tyre and wheel size

[noosh]

Hi, I've often looked through the news on this site so thought I'd join to ask a question. So on that note, hello.

I've recieved a new set of wheels for my car, however theyve arrived with the wrong tyre size, they've fitted a different smaller width tyre.
Now I'm no engineer, mechanic, tyre fitter, hell I strugle to change the oil so am wondering when these go back, and they will, will the wheels have to be changed or altered to accomodate the wider tyre size?
20mm for reference.

[Watchman]

Hi, welcome.

It'd be easier if you could tell us what size wheels and tyres your car normally wears, and what you've received.

[noosh]

Yeah looking at it that might have helped haha.

Tyres should be 225/55/15 I have had delivered 205/50/15.

[Nick3point2]

What width are the wheels?

[jagracer]

noosh said:

Yeah looking at it that might have helped haha.

Tyres should be 225/55/15 I have had delivered 205/50/15.

What width wheels do you have? Ideally you want 7 or 8 inch for 225s 6 or 7 for 205s
What car are they going on?

[noosh]

Wheel width is 7

[jagracer]

225s will be fine on 7inch rims, I take it you are aware of the quite large difference in rolling radius and ride height between the two sizes.

[kambites]

Seven inch should be fine for 225/55s, I think.

[noosh]

jagracer said:

225s will be fine on 7inch rims, I take it you are aware of the quite large difference in rolling radius and ride height between the two sizes.

Yes. Well, not maybe the technical stuff but I'm very aware theres a difference in how they feel.

And comparing the difference in those terms between the 225 and 205 the car feels better, grippier and me slightly more confident in driving with the 225 over the 205.

[jagracer]

What size wheels and tyres do you have fitted at the moment?

[CoolHands]

Difference in Diameter: percentage = -6.69 % which is 42mm

±2.5% is the MAXIMUM difference recommended (apparently) so it looks a bit much.

[jagracer]

CoolHands said:

Difference in Diameter: percentage = -6.69 % which is 42mm

±2.5% is the MAXIMUM difference recommended (apparently) so it looks a bit much.

Yes but it depends what he's changing from.

[noosh]

At present 225/55/15

[CoolHands]

jagracer said:

es but it depends what he's changing from.

well they "should" be 225/55 so obviously that's what I used?

[noosh]

CoolHands said:

Difference in Diameter: percentage = -6.69 % which is 42mm

±2.5% is the MAXIMUM difference recommended (apparently) so it looks a bit much.

So given the 7 inch wheel I'm assuming from your point of view its unlikely they'll direct re-fit?

Or is that more, if the car is running 225 now, which it is, the 205 will have a greater effect on the car?

[jagracer]

noosh said:

So given the 7 inch wheel I'm assuming from your point of view its unlikely they'll direct re-fit?

Or is that more, if the car is running 225 now, which it is, the 205 will have a greater effect on the car?

225s will make no difference as you are changing like for like. If you put the 205s on, your speedo will over read which legally isn't a problem, the car will rev higher for a given true speed and will be slower overall although acceleration should be better.

[noosh]

Brilliant, somewhat confounds my reasoning behind them being like for like if they decide to have an argument over the tyres they fitted.

So from the original q, theoretically then there should be no issues with them simply taking the wheel and placing the correct 225/55 on them? given the wheel is 7 wide.

[jagracer]

noosh said:

So from the original q, theoretically then there should be no issues with them simply taking the wheel and placing the correct 225/55 on them? given the wheel is 7 wide.

No problem at all providing the offset of the new wheels is correct and they don't foul anything.

[noosh]

Brilliant thanks.

Probably sound like a complete idiot on all this lot.

[jagracer]

noosh said:

Brilliant thanks.

Probably sound like a complete idiot on all this lot.

If you don't ask you don't learn.