Stretch tyres and lowering

[mashmarriner]

Am wanting to buy 17 by 7" alloys but I also want to slam the car so I guess I will have to stretch te tyres jw if anyone knows what tyres I should get for this and how much for them and how much to fitt them

Also how far should I lower it to get that euro look

[B1N9S]

If you dont "slam" the car too low, these size wheels will be fine with 215/40 tyres and your car will still retain some street cred !!!!

However, if you do want to slam it for shows or whatever ! Then I would go for something like 185 tyres or even 175 on those size rims. But getting 185/40 tyres ?? might be a struggle.

If you get a different sidewall size, then your speedo will be out, as you will be altering the rolling radius of the wheel.

[mashmarriner]

Cheers bud. It not for shows. Not yet anyway. Thinking of getting it lowered by bout 50m. Just something low but not too low not yet. N have nice 17s on. Looks like I may nit have to stretch the tyres this way.
As I have a mate with a seat ibiza n he has 17. Nhas lower by 50 and wheels are 205/45 a think so am sure the polo bout the same as they may as well be the same car

[B1N9S]

The correct tyres on the 6R Polo are 215/40/17.

A 45 profile tyre will knock out your speedo !! It will make the speedo report a slower speed than your actual speed !! Not sure how much, but round here it doesn't have to be much for a speeding tax fine to appear through your door.

[mashmarriner]

Spot on bud cheers

[mashmarriner]

Also have one other question. This is an example just to understand if I can fit larger wheels

Say I lower the car on my standard 195/55/15 this makes the diameter 595.5 . And is lowered by 60mm n is 10mm away from the tyre (example, a dunno weather this would be correct)

I then get 195/40/17 this makes the diameter 587.7. Dose this still mean I will still be able to make the car lowered by 60mm and this would then 20mm away from the tyre or just about.

Or if I am wrong can someone please explain. Coz I want to lower the car but wen it comes to get larger alloys I still want the car to be just as low.

[B1N9S]

What is "n" ?

[mashmarriner]

What is "n" ?

Short for and x

[blazeguarder]

If you reduce the sidewall depth then you will have less tyre between the wheel and the road so the car will sit lower anyway. If I'm reading your example right, then by changing the tyres you'll increase the arch gap but the car will sit lower?.

Bear in mind with those tyres though that you'll have some stretch going on - 17" wheels will be wider than 15" ones. Best not to mess about with tyres/rolling radii though. Not worth the effort of dealing with the speedo issues that you'll have.

Sorry if I've read your example wrong mate, just looked back over it and had a massive mind blank. Been a long day...

[Hurdy]

Your calculations are correct Mashmarriner. Although a 195mm tyre on a 17" alloy will be quite a stretch indeed as they will normally be at least 7" wide alloys.

[Edi30]

Yup rolling radius of the overall tyre is key to ensuring that the gearing and speedo stay within a reasonable %. I looked at fitting 18's to my Polo and worked out that 215/35 18's were within 3% of the standard 215/40 17's. As my speedo in standard trim over reads by about 5% fitting the larger wheel/tyre combination would actually make speedo read more accurately.

I have decided to keep the standard sized wheels as I like them. Good luck with what ever you go for

[mashmarriner]

Cheers people I understand now. And btw the wheel I want will be 7". So I think am not going to bother stretchin the tyres as I have been doing research and people are having too many problems with them so just have 215 so the wheels sit flush with the arches