7.5J 125 vs 8.5J 135

[P6GTD]

Can anyone give me real life experience of difference in any/all respects by changing “up” from standard 18”Parkers to after market alloys?

I’m thinking about ride, handling, road holding, noise, tramlining. Better, worse, same?

I should add that the Parkers weigh 13.3 k and the after markets weigh 9.7k per bare wheel.

The 8.5 rims are extremely strong in case anyone comments.

(I still swerve wildly between doing nothing and changing….. it’s hell I tell you!)

[rowlers]

I've moved to 18'' CM Prets for summer, kept the Parkers for winter.
The CMs from memory they weigh 10~ kgs. they are 8J (not 8.5 sorry) and I went with 235 tyre, Kuhmo Ecstas. They reduced my mpg from around 45 to around 40 on my usual work commute.
Gone back to my Parkers for winter with BF Goodridge All season tyres and I'm back up approaching 45mpg
The ride is much plusher on the CMs/235 tyres, grip appeared to increase, handling more "wafty",  but direct.
Noise, no discernible difference.
Tramlining no difference

Not sure if this helps you!?

[P6GTD]

Thanks.
I’m wondering if the significant reduction in bare wheel weight offsets any negatives in the wider wheel/ tyre combo?
I always understood that a reduction in unspring weight was always positive.
I’ve decided to make my 7.5 Performance a keeper.
And I like to do something good every year.

[willni]

I always understood that a reduction in unspring weight was always positive.

Aluminum subframe and lightweight discs next 

But to answer your question it makes a massive difference, I generally worked off 1kg of unsprung weight was equal to 4kg of sprung, some people go up to 8kg others 2.4kg. My car feel far more dynamic with a 7.5kg (Bare) Belvedere alloys on it, I regret selling them and not just putting PS4S' on them for summer.

[rowlers]

I always understood that a reduction in unspring weight was always positive.

Aluminum subframe and lightweight discs next 

next on my list too, once I've finally get the new calipers on

[P6GTD]

Thanks for replies.

I suppose the point of my original question was less about wheel weights and more about rim and tyre section changes. What positive or negative effects would be noticed by “going wider”?

[Exonian]

Looking specifically at MQB Golfs, I’ve changed numerous times to 235’s on an 8” wide wheel from the original 225’s on 7.5”

Pro’s are looks, looks and looks. Oh, and a slightly sharper turn in.

Negatives are a slightly knobblier ride and dearer tyres

Aside from that there aren’t huge differences in feel. Use decent tyres and there’s no extra torque steer, no tram-lining in my experience and no discernible difference in steering weight.

I haven’t tried 8.5” wide wheels though.

[P6GTD]

Thanks for all that. I wonder if the substantially reduced wheel weight of my proposal would offset any negatives arising from running 8.5/235.

They would certainly reduce the weight of my wallet 

There’s only one (very expensive) way to find out.

Meanwhile, if any other members have a view, please contribute.

[EB2019]

I notice the difference between PS4 and GY ASM6 on the same width, GY ASM6 being sharper, with slight less cushioning, better continuous corner speed without squeal too. So tyre brands play a big part in feel, probably more than size of width if its not extreme. Width as Exionian says doesn't have many negatives, but I would say brand plays a bigger part in it all.  Think a set of ditch finders vs Cup 2 R, I wouldn't care what wheel and weight,  the thing in contact will most likely transform the dynamics.

One other item to consider is scrub radius if you change to aftermarket wheels and the offset changes. This makes a difference to braking stability and feedback, tramlining feedback will also change. No personal experience as I try to keep offset within mm of original to reduce any big scrub radius changes, but this will depends how sensitive you are to it I guess.

 

[P6GTD]

Interesting post, thanks.

The outlay on these 8.5J rims is too big a financial risk to get wrong so would I would revert to 8.0J 225 section which is not too great a departure from standard Parkers I think. Or do nothing!