Page 1 of 1

Should I go from 6.5 to 8?

Posted: Mon Mar 24, 2014 3:10 am
by 22Silver
Curious to know if it feels better on a nice windy mountain run?
Current is 15x6.5 +? Rota slipstream, weighs at 5.4kg.
I can't find 15x8 rims that are less than 6kg though, so would a 7kg 15x8 feel good, compared to a lighter 15x6.5?
Kumho Ku31 all round if it makes a difference.

I really like the look of the fat wheels small rolling diameter for some reason.

Re: Should I go from 6.5 to 8?

Posted: Mon Mar 24, 2014 7:03 am
by rascal
22Silver wrote:Curious to know if it feels better on a nice windy mountain run?
Current is 15x6.5 +? Rota slipstream, weighs at 5.4kg.
I can't find 15x8 rims that are less than 6kg though, so would a 7kg 15x8 feel good, compared to a lighter 15x6.5?
Kumho Ku31 all round if it makes a difference.

I really like the look of the fat wheels small rolling diameter for some reason.

Surprising that the Rotas are only 5.4kg. Have you weighed them, or going off spec sheet?

Anyways, there are a few 15x8 under 6kg. Konig flat outs are 5.6kg, as are wide opens I think. Enkei PF01s and also 6ULs from 949racing just to name a few off the top of my head..


Depends on your definition of 'feels good'
The lighter narrower rim would make the car feel lighter on its toes (if you can use that term) but the wider rims would give more mid corner grip, and be ultimately quicker (though you'd need a racetrack and a stopwatch to really notice)

For the intended mountain road use (if you get one of the lighter 8s listed above) the difference is so small that it would just come down to more cosmetic reasons for choosing one over the other.

Re: Should I go from 6.5 to 8?

Posted: Mon Mar 24, 2014 8:27 am
by 22Silver
rascal wrote:Surprising that the Rotas are only 5.4kg. Have you weighed them, or going off spec sheet?

Anyways, there are a few 15x8 under 6kg. Konig flat outs are 5.6kg, as are wide opens I think. Enkei PF01s and also 6ULs from 949racing just to name a few off the top of my head..


Depends on your definition of 'feels good'
The lighter narrower rim would make the car feel lighter on its toes (if you can use that term) but the wider rims would give more mid corner grip, and be ultimately quicker (though you'd need a racetrack and a stopwatch to really notice)

For the intended mountain road use (if you get one of the lighter 8s listed above) the difference is so small that it would just come down to more cosmetic reasons for choosing one over the other.


Well when I was buying them, the guy couldn't tell me what they were, and I had a few options to choose from in regards to what they were, so I checked the spec sheets, and then compared them to the actual weight, so definately 5.4kg, about 500grams lighter than the 15x6 stockies! Could be something other than Rota Slipstream but I payed like $300 so I guess it doesn't matter.

So the feel between a few extra inches is not too great, and won't severely throw balance out?

Re: Should I go from 6.5 to 8?

Posted: Mon Mar 24, 2014 8:36 am
by Nevyn72
22Silver wrote:Kumho Ku31 all round if it makes a difference.


Last time I spoke to a tyre shop (2 different ones, about a month ago) they told me the KU31s are being discontinued and it's only the stock currently left in the country that's being used up......

Re: Should I go from 6.5 to 8?

Posted: Mon Mar 24, 2014 9:08 am
by 22Silver
Time to find new tires then, Ku31 were my favorite blobs of rubber so far.

Re: Should I go from 6.5 to 8?

Posted: Mon Mar 24, 2014 9:12 am
by sailaholic
If you do the same front and back it won't effect the balance.


Sent from my iPhone using Tapatalk

Re: Should I go from 6.5 to 8?

Posted: Tue Mar 25, 2014 8:05 am
by mazmad
You will notice a big difference in feel going from 6.5 in to 8 for the same size rubber. Stiffening the tyre face and sidewall improves the grip significantly.

But it will feel different, it will have a harder ride. On the track - great. On the road, depending on your setup, it may be too harsh for you.

Re: Should I go from 6.5 to 8?

Posted: Tue Mar 25, 2014 1:21 pm
by 22Silver
I'll be going wider rubbers to fit 'the girth' ; :wink:
Not a big fan of this look.
Image