Hey I just migrated from an 04 to an 05 (thanks to a deer) coupe that came stock with the 19" rims and the metal holed gas pedals and orange stitched wheel (Is this considered a feature who cares what color the stitching is I guess it does look a lil cooler tho now typing about it). I am assuming this means I have sport suspension. To be honest I would have actually preferred the stock suspension as I like the ride quality better. So I am thinking of going to 18" rims to smooth out the ride some. I went on some site and it said by doing this when my odometer reads 60mph I will actually be going 59.7 or something. Is there any other negatives of this rim size modification to the sports suspension?

Also while I am on here any thoughts on the $60 K&N re-usable air filter vs the stock paper one? NOT referring to cold air. Just the normal rectangle style. Thanks for any thoughts.

Also would anyone want to purchase my set of 19's? NYc area

 

Dude...keep the 19's...they look better... K/N drop in is totally worth the $....

 

I actually think the 18's looks nicer and simpler and better on diamond graphite. I like the 19's on darker colored blacks and dark blue. Also I want to have a smoother ride, my conti DWS 225/45/18 are smooth. If I got them in 19;s they would have a 40 aspect ratio and would not be as smooth. Any additional info on why the kN filter is worth the money? Does it really add any power? Sound? Gas mile?

 

Tires in 18" size are generally cheaper...I prefer the look of stock 18's also but I'm biased (DG w/ 18's). The ride quality is dependent on tire type (summer vs. all season etc) and other factors...not just aspect ratio but generally speaking you probably wont regret going back to 18's

 

Well, it's all about what you like... I have a DG also... upgraded from 18x8's to the staggered 19 rays which
Are 8.5 in the rear for better handling... The K/N will breath better and sound a little better.. also yielding about 1-2 MPG more...

 

Yea I got a practically brand new set of conti DWS 225/45/18 all seasons mounted from my old g35 ready to rock. I liked the ride with them. Right now I got 245/40/19 on all 4. Do not ask me why the dude before me chose this and did not get staggered, but the ride sucks. Also your point is correct these are summer sport tires so yea the ride is not supposed to be as smooth.

 

Stay with the 19s and buy the correct tire sizes

 

I hate to even answer this question...but here goes...the k&n is a great replacement to the oem filter. Unless were talking about replacing a worn oem filter, then you won't gain any noticeable hp, gas mileage, and definitely not sound, with a k&n. Throttle response will increase with a new filter oem or k&n. Either way the K&N has slightly better flow, and is reusable.

If you want to down(grade)size your wheels, then go for it. However you will lose handling with a narrower tire, and you need to read up on aspect ratio. "40" is an aspect ratio, NOT the height of the tire wall. For instance, a 45, depending on width, can be "shorter" than a 40.

If the ride quality is bad, then you may want to look at suspension and control arm parts, before changing the wheels, which is like putting a band aid on an open wound,

 

The most important thing is keeping the total diameter pretty similar. I think most people recommend within 3% difference at most. When it gets too different you may get problems with the abs and vdc. The 225/45/18 are close to 3% smaller, and with normal tire wear will probably go over the 3% limit. If you downsize to the 18" wheels, you probably would want to get taller tires, like a 245/45/18 or 225/50/18 is basically the same size as a 245/40/19. Also, not all tires are the manufactured to the same size, even if they have the same sizing numbers, so I would try to get tires that are supposed to be nearly equal in size.

As someone said, the second number, the aspect ratio, is the height of the sidewall as a percentage of the track width.

If you keep the outside diameter the same, dowsizing to 18" will probably actually get you better performance in nearly every way, due to the significantly less unsprung weight. Getting a narrower track tire though (225 as opposed to 245), gives you a smaller contact patch and less traction in the dry, but better gas mileage.

 

Not really. OEM Ray's weigh 20/21lbs, the OEM 18's weigh 24lbs. The 19's are forged and lightweight. OP you can always buy the stock suspension, I'm sure someone will sell it to you for cheap. I'd imagine the suspension is more of a problem than the tire size.

 

Well the thing is that I don't want to make a huge project of this. I just figured that since 2 of the 19" low profile sport wheels are already worn down badly and have serious rust I am looking at doing some work to 2 rims and replacing all 4 tires since I prefer to use 1 set of all seasons year round. With that said I have pretty much brand new pair of 225/45/18 Conti DWS mounted on immaculate 18" rims sitting in my shed. So instead of repairing the 19's figured I would just buy another pair of 18's and mount them with brand new 245/45/18 for the rear (same exact setup as my 04 coupe). This should alleviate road noise and the rougher ride to some degree I am thinking. I most likely wont touch the suspension unless I have to. Whatever ride quality improvement I get from the new tires would be fine. But figured I would post here first before I altered the stock config. I am glad because good points were tossed around, maybe I look at getting 255/45/18 ?

 

255/45's will make for a sloppier ride. 255/40 or 255/35 are much better suited

 

I'd keep it simple and stick with 225/45 front 245/45 rear on your 18's...immaculate 18's trump curb rashed and rusted 19's any day of the week.

 

Yea I am leaning in that direction since it doesnt seem like a HUGE no no to do this. Also I edited my other post there is no real rashing on those 2 rims, they just have some SERIOUS rust caked in the corners. Enough that would need a re-paint once rust was sanded or wired off.

 

I dislike the thought of anyone down grading their coupes. Sell your 18s with those 225s and have your 19s P/C a color you like, ride quality between the sizes isn't that different. Nothing wrong with running 245s on all four corners, better handling and traction....Gary