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stu



Member Since: 04 May 2011
Location: Richmond North Yorkshire
Posts: 927

United Kingdom 2012 Range Rover Vogue TDV8 Orkney Grey

Had a fiddle done some sums and been for a drive with my garmin fitted. Using the garmin and the digital speedo on the dash, my speedo reads spot on with the garmin over a variety of speeds.

Below are the before and after settings. The 255x55x19 is an error as they were originally 50's!


Click image to enlarge


Click image to enlarge

Got images wrong way round! Embarassed Current: TDV8 (3.6) RRS HSE



Past: TDV8(4.4) Vogue
Discovery 3 Commercial
TDV8(3.6) Vogue
TD6 Vogue
D2 V8 ES
D1 V8 ES
RR Vogue Classic

Post #438261 13th May 2017 1:21pm
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GAC23



Member Since: 27 Nov 2013
Location: Herts
Posts: 670

United Kingdom 2015 Range Rover Vogue SE SDV8 Indus Silver

stan wrote:
not sure what you mean Stu...there's a part in the iidtool cff that lets you put in your wheel size and because i have recently changed from 20" to 21" i imputed 21"...
nit sure if this change makes a difference but it hasn't given me any warning lights on the dash..


Because I learnt this yesterday from the everso helpful Patrick @ GAP:

Only the Rolling Radius ABS mm will change the speedo, ignore the other ones
 What do I put here then?

Post #463973 10th Jan 2018 9:51am
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stan
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interesting Thumbs Up ... - .- -.




click link for ,

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workshop manual downloads are in our wiki

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Post #463975 10th Jan 2018 9:57am
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GAC23



Member Since: 27 Nov 2013
Location: Herts
Posts: 670

United Kingdom 2015 Range Rover Vogue SE SDV8 Indus Silver

Only problem is how to calculate the rolling radius.

IE allowing for the tyre deformation due to the weight of the FFRR.

I found this link: http://paws.kettering.edu/~amazzei/tire_calculator.html

The figure I got is 12mm less than I'd worked out for the static radius.

This fits the 8 - 12mm difference (between static and rolling radius) I'd seen when looking at the sizes in the IID tool's settings for Rolling Radius ABS mm.

And driving past some of the roadside thingies which show your speed suggests my speedo is working right. What do I put here then?

Post #463978 10th Jan 2018 10:19am
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Grofus



Member Since: 24 Mar 2017
Location: Co Clare
Posts: 577

Ireland 2007 Range Rover Vogue TDV8 Zermatt Silver

Stu, I don't think the 50s. are standard on a 19" rim. 55s are . 2007 Vogue TDV8 in Zermatt Silver with Charcoal

Post #464004 10th Jan 2018 2:13pm
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stu



Member Since: 04 May 2011
Location: Richmond North Yorkshire
Posts: 927

United Kingdom 2012 Range Rover Vogue TDV8 Orkney Grey

GAC23....

Does this help?

http://www.mkivsupra.net/vbb/showthread.ph...re-Profile Current: TDV8 (3.6) RRS HSE



Past: TDV8(4.4) Vogue
Discovery 3 Commercial
TDV8(3.6) Vogue
TD6 Vogue
D2 V8 ES
D1 V8 ES
RR Vogue Classic

Post #464018 10th Jan 2018 4:52pm
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GAC23



Member Since: 27 Nov 2013
Location: Herts
Posts: 670

United Kingdom 2015 Range Rover Vogue SE SDV8 Indus Silver

Thanks, Stu.

But that figure assumes the tyre is perfectly round.

Which, of course, with a FFRR sitting on it won't be true Smile

The link I used - shown above - allows for this squashing. What do I put here then?

Post #464024 10th Jan 2018 5:08pm
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Alistair



Member Since: 11 Feb 2011
Location: Peterborough / Bordeaux / Andorra
Posts: 7724

United Kingdom 2013 Range Rover Vogue SE SDV8 Santorini Black

I’d just use trial and error and a GPS

Adjust the iID setting until it’s showing the right speed

Post #464042 10th Jan 2018 6:27pm
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