Wheel upgrade: Performance decrease?

[blackturbo]

Just wondering how much effect if any going from 195/45/16s to 205/40/17s will make?

I know there is a site out there which calculates the difference but i'll be damned if I can find it!

 

[Dan Cupra R]

I know this is different but i went from 15's on my corsa to 17's with 205/40/17 tyres. Whilst they looked nice it didnt do teh car any good. When ever i put my foot down in the old corsa it would wheelspin but the wheels would sound like they were jumping up & down making a horrible banging sound where the wheels were too big for my car. Not sure whether this would be the same on a Beezer but its put me off getting bigger wheels for my Cupra

 

[blackturbo]

Well I know that lots of people have gone from 16s to 17s as the rolling radius (think thats right!) isnt much different, just wanted to check

 

[Dan Cupra R]

Well I know that lots of people have gone from 16s to 17s as the rolling radius (think thats right!) isnt much different, just wanted to check

Some companies also do "lightweight" alloys so u could probably go bigger without extra weight.

 

[Ibiza Cupra]

No it will be fine. Your wheels probably jumped on your corsa as there wasn't enough power to spin them!!! Look how many people r running on 17's. You have to get 17's if you want to make your brakes bigger.

 

[Tony 156]

Done this before on an rover 200 vi, wrecked the acceleration, top speed and handling.

The theroy is bigger wheels, less acceleration but higher top end. it showed alot on the rover but it didnt have the power to get over the extra 1. weight 2. radius difference.

ive recently put standard wheels back on my ibiza and i will say its not as diferent as i thort. acceleration is a bit better, top end is better and the handling is now a hell of alot better.

of course this is depending on mods as well, engine suspension etc.

possibly a bit of useless info, but the lower the tyre profile the more likely you are to wheel spin off the lin. a slightly bigger tyre profile has a bit of give in it so the initial power is taken up in tyre flex. this then means less spin and a better launch.

The key to wheels is light wieght, decent tyre and what looks good.

 

[andythom]

Theres hardly any rolling diameter difference between 45/16's and 40'17's....litrally a few mm's.....you wouldn't notice the difference

 

[Dan Cupra R]

No it will be fine. Your wheels probably jumped on your corsa as there wasn't enough power to spin them!!! Look how many people r running on 17's. You have to get 17's if you want to make your brakes bigger.

How bigger you talking? Ive got bigger brakes on my R & the 16's fir round them fine

 

[Bogwoppit]

The 195/45 R16 have a rolling diameter of 581.9mm
The 205/40 R17 have a rolling diameter of 595.8mm

This means your tyre/wheels will be growing in diameter 2.3%. This will affect you speedo causing it to under read but as speedos over read anyway it should be fine.

As the tyres are wider this will actually reduce you top speed as you will have more friction and drag.

The 17s will also increase your unsprung weight as they will weigh more thus slightly decrease you acceleration. Unless you go for expensive light weight alloys.

But they will look better, increase you cornering grip and allow bigger brakes to be fitted.

The choice is yours

 

[blackturbo]

Well they are Inovit Light weight ones

My speedo already under-reads or does according to Sat Nav but my sat nav is poo anyway lol!

 

[Bogwoppit]

If the speedo shows 65mph when you are actually travelling at a GPS verified 60mph that means your speedo over reads, ie it reads high.

 

[blackturbo]

No I mean the Sat Nav shows say 65 when speedo shows 60!

 

[Bogwoppit]

Thats very rare, either your sat nav is lying, you have small wheels fitted or your car has the wrong gearbox!
Most speedos from the factory over read by a minimum of 7%.

What sat nav have you got?

 

[PhilW]

Wont make any difference mate, as mentioned above the rolling radius is next to bugger all. And those wheels are probably lighter than the originals

 

[blackturbo]

Tom Tom, altho it was playing up like crap that day, telling me to turn right on the M3 and such lol

 

[cupramad12]

Hey lad I put some 17's on me cupra lasy tear and it really blunted my acceleration and took some of the fizz out of the car if you feel me - i sold them to my BF and now im rolling on standards again!

 

[blackturbo]

I cant imagine it making a huge difference but we will see when I get them on Monday!

 

[andythom]

the weight of the wheels will have more effect than the 16-17 size diff

eg, the standard 16's are quite heavy, but 17 super T's or legerras will be lighter ;p

 

[Ibiza Cupra]

QUOTE FROM DAN CUPRA R::
Ive got bigger brakes on my R & the 16's fir round them fine



Thats cos they are OZ supperT's . Most wheels due to the inner diameter you need 17"

 

[andythom]

There are lots of 16's that do fit though......17's are the easiest way to get wheels on with brembos etc