smaller vs larger wheels - Whats the diff?

[Spokane540iA]

I'm interest in what having smaller vs larger wheels do?

I know if you like 20's you like the way they look. That's not what I'm asking about.

What are the performance differences, what performs better? Why?

What are the trade offs?

My Sirocco 16V, back in the 80's I believe had 14's instead of 13's. My Subaru Outback has
15's as opposed my old Legacy Wagon which had 14's (instead of 13's)

My 540 has 17's (as opposed to the 16's it came with) My friend 2006 M4 coupe has 18's.

Can anyone help me? Is it just fashion?

I know there are issues with sidewall width, unsprung weight, and so on.

But I have not found a definitive answer!

Please help if you know, (and please don't answer if you don't)

[Kredithai]

You lose some performance with bigger wheels. Plus your speedometer will be off a bit as you go bigger.

[losser187]

With bigger wheels you have less tire and that means less tire roll

[GunnerNell]

It's mostly style, IMO. Wheel sizes have been getting larger and larger over the past 5 or so years. I find myself liking the bigger ones, too, but then again, I'm a fashion whore about some things.

[Sniz]

With bigger wheels you have less tire and that means less tire roll


which is not always a good thing btw

the less your tires can roll on the wheel the more your contact patch will lift during hard turns, the less your sidewalls can flex on a hard launch.

the super stiff sidewalls are ok on really heavy cars (pretty much any modern BMW) as the extra weight will help flex the very short sidewalls.

Basically, wheels weigh more than tires so overly large wheels are hurting both the straight line performance, braking, and handling of your car.

[Denwad]

the stock wheel/tire size also changes the final gear ratio ( i think :E )

[hawgripper]

The low profile tires will cause your car to run harsher than something with a taller sidewall.
The 20's look great but if you run rougher roads there is a higher chance of bending or breaking a wheel .

Suspension parts will wearout faster with the bigger wheels and lower rubber.

But you get less tire roll in corners are per previous post. Hence, less bodyroll.

My e34 runs 15"s in the winter ( smooth a silk)
17"s in the summer not quit as silky but great cornering...

[Chad17460]

Larger wheels may make your car a bit slower due to added weight and effects on gearing. Also, the larger the wheel, the lower the tire profile, so bigger wheels=harsher ride. Bump steer may become an issue with larger wheels. My advice if you want better handling is get good tires.