Confused about rear tyres!

[S6PNJ]

My rear tyres will need replacing very shortly so I've searched back to see what others are using. I've also searched the TVR pages and some other references. TVR website says 235/40/18, Silverstone Performance says 245/40/18 (but recommend 265/35), Dream Machines says 225/35/18 which all kinda leaves me very confused. My handbook only gives figures for 16" wheels so I'm none the wiser for looking in there. My fronts are currently 235/40/18 (T1-S) but I've been advised that these could be causing me tramlining issues and I'd be advised to change them.
But first, I need new rear tyres. I'm looking at either Toyo T1-Rs or Goodyear Eagle F1 GSD3s (which have been recommended on this forum).
Anyone any views on sizes, issues with sizes, manufactures etc? Cheers in advance.

[lowest]

My hand book has 18" sizes which are.....245/40 on the rear and 235/40 on the front or for on "S" 255/35 all round.

[andyoleary]

245/40/18 Proxes T1-S's on my MK1 but will be changing to T1-R's when the time comes,

Andy

[NCE 61]

255/35/18 Goodyear GD3's all round on my Tuscan S.Previous Tuscan had Toyo T1S 235/40/18 front 245/40/18 rear.The wider tyres on the S seem less prone to tramlining.

[Basil Brush]

I´ve got 255/35 GSD3s on back of my Mk1 with 235/40 on front.

[lowest]

lowest said:

My hand book has 18" sizes which are.....245/40 on the rear and 235/40 on the front or for on "S" 255/35 all round.

Should have said.... Same as on the car.

[s6boy]

Basil Brush said:

I´ve got 255/35 GSD3s on back of my Mk1 with 235/40 on front.

Me 2

[Hairy Cornflake]

I have 255/35/18 Toyo T1R's all round.

[S6PNJ]

Thanks for the replies so far. Does anyone know what the impact (to stability and control etc) of having 235/40s all round would be? The fronts are currently Toyo T1-S and I'd probably look to put the Goodyears on the front and swap the part worns to the rear. Any advice, positive or negative, on this action?

[Tussie]

having 235s at the back is going to scupper traction: the back of a tuscan is light and you'll be all over the place: put 255s on the back and wear out those 235s on the front