Why 17" 18" 19" wheels

[heyes]

I've decided to stick to 16" wheels on my v70 t5 as when I used to drive Saab 9000 aero's i had 16" 17" and 18" and apart from looks and the cost of tyres there wasn't much difference. I was wondering if anyone has any good reasons for going bigger. tyres that is.

[S60D5]

I've decided to stick to 16" wheels on my v70 t5 as when I used to drive Saab 9000 aero's i had 16" 17" and 18" and apart from looks and the cost of tyres there wasn't much difference. I was wondering if anyone has any good reasons for going bigger. tyres that is.

The only two reasons I can think of are looks or if you have silly BHP - putting the power down.

Big wheels will almost certainly cause a harder ride, will cost an arm and a leg and the tyres cost a lot more. Coupled with a noisier ride and worse wet-weather performance.

But they look good, thats the main reason

[JO5EPH]

think bigger brakes might have something to do with it??

and do 17" tyres cost LESS than 16"s??

[S60D5]

think bigger brakes might have something to do with it??

and do 17" tyres cost LESS than 16"s??

Not where I come from unless you're comparing a 17" LingLong ultra-budget crap tyre with a 16" Michelin Pilot Sport........

[Straker]

Bigger wheels and tyres (i.e. rolling radius) do actually give a better ride. However too big a wheel in comparison to the tyre and the ride degrades again.

My t5 went from the standard 205/16" to 225/17" Probably about 30mm more on the overall radius of the wheel and the ride was pretty much the same but an improvement in steering response.

18" plus wheels you will sacrifice ride compared to 16"

[pzorb]

the ride was pretty much the same but an improvement in steering response. 18" plus wheels you will sacrifice ride compared to 16"

That's certainly the consensus here, but can anyone offer an explanation as to why this is so? I've always been very curious as to how just the radius of a wheel can be so apparently significant in terms of handling - or are 16" and 18" simply heavier alloys and the size isn't the direct cause of the percept?

[mostin58]

wouldn't larger wheels affect top speed, and or acceleration?

[S60D5]

My t5 went from the standard 205/16" to 225/17" Probably about 30mm more on the overall radius of the wheel and the ride was pretty much the same but an improvement in steering response.

I have to say I differ here. I run 225/45/17 in the summer and 205/55/16's in the winter. The steering response and ride comfort is much better on the 16's in my experience.

[Mrsmopp]

When I bought my 70 it had standard 16's on, it never got traction, we beyond pants in the wet and understeer was a common occurance - switched to 17's and have better grip, NO understeer, less torque steer (albeit a minimal difference) and better traction. Plus it looks good.

x

[Phuturephantasy]

When I bought my 70 it had standard 16's on, it never got traction, we beyond pants in the wet and understeer was a common occurance - switched to 17's and have better grip, NO understeer, less torque steer (albeit a minimal difference) and better traction. Plus it looks good.

x

Yeah but what you forgot to mention was that your 16's had Ling-Long tyres on em - LOL

Only kidding.

I prefer to stick to 16's after experimenting with some larger sizes I found the ride suffered a lot, the roads around here have a lot of potholes etc and when your tyre profile is really low it makes a HUGE difference to how hard you feel it in your backside, the car suffers as well.

I think people forget just how much extra suspension and absorbance a tyre gives you. Lowering the profile effectively reduces your damping.

If you have really smooth roads like a racetrack go BIG.

[Andy]

If you have really smooth roads like a racetrack go BIG.

That'll never happen in the real world.

Most roads are ££££e!

[heyes]

Given the cost of big alloys and suitable rubber your talking £800+ I would rather spend on remap and go faster goodies.

[BlackBeast]

When I bought my 70 it had standard 16's on, it never got traction, we beyond pants in the wet and understeer was a common occurance - switched to 17's and have better grip, NO understeer, less torque steer (albeit a minimal difference) and better traction. Plus it looks good.

x

I echo that statement as well. Traction was a real issue with 16's in 2nd and 3rd gear even in the dry, changed over to 18's couple of weeks ago and i still get wheelspin in 2nd but it puts the power down much better. The downside (to some people) is the smaller height of the wall of the tyre which means I can feel every bump in the road.

To sum up, my car is now much faster with 18's as i can get most of the power down without having to lift off.

All testing was done with the butt dyno

[BlackBeast]

Given the cost of big alloys and suitable rubber your talking £800+

If you stalk all the Volvo forums and ebay and are prepared to wait for a good deal then you can get a good set of alloys for way lower than that. You could even get a brand new set without tyres from the states for half of what your talking about.

[S60D5]

If you stalk all the Volvo forums and ebay and are prepared to wait for a good deal then you can get a good set of alloys for way lower than that. You could even get a brand new set without tyres from the states for half of what your talking about.

Shipping is the killer though. They want about the same to ship as the wheels cost

[Phuturephantasy]

All testing was done with the butt dyno

Quite possibly THE most accurate device yet invented....

[the underlord]

don't be lil girls guys...

check out 19" Volution V's...

[Phuturephantasy]

They Look Fabulous - And they make the front discs look really small and feeble.

If the roads over here were half decent I'd love a set of those.

Beautiful mate..

[the underlord]

They Look Fabulous - And they make the front discs look really small and feeble.

If the roads over here were half decent I'd love a set of those.

Beautiful mate..

thanks! my 360mm x 30mm Rotors and 6 pot Wp's are on order!

49.5 lbs each wheel.. hahaha.

[Straker]

That's certainly the consensus here, but can anyone offer an explanation as to why this is so? I've always been very curious as to how just the radius of a wheel can be so apparently significant in terms of handling - or are 16" and 18" simply heavier alloys and the size isn't the direct cause of the percept?

The overall radius of the wheel (tyre and wheel) affects the ride because bigger wheels go over bumps better. If the wheel is bigger the center is further away from the bump so when you resolve the forces you get a bigger component moving the wheel up over the obstical and a smaller component decelerating the wheel.

Thats the technical explination the example is driving over a curb with a go kart wheel or a tractor wheel, which one will cope better. The tractor because it's bigger.

Once you factor tyres into the equation they become an undamped spring so if you are tackling the same square edged curbe on say a 205/55/16" the tyre will compress absorbing some of the enevitable impact. A 205/30/18" has roughly the same overall wheel and tyre diameter but less rubber so less of the shock is absorbed resulting in a firmer more crashy ride.

Because the tyres are effectively a spring they not only compress in the longtitudinal and vertical direction but also laterall (side to side) as well. Therefore when you steer round a corner the tyre has to recact these side loads and the more tyre you have between the road and the wheel the greater the deformation so you get a vague "squashy" feel through the steering wheel.

Race cars don't really care about ride comfort which is why they have big wheels and tiny tyres. Big executive barges (jags and mecs) do so they have relatively small wheels. Basically it's all a trade off so if you want good conering feel go for big wheels and small tyres. If you want to maintain some ride comfort go for smaller wheels. However overall bigger combined wheel and tyre diameter will give you a better ride.

Hope this helps.