Speedo calibration with IIDTool?

[Redtail]

GAP's FAQ states:

How to adjust the speedometer when fitting bigger tires (tyres)

For Discovery 3 2004-2009 and Range Rover Sport 2005-2009

Menu–Car Config–Instrument Pack–Tyre Radius

For 2010+ vehicles

Only one of the following settings will work and it depends on the car itself. Menu–Car Config–Instrument Pack–

This setting, Tyre Size MSB – IPC

Or this one, Tyre Rolling Radius (mm) – ABS

I tried with the second setting, TRR, on my 2011 D4 to no avail.
Has anyone had any success, and if so, what setting worked? (Save me mucking about!)

[shanegtr]

I've got a 05 D3 so adjusting the tyre radius worked for me

[Redtail]

Okay, you can all stop looking now. I worked it out! [bigsmile1]

I changed the Tyre Size MSB - IPC from 31 to 33. Now it thinks I've got 33" tyres, the speedo is bang on.

While I was there, I set the Tyre Rolling Radius (mm) – ABS to 370 - 255/55R19 to reflect what is actually fitted. Any change to this in my earlier experiments made no difference to the speedo.
As an aside, this was originally 371 - 255/50R20. Not surprising as this is what shows on a VIN check via Topix.

... one more bit of info for the Starship's knowledgebase.