Tyre sizes (again)

Not long bought a 2000 Td5.
The tyres on it are 255/60 18.
Now, everywhere I search/look/ask/read tells me the standard size is 255/55 18.
What, if any, difference does the extra 5% height make - speedo reading, handling etc. Other than the price.

Thanks in advance, Ozzy.

(Now all I have to do is, wait expectantly for informed answers to roll in, without any sarcasm at all)

Bugger all.

Excellent.
The 60's are cheaper than the 55's.
No I don't know why either.
Thanks

Your speedo will be 3.71% out, so at shown speed 70 you`ll actually be doing 72.6. In the real world this is approximately, but not exactly, bugger-all. (figures from www.carbibles). Now i gotta get my anorak out the tumble dryer and iron it before I go out train-spotting.

So is that 3.71% better or worse mpg ?
:behindsofa:

Don`t work like that ! Fitting a bigger wheel = higher gearing is sometimes better, and sometimes worse (gotta change down a whole gear earlier). If upping the gearing meant more economy the factory would do it.
Plus 3.71% still equals approximately bugger all, in the real world.