Update
So I finally got my 255/35R20 Michelin PS4S’s fitted this morning. Based on a very short drive with them fitted (may be 30 miles). These are my initial thoughts so far, once I have put some miles on them I will update for those who are interested or thinking of changing tyre brand and or size.
Upside
Much smoother over cracks, lumps, bumps, potholes and man hole covers. Way less crashy as you would expect.
Significantly more rim protection.
Look better IMO, I always thought the 245/30 looked too small on the wheel and in the wheel arch.
Speedo is only 1mph off now instead of 3mph, it reads roughly 1mph higher than GPS.
Cheaper to replace tyres in this size, £60 cheaper per tyre compared to the same tyre in OE size.
No more annoying juddering on full lock.
Should have a better wear rate than the Conti’s, I expect them to last twice as long...
Downside
Steering feels slightly less sharp (will have to see how much this bothers me).
Cornering is a little vague so far (might feel better when I get used to them?).
I can feel that I am sitting higher (may be over sensitive to this?).
TPMS light came on, I have recalibrated the system (we’ll see if it comes back on?).
Will I stick with this size? Not sure yet but I would have thought so as for real world driving on UK roads in all conditions I think this tyre and size will be hard to beat.
There are some compromises of course but the upsides outweigh the downsides I think.