18" all season wheel option vs 19"

[pkarandi]

My local dealer finally has a red gt2 AWD, but it has the 18-inch all season option. I'm trying to figure out if I should care enough to travel or wait for a 19-inch staggered car. A few questions along this line

1) If i get the 18-inch car, and decide a year or two later that I just really want the 19s, can I just find the wheels and slap them on? I don't care about the speed limit at 130, but I do care if the speedo or tpms won't work correctly after the swap

2) Looks. The staggered 19s with the low profile tires look great, but I think from a few feet away I don't notice the difference. The overall diameters of the two are the same right? So the wheel gap should be same for 18-inch and 19-inch?

3) Will the 18-inch wheels help alleviate the common warped-rotor pulsating brake issue?

TIA for any info. Sorry if this has been discussed before, but I couldn't find any dedicated threads, just tangents to other topics

 

[NS_Stinger]

Welcome to the forum here are answers to your questions.
1) Yes
2) Yes
3) No

 

[oddball]

Another viewpoint: I switched from 19" wheels to 18" wheels. The PS4's on 19" wheels have very weak sidewalls. I tore three on potholes. It's a "feature" - the stressed sidewalls can lead to better handling. The ride is smoother on 18" wheels also.
I think 225 is a puny section width, so my 18" setup is 245 on the front and 275 in the back.

 

[pkarandi]

Thanks for the replies NS_Stinger and oddball!

Question 3 about the pulsating brake issue was just wishful thinking... Too bad, 'cause if the 18-inch wheels were immune to this problem, it would have made my decision a lot easier!

oddball, so you switched to the 18-inchers, but went with wider ones? Those are actually wider than the 19's (255 and 225). Is that for additional grip for better launching, better handling, or both? Or mainly for looks?

 

[NS_Stinger]

So I had the pulsing brake issue, I drove with the issue for months and had planned to bring the car into the dealer to have it resolved. I never got around to it and in that time I passed the 1 year warranty mark for brake components. Last week I decided to head out at night and rebed the brakes. I'm now happy to report that the rebedding has removed almost all the pad deposits and the pulsing is now almost gone. I'm thinking a second rebedding would totally solve the issue.

 

[pkarandi]

So I had the pulsing brake issue, I drove with the issue for months and had planned to bring the car into the dealer to have it resolved. I never got around to it and in that time I passed the 1 year warranty mark for brake components. Last week I decided to head out at night and rebed the brakes. I'm now happy to report that the rebedding has removed almost all the pad deposits and the pulsing is now almost gone. I'm thinking a second rebedding would totally solve the issue.

Oh - awesome. Very happy to hear that!

 

[oddball]

oddball, so you switched to the 18-inchers, but went with wider ones? Those are actually wider than the 19's (255 and 225). Is that for additional grip for better launching, better handling, or both? Or mainly for looks?

In my mind, more rubber is almost always better. I have a fair number of mods on the car, so it's got plenty of torque, so getting as much rubber in the back as possible is quite important. It'll still break loose very easily. Getting that much tire in the front can be more of a gamble, so I end up with staggered. I went with 8" rim in front, 9.5" rim in back.
Narrower tires have lower rolling resistance and, to a point, can handle better in turns. A square setup is easier to rotate. My setup now is staggered- and I have directional tires. So each tire will just live where it is and die when it's time.

All just depends on what's most important to you. I enjoy spirited driving and don't mind frequently replacing tires. As noted, our roads are pretty awful, and my personal tastes lean towards 18" wheels for a typical ~26" tall tire. This setup is almost the same as on my '72 Cutlass - just 285's in the rear on a 10" rim there.

As to "re-bedding", be careful. In good cases you'll burn off the old transfer material and deposit a more even layer of new. However, the material that causes pulsing is normally an extremely hard, ceramic-like, deposit that is very firmly bonded with the rotor. Even cutting it off in a lathe can be difficult. So trying to re-bed a pulsing rotor can make it much worse. Granted, at that point, you probably don't have much to loose.

 

[pkarandi]

Thanks very much for the explanation oddball. It's very helpful. I'm going to test drive the GT2 with the 18-inch wheels tomorrow (Wed Aug 7). I shall report back on what I decide to do! The path of least resistance is to go with the 18s, but I will be pissed if I regret it 2 years down the road and decide to buy the the stock 19s (~ $2500 with new tires)