I can't remember the pro's or cons when it comes to size of the tire. 17 or 18 are in question.

 

18" tires/wheels look cooler, and perform better in the dry, being summer tire only. On the other hand, they cost more to replace, not to mention lesser durability, somewhat harshe ride and perform less well in the cold. It all boils down to personal preference (I'm getting the 18"). If you are concerned about winter performance of the summer tire in OH, get a set of 16 or 17" steel wheel with winter tires for the cold weather. It's a hassel to change them on your own, though. These big wheel/tire weighs about 50lb--no fun lifting them and trying to line up the nuts and bolts at the same time.

 

I thought I read you can get 18 inch with all season tires in the brochure posted a few weeks back..

 

You can also talk to the people at tirerack.com as they do tire tests.

I run 18's all year round but I also have an SUV for really bad snow days. I like the aggressive stance of the 18's even though they are more prone to road damage. Our roads are bad so I have to drive carefully around the larger pot holes. I've driven 18 inch Michelin and Toyo and 17 inch and I don't really find the ride harsher with the 18's - I think some of that is the tire itself and the suspension.


If I get an IS it will be the 350 with the 18's - I will have the dealer change the tires out to the Michelin UHP All Season which I will run all year.

 

read it again--summer tires only on 18" wheel.

 

If you get the 18's and need to put on a new set of rims/snow tires for the winter (I know that I will), what is the deal with the Tire Pressure Monitoring System? I know that it is able to recognize two sets of tires, but will we all need to add a wireless sensor to each of our snow tire rims? I asked my dealer about this yesterday and they didn't have an answer. He was going to call corporate to try to find out for me. Also, if we do need to buy the sensors for our snow tire rims (or any set of aftermarket rims for that matter), how much does a set of 4 cost?

 

You don't need to question them if you're going to upgrade to 19" wheels.

 

the 18 inch rims, probably actually weigh more than the 17s if they are not forged.


i have 18 inch rims on my car, and you will get more road noise, but slightly more handling grip. i am not sure i could really tell though.

smaller wheels tend to have more rubber, so they may grip a bit more from a standstill. some people say this makes for better acceleration.


the car i have has the same width wheels and a set if 4 pilot sports is something like $900 every 15000 miles.

all seasons would cost about half that for twice or more milage. but they dont make allseasons in my tire size. the selection in 18" is a lot worse than 17" for tires.

 

about getting 18s because of the short lifespan. I will have to see if they offer something other than just summer tires in CA. Otherwise, I'll just stick with the 17s. Do summer tires perform poorly in the rain? I don't really know that much about performance tires, except for that they dont last that long!

 

Regardless if you get 17 or 18" tires...if they're summer tires, they're designed for mostly dry usage. The tire compound and tread design is made for dry weather. You're better off getting an All Season performance tire for the 17s or 18s if you want longer theadwear and obviously comfort. The treadwear for summer tires will be low (180-220 range) so you will get an expected avg life of 15k miles only in real world driving.

 

The Tire pressure sensors are part of the valvestem. The unit itself is in the inner part of the tire/wheel. A set of 4 isn't cheap. It's definitely going to cost you more than $100.00 for a set. I don't recall how much they quoted us during our briefing session with Lexus corp.

 

I want 17s but i wish they had the same design as the 18s.

 

in the same sort of idea, does the 18s give a harsher ride than the 17s? and does the sport suspension give a harsher ride?

i'm thinking of just getting the 17s and perhaps selling them off and replacing them with some GS430 18s.

 

With any lower profile tire/larger wheel combo, the more performance you gain and the more comfort you give up. The stiffer the ride, the least comfortable it will be. That's only a given.

 

i guess the question (which, naturally, can only be answered with a personal test drive) is just how soft the regular suspension is, and how hard the sports suspension is. for example, the regular suspension we have on the old 323i is too soft, whereas the sports suspension we got on our new SLK350 is too hard (though it might just be the short wheelbase's wheel-hop plague on freeways especially)

a test drive it is :/ i'm hoping to save some money by not getting the sports suspension though.