jimjaix

iTrader: (1)

What's the advantage of having bigger rim size? 17, 18, 19, 20? on the IS 250?

ldc

I wouldnt say getting anything larger than 18s or 19s would improve the car's performance/drivability. It's about getting the right setup for your car and this normally include suspension works...

Wider tyres and lower centre of cravity will help the car in the handling, cornering and traction department.

jimjaix

iTrader: (1)

Ok nvm I got it now

lobuxracer

iTrader: (2)

Larger diameter rims are bling. They are not mechanical performance, they are visual performance.

And before anyone tries to claim better handling through shorter, stiffer sidewalls, there are any number of tires available in 15, 16, and 17 inch sizes that outperform anything larger, especially when the suspension isn't properly tuned for the large diameter wheels. Short, stiff sidewalls need significantly different damping compared to taller, more supple sidewalls.

PhilipMSPT

iTrader: (5)

I do it for the bling...

1022it

bigger wheels are the result of the racing industry and fitting bigger brakes onto vehicles.

if you aren't upgrading brakes, thus forcing yourself to get bigger wheels, you are putting bigger wheels on for show.

your "normal driving" ride quality gets worse when you put less air between you and the road. the bigger the wheels, the smaller the tires.

just like anything else in this world, it is up to you, with what you want, prefer and choose to get for your vehicle.

i have 20's with 30 series tires (tiny sidewall), and i don't have any problems with the decreased ride quality. the good looks of a 20" wheel is well worth it to me.

zoomtt

BAHAHAHAHA Me too!!!!

uschardcor

this is like the michael moore response to the thread. only accurate in part. bigger brakes are not necessarily a cause for bigger wheels, but in some cases yes. bigger wheels (meaning bigger than what your choices were) ARE the product of marketing, plain and simple.

is4fsr

Bigger brakes are for performance(stopping capability). Compare the brake size (rotor size) of is250 vs is350. Just what most of you claim bigger wheels are only visual effects and has nothing to do with performance. Bigger wheels are heavier.

ldc

Usually if you put on bigger rims, and im not talking about 1 incher but 3 inches, then it's for the bling factor.

Wheels and brakes have no relationships other than blingness. If you want to upgrade your brakes for reasons other than making them look good with bigger wheels, then that means you want performance braking and for Lexus cars, none needed.

ISbb

Me three! haha

SATSONGWIT

My 06 IS250 RWD has stock 205/55/16 tires & wheels. Changing to 20' inch wheels will increase the tire OD by 6%. I have been warned that this could cause brake failure and/or problems with the stability control system. Is this a confirmed problem? How have others compensated for this problem?

lobuxracer

iTrader: (2)

Not really. Bigger brakes will handle repeated stops from higher speeds better than smaller brakes. On a single stop, it is impossible for a bigger brake to stop the car in a shorter distance than a smaller brake unless the smaller brake is incapable of locking the wheel. Tires and available grip make the biggest difference in stopping distance. If you doubt this, try stopping on an icy road sometime. While the example is extreme, it underscores the concept. The big brake comes into its own after you've made repeated stops from high speed and the smaller brake is exhibiting fade. It's hard to fade a modern brake system in a single stop. Anything else is just altering the feel of the system which may or may not be good depending on what the driver likes.

In the real performance world, the car is designed to have the smallest, lightest brakes it can have. Big brakes, particularly big brake discs, are heavier and are unsprung weight. They have greater rotational inertia and force the suspension to be heavier to control the greater mass. It's a bit of a spiral - bigger brakes, heavier suspension (because you need more motion control), less wheel compliance, poorer overall performance, particularly on bumpy surfaces. Those same surfaces that are more likely to bend those big diameter wheels because they have less tire sidewall to absorb the impact.

15951

Bigger wheels can make make acceleration suffer. That alone is reason enough for me to avoid them. I don't see the wheels when I'm in the car, and I'm not concerned with impressing other drivers or attracting attention to myself.

kickin8

iTrader: (1)

that means you'll have a higher chance to pick up a nail in your tire....