1 hour ago, Yellowtail said:

Why?

Just look at the space requirements for the rotors and callipers it will be obvious 

1 hour ago, malathione said:

Yes, improvements do exist, certainly. As for tire testing data, https://www.tyrereviews.com/ is my usual go to. In fact, I remember now they did a test on exactly what you're planning to do a few years ago, a direct comparison between different rim diameters.

Is this the review as far as you remember 

 

6 hours ago, sometimewoodworker said:

Is this the review as far as you remember 

 

Yes, that's the one with the Golf. There is a companion written piece, as well; my preferred format.

18 hours ago, sometimewoodworker said:

And you are making comments that have no value or bearing on the actual question posed

If the roads are so poor that the difference is indiscernible then my comments are relevant.....why are you so het up?

Just now, Will B Good said:

If the roads are so poor that the difference is indiscernible then my comments are relevant.....why are you so het up?

Actually, the roads seem pretty good to me, but in any event, if you actually knew anything about cars and tires, you would know that the difference becomes more pronounced as the roads get worse.  

 

That said, tires likely do not make much difference on your Scoopy. 

Reading all the comments seems to me that everything has been covered.
 

There is really only one way that you will know, so go for it. If you don’t like the new configuration then change it back.

 

We have low profile 19” tyres on our car, the ride is hard. I know many have changed to 17” or 18” with a huge improvement.

 

I changed from RFTs to conventional Pilot Sport4 and quite an improvement. I wanted Primacy but they were not available in the size I wanted unfortunately.