Wheel size performance advantages?

[Busterboo]

What performance advantages do 19" wheels have over 18"?

[Player 1]

The wheels themselves? Unless they're lighter than those they're replacing then the absolute square root of jack.

If you can get bigger brakes in under there however then you can stop quicker, or at least stop just as quickly for longer.

[tadekk]

The wheels themselves? Unless they're lighter than those they're replacing then the absolute square root of jack.

Not wheels necessarily, but different tyre profiles will affect handling according to this guy

[warmasice]

19" are better because they cover more distance for each rotation. Also, the 326 wheels give an extra 50 bhp.. per wheel.

[Mr Tidy]

19" are better because they cover more distance for each rotation.

Except they don't if you use the OEM tyre sizes, otherwise the speedo would be wrong!

But if you use run-flats you'll probably be able to damage more wheels on 19s.

[flybobbie]

I thought lower profile was to reduce side wall flex so better grip?
But RFT total negate the need for low profile as they already ride as though they are made of wood.
Going to normal one can feel the car is more stable as the flexing allows the car to compensate for minor road irregularities.

The extra inch, so she tells me, doesn't make much difference if anything a harsher ride.

[Lazza]

Reducing tyre flex improves steering response but loses grip. Grip comes from maximising contact patch and keeping it in contact with the tarmac and tyres with more give in them do that better. That’s the main reason non run flats are so much better than run flats.

[Busterboo]

Articulate, intelligent and persuasive.

[Jembo]

Typically 19” wheels are heavier than 18” by a noticeable margin (unlike 17/18” weight difference) - that was my experience with AUDI wheels.... which translates into less fuel efficient.

If you look at the same new car with different wheel sizes, the CO2 emissions are different & am sure it has to do with this

[Valor1]

If you research wheels, like HRE and some BMW wheels, you can find lightweight 19 or 20. My 20 weigh less than the OEM 19.

[Smartbear]

If you research wheels, like HRE and some BMW wheels, you can find lightweight 19 or 20. My 20 weigh less than the OEM 19.

That maybe true but surely you could find some smaller wheels which were lighter than your 20”s?
Rob

[sunnydays]

If you research wheels, like HRE and some BMW wheels, you can find lightweight 19 or 20. My 20 weigh less than the OEM 19.

Nice looking car! Alloys look good.

Any more pics? Additionally what tyre sizes are you running with those alloys

[Nictrix]

Typically 19” wheels are heavier than 18” by a noticeable margin (unlike 17/18” weight difference) - that was my experience with AUDI wheels.... which translates into less fuel efficient.

If you look at the same new car with different wheel sizes, the CO2 emissions are different & am sure it has to do with this

Surely they should be weighed with tyres fitted to find out a true difference.
The wheels alone will be heavier but surely the tyres will be lighter as there is less rubber due to smaller sidewall if you go for standard sizes.
Or am I talking crap?

[Valor1]

If you research wheels, like HRE and some BMW wheels, you can find lightweight 19 or 20. My 20 weigh less than the OEM 19.

Nice looking car! Alloys look good.

Any more pics? Additionally what tyre sizes are you running with those alloys

Thanks. Tires are Michelin Pilot Sport 4S 255/19" front and 285/20" rear.

[Ewazix]

Reducing tyre flex improves steering response but loses grip. Grip comes from maximising contact patch and keeping it in contact with the tarmac and tyres with more give in them do that better. That’s the main reason non run flats are so much better than run flats.

At last, someone who understands that tyre/suspension systems NEED controlled compliance to maintain grip, beyond a certain point bigger wheels, lower profiles and lower/stiffer suspension will do squat for performance on real UK roads