I have a question to ask for a friend.

He has 205/55/16 size tyres on a car which is lowered 40mm

The front tyres are catching the arch under heavy cornering or when he throws the car around on the front.

It is fitted with a Spax PSX? spring and shock combination.

He is contemplating fitting 205/45 size tyres to the alloys, but has seen some 17 inch alloys he likes, which already have 205/40/17 tyres.

Question may be daft but would the 205/40/17s be bigger or smaller than his current 205/55/16 wheels? The 16 inch wheels have been refurbed using filler and my friend is worried when they change the tyres it will ruin the wheels.

Thanks

 

What car it is would help. That size on a Focus would be different to an Austin Metro

 

Focus ST170, 2 door.

Thanks

 

Surely a 205 is a 205 whether it's on a Focus or a Metro!

205/45x16s have a diameter of 590mm and circumference of 1854mm
205/40x17s have a diameter of 596mm and circumference of 1872mm

 

Funny fucker You know exactly what I mean

205/40/17's should be fine on the Focus but an ST170 should have 17's anyway and run 215/40/17 iirc. Worry about the wheels being the correct offset before looking at the tyres, even with right tyres if the rims aren't right you're screwed

 

st170 runs 215/45/17 standard

 

I run 215 45 17 on mine lowered 30 mm and it gets thrown about a lot. never heard a rub

 

We are trying to work out the best offset for the focus ET wise, which will still fill the arches its got mondeo 16 inch 5 spokes on at the moment with 205/55/16 tyres as his Mrs drove it over a motorway exit roundabout in the snow and wrecked 3 of the standard 17s! He got replacement suspension for it but is unhappy as the back sits higher than the front and wants to fit coilovers and lower it so theres around a finger widths gap from tyre wall to arch all round? Not sure whether to buy another set of ST170 alloys again with low profiles or is there a better offset for lowered focus's ?

My wifes Focus sits too high at the rear too even though it is standard, must be a common Focus issue.