okay, I am going to ditch the RFT, and getting NON RFT! These RFT jumps when I break harder (ABS not kicking in yet)

Has anyone try 255/40/18 insteadl 245? would it be too wide? thanks

 

Your adding 5 mm to each side. Perhaps

 

too wide, no?

 

Perhaps needing some spacers....I am sure a few of our resident experts will chime in soon.

 

There's no good reason to go for 255/40 18", go for the OEM (245/40 18").

But you can also buy ie the Styling 124 wheels. (I suppse you what the Style 123 now)?.
This way the rear tyres would be 275/35 18" but the FW still 245/40 18".

 

why would you what wider tyres when 245 are veryOK and good.

 

Same reason you wanted different tail lights I presume. No reason to do so whatsoever.

 

wider the tire can protect the rim a little better. am I crazy?

 

well yes, if people need protect the rim, then they are bad drivers and should not get big rims

 

255's may be too wide if you're mounting them on an 8" wide rim (stock 123's). Check with the tire manufacturer to see what they recommend. I think most tire makes suggest a minimum of an 8.5" wide rim for 255 wide tire of that profile. You would also end up with a (very) slightly taller tire. I would use 255/35x18's on the 530 if I were going that route.