Redfearn

I have a 2006 IS350 with the 18" wheel package and the 225/40R18 Front and 255/40R18 Rear Summer tires. (Apparently all 350's in Southern California are delivered with the 18" wheel package - a "mandatory option".) I do not have the sport option. The only thing I don't like about this car is how hard it rides - the city streets I drive are lousy, and the stiff ride is not pleasant. (It's fine on the freeway.) The IS300 I used to own was, in my opinion, a much better compromise on ride vs. handling. Would I get any improvement in ride if I pulled the 18" wheels and tires and replaced them with aftermarket 17" wheels and tires? Any recommendations on tires that would support the power and speed of the IS350 and give me a better ride? (If my car rides hard, I can't imagine what the sport suspension would be like.) I know this change goes against the flow for owners in this board, but I do so much city driving that I would like to see if I can improve my daily commute.

Thanks.....David

DonJuan45i

yea, there would be a difference due to the tires. If you get 17's put on, you will have a tire with a bigger sidewall, that will absorb a lot more of your bumps and other road imperfections. As the 18's and any larger rim, will have to come with smaller tires more low profile tires, that get smaller as you go up in diameter, and transfer a lot more of the bounce to your ride, rather than absorbing it. You could experiment with different tire brands, and types. Some tires are noisier than others, But definately moving to 17's should give you a more cushioned ride. Im sure you would have no prob trading your 18's for 17's+cash.

viettho

iTrader: (1)

yeah,but I rather keep my 18" wheels. they looks much better that way.

ISbb

I have no chance since the gov law here in Macau only allows stock size rims... So that I could put a 17inch wheels to my IS only... I think the 17inch ride is good and comfortable, I really like to get a 18inch set of wheels when my 17inch tires use out no matter it is legal or not...

ff_

Apples to apples, if you go with 17" wheels instead of 18", you're only gaining 1/2" in effective sidewall height. It'll help, but probably not as much as you're expecting. What's going to help you is switching from a summer tire to an all-season tire. All-season tires tend to have much softer/flimsy sidewalls, which absorb bumps much more softly. But, as you probably know, you're sacrificing much of the handling ability the car does have.

I'm curious, how can people find the 18" wheel option on the IS too firm?What car are you coming from?

viettho

iTrader: (1)

not at all for me, I love the 18" wheels, great ride, look nice!

omgitsroy

iTrader: (1)

i think it's a crap load better than my alltrac....

if you're not happy you guys should get a ES or GS instead of the IS

Redfearn

Well, I traded in a ES330, which is of course much softer. However, I was comparing the ride in the IS350 to IS300 I used to own. It was a much better compromise - much better ride and still very good handling.

austinw356

ughh that sucks, well that kinda sounds like the proposed "no baggy pants" law from Dallas.

Ichigo

Your best bet might be trying to find someone who has swapped out their stock 17's off of a 2IS. I think it will be cheaper than buying aftermarket 17's. I got the 17's on my IS350 bc i planned on getting aftermarket rims and felt there was no reason to pay extra for the 18's.

socalJD

Before throwing money at new rims/tires, try some simple fixes like taking 4-5 psi out of your tires (30 fr, 32 r) and finding alternate routes with better roads. I purposely avoid streets with railroad tracks or numerous potholes (I work in downtown LA). Worst case, try to get the OEM 17" staggered rims, since those should be cheaper than aftermarket and are hubcentric and maintains the OEM outside wheel diameter.