Technically I'm tyred!

[lax]

Apologies if this has been asked before 'cause I suspect that this may be an old query, but since I'm pretty new here....

1) I'm due a tyre change - currently running S02s 255/35zr18 rr and 225/35zr18 fr

2) Can't get a full set of S02s, so looking at Proxes

3) Recommended Proxes are a higher profile tyre:
- rears are 245/40 ie 40% of 245mm = rather than 35% of 255mm for the Bridgestones)
- fronts are 235/40 instead of 225/35

which presumably means that the total wheel radius (hub radius plus tyre wall depth) is greater.

4) QED, the Proxes have a larger circumference - if my dodgy fag packet calculations are corrrect a little short of 3% bigger circumference for the fronts and about 1.6% at the rear.

Question 1 - does this mean that the Speedo needs to be recalibrated, since 1 wheel revolution will now take me further and if achieved in the same time will mean that I am moving faster than indicated ?

Question 2 - Is there any problem with fitting or running the different width Proxes to the current rims ?

Question 3 - Does the different sized tyre affect suspension/damper etc settings in any way that I should know about ?

Question 4 - what are the recommended tyre pressures for the Proxes

Further apologies where necessary for:
1) poor recollection of my 'O' level maths
2) poor understanding of the workings of a speedo
3) any other general 'dufferliness'

Cheers
Lax

[lax]

Somewhere, (I wish I knew where) I've read or heard that S03s don't stick as well as S02s or Toyos.

One of the dealers that I called came up with the same story too (unprompted).

Any experience/advice ?