MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Comms on April 08, 2011, 01:55:50 am

Title: Switching between different size alloys
Post by: Comms on April 08, 2011, 01:55:50 am

Odd question for you lot.

I was wondering if anyone here switches between two different size alloys in the year i.e winter tyres on 17's and summer tyres on 18's?

Would make sense to just stick with one size for sure but I was thinking of this as a possible option for myself but would this mean recalibrating the speedo each time I switch over?

(Dons the flameproof suit  :scared:)

Title: Re: Switching between different size alloys
Post by: stealthwolf on April 08, 2011, 01:59:59 am

I think as long as you have the correct profile tyres, the rolling radius will be near-identical so the speedo should remain accurate. It's worth sticking winter tyres onto the 17" rims as they kick in below 7*C (I think).

Title: Re: Switching between different size alloys
Post by: the bruce on April 08, 2011, 09:07:58 am

If you stay with stock tyre sizes the speedo remains the same.
225/45 R17 and 225/40 R18 are nearly the same outer diameter.
17" and 18" is just the inner tyre diameter ( = rim diameter).

17" for winter and 18" for summer is very fine.

Have a search on the forum if you want aftermarket rims (remember offset
should be between ET45 and ET50). Or go for OEM wheels.

Title: Re: Switching between different size alloys
Post by: RedRobin on April 08, 2011, 09:19:26 am

.
The OEM speedo is grossly inaccurate anyway. Car manufacturers are allowed up to 10% inaccuracy on the plus side. Mine has been checked with several systems and when displaying 100mph I am actually travelling at 87mph!! The higher the speed the more inaccurate  :fighting: This is why I rely on GPS and a large digital numeric display.

Title: Re: Switching between different size alloys
Post by: Jaywoo-GTI on April 08, 2011, 09:34:25 am

I switch between my summer 19's and winter 18's only adjustment i make is the ride height on my coilovers.

Title: Re: Switching between different size alloys
Post by: the bruce on April 08, 2011, 10:51:47 am

I switch between 17", 18" and 19" almost every week.  :wink:

Only adjustments:  damping/shocks and ARBs.  :drinking:

Title: Re: Switching between different size alloys
Post by: Comms on April 08, 2011, 03:11:46 pm

Thanks for the info, don't feel like a muppet now  :grin:

Didn't really want to waste my winter tyres on my 17's.

I will start looking for some 18's now, had some RE's from Oettinger in mind but then again im always changing my mind!

Title: Re: Switching between different size alloys
Post by: the bruce on April 09, 2011, 10:34:25 am

Go for some used 18" Monzas or BBS. Always looking good on any GTI.  :wink: