I've got 255 50's on my 20" wheels but have been offered 245 45's at a decent price.

If I fitter slightly narrower tyres would they:

A) fit the wheels ok
B) make any noticeable difference to road holding or performance?

Obviously wider tyres are a bit more stable but is the difference that critical?

They will make the wheels look like they don't fill the arches

Hmm not that great then?

The ones I'm selling are the ones to go for …but you would be 3rd in the queue at the moment

Lol you crafty old devil. Won't the 45 s improve the economy of the car?

Not sure …I'm sure someone on here has pictures with sport wheels on there ffrr it looks wrong IMHO
Each to there own

About 30mm difference in sidewall height. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

So would that make the car slightly lower?

Would probably also invalidate your insurance, unless you told them, in which case it would most likely increase your premium......

And possibly give you a harder ride with less tyre wall to run on and "soak up" some of the bumps Ash
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2016 SDV8 AB

I have winter tyres 235/65 R18 and normal tyres 255/55 R19. I notice naff all difference in ride/handling/mpg.

They're both big tall squashy tyres so it's hard to tell much difference.

My sports car with different tyre widths made a huge difference to ride/handling/mpg.

Maybe those with 20's or bigger wheels will notice a bigger difference but on 18's and 19's it's hard to tell.

Would make the wheels look like they dont fill the arches properly. Wheel would be 2" smaller overall. You are not only reducing the aspect ratio (50-45) but also the width 255-245 so double whammy. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

I'm thinking maybe not great then.

Can believe no one has fitted these to their FF...

Standard tyre size: 255/55 R 19
Total wheel diameter (mm / in): 763 / 30
Percentage diameter difference to the original (%): 0

Standard tyre size: 255/50 R 20
Total wheel diameter (mm / in): 763 / 30
Percentage diameter difference to the original (%): 0

Suggested tyre size: 245/45 R 20
Total wheel diameter (mm / in): 729 / 29
Percentage diameter difference to the original (%): -4.5%

That’s 4.5% smaller rolling diameter, and that’s a lot!

Rand that's great.

Thanks for the info.