[VWBob]

The tire is only 10cm (1/2") wider but the overall diameter of the 275/45/19 is 28.7" to the 265/50/19 being 29.5", you need to do 4 new ones at same time and your speedometer may be off.

I think others have done this, maybe somebody will confirm.

 

[VWBob]

The Nokian WRG3 seems like you are looking to get a tire that has improved winter performance like a snow tire but can be driven all year round, do you get a lot of snow where you are in NJ ?

Toyo makes a similar tire in the 265/50/19 size https://www.treaddepot.com/#!productDetail/tireStandardFitment/128160 https://www.toyotires.com/tire/pattern/celsius-cuv-variable-condtions-tire-0

I would not go an 1" smaller in overall diameter, there is a lot of room in the wheel well to fill up and you may be surprised how small going only 1" smaller overall diameter may look when all 4 are on the Touareg.

Is there an option in your preferred tires that has a slightly larger overall diameter?

If you are not towing regularly the changed final ratio for cruising at highway speed will not be a factor