on so maybe that is why __________________ Membership No. 7576 now with 2020 MG ZS 1Lt TURBO engine with automatic 6 speed gearbox to help keep the 75 and MG F going as long as possible

5th March 2011, 08:09	#48
stocktake Vis Whiz Rover 75 2.5 auto Saloon Join Date: Jun 2007 Location: LEEDS Posts: 20,591 Thanks: 2,057 Thanked 3,056 Times in 1,621 Posts	On my recent speed awareness course it was pointed out that even if it is a four lane carriage way ( two lanes in each direction ) if there is no definate seperation then the limit is 60mph. The example he used was that if you can roll a tennis ball from one side of the road to the other with no obstruction then the limit is 60mph. I have to be honest any say i learnt something there __________________ Dave... Lost a few stones and a Gall Bladder and part of a bile duct and all of my dignity in the suppository incident

5th March 2011, 08:33	#49
BigRuss Premium Trader 75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4) Join Date: Jul 2007 Location: Liversedge, West Yorkshire Posts: 5,405 Thanks: 1,105 Thanked 1,340 Times in 661 Posts	There's a coding difference between 18" rims and the rest of the wheel range which alters the speedo calibration allowing for the difference in circumference. So if your running 18's on a car that's setup for any other tyre size your speedo will be more accurate, for those setup for 18's changing to any lower wheel size will increase the over-read. Russ __________________ Replacement Key Service http://https://the75andztclub.co.uk/...d.php?t=244732 Full T4 Testbook diagnostics available. Diesel ECU repair and replacement. Options enabled or disabled as required. Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160 MG 160 V6 to 177 upgrades available P.M. for details.

5th March 2011, 10:16	#50
egremont Loves to post Rover 75 Connoisseur SE. Auto. Saloon. SE Join Date: Apr 2009 Location: Melbourne Posts: 458 Thanks: 163 Thanked 198 Times in 70 Posts	Electronic Kit to Correct Speedometer Reading. You may like to refer to my thread that records the installation of a speed corrector kit. The attachment is seven pages and includes photos and schematic. The article was lodged in early 2010, and from memory is still held in the Subscribers section. An earlier post in this thread stated that the speed tolerance in Australia was +10% to -10%. In the State of Victoria (and I believe in others) you will receive a speeding notice for exceeding the limit by as little as two or three kilometres per hour. Convert that to miles per hour and the tolerance permitted by our constabulary is very little. My speedometer had an error rate of 10% but since installing my kit, its reading is spot - as evidenced by passing radar checks without any incidents. A great feeling of security - as from time to time one reads of motorists caught by police number plate recognition checks with unpaid fines totaling a few thousands of dollars. On the other hand, try motoring on a highway at 10% under the limit - sadly we have road rage. egremont.

16th March 2010, 10:51	#41
James.uk Passed Away 2002 Pale Blue. Rover 75 CDTi Connoisseur auto. 170K miles Join Date: Dec 2008 Location: Near the M67. Posts: 14,509 Thanks: 199 Thanked 585 Times in 397 Posts	When my car speed reads 73 my Garmin Satnav reads 70, so 3 mph out on the plus side....

16th March 2010, 15:35	#42
baggie9 Posted a thing or two Jaguar s Type Join Date: Feb 2009 Location: tipton Posts: 1,369 Thanks: 3 Thanked 1 Time in 1 Post	I got stopped for speeding 46 in a 40 zone in my mgb in the 70s.The squad car that followed me said i was doing 46,my speedo was reading 40 because i was awre i was being followed.They gave me a ticket,my speedo was a new one.So i telephone Smiths who had my clock back and verified it.I went to court and got off with the charge, the police car speedo hadnt been calibrated.

4th March 2011, 21:43	#45
suzublu This is my second home rover 75 1.8 vvc club se wedgwood blue Join Date: Aug 2009 Location: Seaton Carew Posts: 26,920 Thanks: 65 Thanked 7,142 Times in 4,642 Posts	Been out today playing with my new sat-nav,& 30 was 26, 70 was 64.Speedo first,sat-nav second. & for James-uk, 92 degrees!