bigger wheels make it slower?

[LaserBlue]

is this true??

reason i ask is last night i drove my mates gti all standard like mine but with 17s

soon as i started driving i could tell straight away how much the comfort changed compared to mine with 18s on then after a while i i went home and mine felt slower?

its hard to explain what im saying but with the 17s it seemed faster and defo more comfortable.

mine did come with 17s since i had the 18s i noticed more rattles..

anyway id already put my s3 alloys up for sale few days ago

thinking of putting the 17s back on as i commute to work on the motorway and i want that smoother ride back.

[pulp58]

Not sure about this.

I remember reading that the Astra VXR's official 0-60 time could only be acheived with the optional 19" wheels, so there was an obvious benefit with that car of having large wheels.

I would have thought performance wise regarding pace, it was the same, handling - bigger wheels should have benefit. Ride - 17"s would be best as you found with your mates! 
 

[NewGolf]

I chose 17"'s over the 18"'s after reading about it on a GTI review. It's definatley a smoother ride, although the car doesn't look as mean!

[R32UK]

I remember reading an article in some magazine where they tested to see of bigger wheels made your car any faster. Round a track the smaller wheels came out on top. It was quite an extensive test but was a while ago so my memory is a little vague. Definately something behind that theory is what they proved.

Stupid stupid memory

[LaserBlue]

because the wheel has a bigger circumference it takes that little longer to turn therefore being slower than a smaller wheel which will turn quicker and stop faster?

kinda what im thinking??

 

[CocoPops]

What tyres are fitted to the 17s and 18s as standard?
ie are the rolling radii the same?

[bobotheclown]

Theoretically, if you have a hub spinning at 100rpm, a tire with a 20-inch outside diameter would propel the car twice as fast as a tire with a 10-inch diameter. In actual practice, installing larger tires on a car, will make it accelerate much slower, but increase your top speed, if your vehicle has the horsepower to push it. A new wheel that is 8% larger than the old wheel, will push you 4mph faster at the same wheel speed. - From Yahoo Answers (quick google search)

Upshot, faster top end speed, slower acceleration.

[NewGolf]

I think the 2 wheels, 17 inch and 18 inch have different profile tyres, so the rolling radius(!) should be identical. If it wasn't the speedo would be out?

225/45/17 as opposed to 225/40/18  I think from memory ?

[Cass]

I think the 2 wheels, 17 inch and 18 inch have different profile tyres, so the rolling radius(!) should be identical. If it wasn't the speedo would be out?

225/45/17 as opposed to 225/40/18  I think from memory ?

Correct.

Cass

[LaserBlue]

yes thats correct about speedo out..

i had 225 40 18- 8j on my old bmw and my speedo said 30 but i was doing 32!!

so smaller tire = faster acceleration - bigger tire = better top end speed

18s look nice but i think i will be going back to the 17s..