So I am now cruising safely round on my winter wheels, but have noticed (unsurprisingly) that my mpg has improved quite a lot, as much as +5mpg on a 20 mile trip. This is obviously due to the different rolling radius on my 205/55 R16 steels as compared to the 225/50/17 alloys. So the questions are 1) As both these sizes are recommended for the Octavia Scout or indeed that matter for other Octavia II models(?) then can the maxidot be calibrated to take this into account? 2) How does the Maxidot come calibrated as standard out of the factory for the 16 or 17 inch option or do they adjust it to whatever is fitted to the car as the time?

On my car there is an option to enable adjustment for having winter wheels so I presume your should have it as well! Obviously, not only will it affect mpg, but also mph readings if it's not set right.

On my car there is an option to enable adjustment for having winter wheels so I presume your should have it as well! Obviously, not only will it affect mpg, but also mph readings if it's not set right.

I thought this setting was just to set the speed warning as winter tryes are generally a lower speed rating and therefore its a good idea if you are warned when exceeding this? I am aware of the mph change I recon its overreading +3mph at 50mph

You are allowed to drive 205/55/16s calibrated on 225/50/17 because your instruments show you with the 17s a correct speed and with the 16s a too high speed. Resuslting in higher mpg,

The other way round is not allowed. Standard MkII (205/55/16 or 225/45/17) with the Scout Wheel size.

In Germany in general a deviation of 2% in the rolling radius is allowed. nominal.

On my car there is an option to enable adjustment for having winter wheels so I presume your should have it as well! Obviously, not only will it affect mpg, but also mph readings if it's not set right.

Oops - I stand corrected. Never thought it would be a speed warning jobby when I already had the same thing in another menu!

Does seem a bit strange to have to ways of setting speed warnings. What I am really after is if there is a simple tweak with vagcom that can correct for a change in wheel size?

Yes, there is an adaptation value for fuel economy fudge factor that you can adjust very easily with VCDS. Controller 17 -> Adaptation -> channel 3.

So does the adaption value also correct the odometer as presumably I am registering more miles than I am actually doing?

Oh and does anyone near Tewkesbury have VCDS and be able to do this for a beer token?