Change or overall rolling radius.

[KungFuPanda]

I'm currently running 255/35/19 tyres and have priced up a package of basic alloy wheels and winter tyres. I have a choice of 225/45/18 which only alter the rolling radius by 0.2% or 225/40/18 which alter it by 3.62%.

The 225/40 are obviously cheaper but would the percentage difference in rolling radius be acceptable?

[TheEnd]

Are you changing all 4 wheels?
If so, you won't notice any difference.
If you are changing just 2, you may find traction control will kick in occasionally.

[KungFuPanda]

Yeah I'm changing all four wheels but am trying to be a cheap skate with the (winter) tyres. Looks like I'll be going for the 225/40/18 then.

[xr287]

I went from 205/45/16 to 185/60/15 for winter wheels and tyres which is a 2.37% increase and I honestly can't tell the difference

[davepoth]

I'd be inclined to go down another wheel size and up another tyre profile.

[mrmr96]

davepoth said:

I'd be inclined to go down another wheel size and up another tyre profile.

Assuming that still fits over the brakes, which it most probably will unless the OP's got a mega sports car!