I would like to replace my 1998 BMW 540 (which I love) with an IS350 but I am concerned about the wheel sizes.

In Boston, we are loaded with potholes. I imagine the IS350 18" will not last for even a month before they are bent, with the way I drive and the roads I drive on. And for Lexus who invented smoooth, isn't the ride a bit punishing, again over the potholes? There is just not enough rubber there to absorb routine pothole driving. And what about the tire wear; the IS brochure says not to expect more than 15,000 miles.

The 17" wheels do not seem much better. At 20,000 miles.

Is it only about the looks of the low aspect ratio sidewalls or is it handling on the rare smooth street?

I know the IS is the BMW beater. And I like a car that is geared towards handling. The IS350 seems to be the closest to my 540. That is not as weird as it first seems.

If the answer is to baby the IS350, I am no longer interested in it. I don't want to baby it; I want to drive it hard!

I know, this forum is for Lexus owners. I also have an ES300.

 

not sure but 16's might not clear the brakes?

 

How much sidewall is enough?

If you went with 235/45/17"s you'd have 4.16" of sidewall. Any smaller than that and you might have some clearance issues with the brakes.

 

I would think 17" would be enough . . . i know there may be potholes, etc but there should be a 17"/tire combo that fits your needs . . . (large sidewall)

 

I got 17's with my IS350 and have had no problems with the potholes in socal. I figured at some point im going to switch to some 19' rims and didnt want to pay the extra $$$ for 18's.

 

My IS250 will come with 16" wheels, I m sure none of us would like to be seen with 16" wheels. Also I m sure the 16" won't fit the IS350 Calipers.

Matt =)

 

that 15k miles is underestimated and highly dependant on make/model of the tire. You can find higher performing tires out there that will easily last 20k. Im guessing the disclaimer is just there to scare some people off so theres no surprises

 

I live in RI and work in Boston - driving back and forth each day, and the potholes are truly unbelievable - some that span the entire lane of a highway/street, and as deep as a friggen moon crater. maybe you should opt for the wheel/tire coverage? i bought this thru the dealership... it's a one time cost of $500, and they will replace tires/rims if damage is done to them. well worth the $$$ in my opinion if you live in a place like new england.

 

I've heard of many tie rod replacement/repairs due to the off-road streets of Boston. And the recent
rains made it worse, it just hides them. I don't know how lowered cars make it by.

 

17" wheel/tire should be ok (16" may not clear the 350's larger brakes). The tire wear has more to do with the specific summer tires, rather than the size of the wheel. Just stick to all-season tires with higher wear index.

 

How did you manage to get 17's with an IS? I thought all IS250/350's in California came with 18" summer tires! I've got 18's and want to see if 17's give a softer ride. You wanna trade?

 

Consider forged wheel. They are extremely strong and lightwieght, Although pretty expensive

 

I am sure u could use a 16" wheel, just make sure if its a IS 350, you make sure they can clear the brakes.

A lot of it is not just for handling but AESTHETICS. The 2IS has very tall doors with short windows, bigger wheels help the cars looks a lot. Also looking at the competiton, 17" wheels are becoming more and more standard.

Another trick car makers are doing that Lexus has not followed, is larger tires with larger wheels. For instance, Lexus has always used true low profile tires. Take the G35 or Acura Tl for example, they are large pigs in size for their class and thus they can fit 17 and 18 inch wheels and tires with a larger sidewall.
IS with 18s has a 40 I think sidewall
G35 has 18s with a 45 sidewall or maybe even a 50.

 

OK so:
1. 16" wheels won't clear the larger 350 brakes. Make sense.
2. 17" should have sufficient sidewalls. I don't know.
3. Its all season tires, forget the summer tires. I hate changing over.
4. and it is all about the looks only. I may be too practical for the IS350.

One remaining question is: why does the brochure warn of 15,000/20,000 miles on 18"/17" wheels. You can't say they didn't warn you.

My 540i has gotten 40,000+ miles each on two sets of all season 16" regular profile Conti Contact factory tires. I bought the car with 36,000 miles and it came with 4 bent original wheels and I bent 4 replacement wheels from Tire Rack. I attribute the bent wheels to potholes, hard driving and the sidewalls. If I go with the 17" all season IS350 , I will still have pothoes, hard driving and lower than current profile tires. I still don't know.

I can give up the Ultimate Driving Machine but I am not sure I can go with the IS because of wheels even though it is such a kick to drive. How strange is that?

Thanks everone.

 

16" wheels and tires will clear the big brakes, you just have to buy some aftermarket ones with the right offset.

Remember, the IS is the sporty sedan, so Lexus will offer the 17s and 18s. Even the ES now has 17" wheels standard, however, since its a much larger car, it has thicker sidewalls.

I've driven 540s with the 16s and 17s and the ride was cushier with the 16s but much sportier with the 17s (and the accompaying sports pack)

Good luck!