I changed something on my R53 and the difference it made was astounding.

When I bought this car it came with black 18" rims and continental contactextreme 215/35ZR18 tires. It looked pretty sweet but the ride was rough. I happened to have some 15" Racing Hart rims that weigh in around 8lbs each. I knew they would be a bit lighter than the 18's but I wasn't sure how much. The 15's have falken ziex 205/50R15 tires.

When I finally got one of the 18" rims off I was disgusted by how much it weighed. I didn't have a scale but judging with a set of weights I have it was almost 40 POUNDS! My Racing Harts with the tires weigh in around 20.

So I put on the 15's and took her for a spin.
OH...MY...GAWD. WTF? I couldn't believe how different it felt. So smooth. So easy to turn at low speed. And acceleration from a start was ridiculously improved. I expected to feel a slight difference perhaps but this is amazing.
The difference in size between the two wheels (w/ tires) is about 3/4". Soooo my low mini sits even lower now.

I'm selling the 18's to somebody who just cares for looks.

I don't know what the stock wheels weigh but I HIGHLY recommend getting lightweight wheels. I had a big jump down so I guess I noticed a lot more than most people would. 80lbs of unsprung weight lost. That's just golden.

 

I think the white wheels look better than the black anyway.

 

I think that unless you are willing to pay big $$$$ for 2 piece rims, anything bigger than 16's are for looks only on a gen1 with out a big break kit.
IMO the car feels so much better with 16's or even 15's. Performance also seems to be better overall, and so is the ride!!
My regular rims are 16's, and my winters are 15's.

 

The tires on the 15"s are also smaller, by about 3.6%, so acceleration is going to be improved from the size alone. The 15"s sound a bit undersized.

 

Not only that but I bet the wheels look alot better too. I love the 15' rims with the thick tires look. It makes the car look like its a pure track car.

 

As long as you stick to the correct diameter....I have...the 15's can be pretty good...gives the car a playfull feel, I can see why auto-crossers love 15's. They are lighter, cheaper, and CAN look pretty cool...they are great for winter IMO, and the 16's have noticably less sidewall flex, so during the summer they are a great size....

 

The white rims really work with that color combo. Nice!

 

I love the look of it. The only downside is that these tires lower the car about 1.5" because the sidewalls actually flex (unlike the 18" tires).

I've found myself scraping on a lot more things. I actually played street hockey with a plastic 20oz bottle. I think I might trim the piece that keeps scraping.

 

Sounds like you 15's might need to be a bit bigger....bet your spedo is way off now.....but you do have a lot more tourque when starting from a stop!!
All that counts is that you are happy, and the car does look nice!!

 

The correct tire size should be 205/55/15. With your 50's on, your speedometer is reading about 5% too fast.

 

I've always liked a R/W mini with white wheels

 

I wish I could at least get 16's on my R55 JCW, but can't with those Brembo's. So I'll be stuck with 17's if I go that route. Can't go wrong with a lighter wheel!

I love that look too, keep it up!

 

Lighter rims are one of the best performance mods, one that is over looked by most people.

 

Ok, perhaps somebody can answer this for me here so I don't have to start a new thread.

My clearance is TOO LOW! I have about 1.5" of clearance in the front. If I brake hard on smooth pavement I'll hear a good scrape. I was riding to work on a gravel road that is a tad bumpy and I could hear it scrape every now and then. It’s getting pretty aggravating.

The problem is with the bottom piece of the bumper. It is a piece that sticks straight down about 2”+ all the way along. There was another piece behind it that was lower but it broke off from scraping soon after I got the car. My question is will I somehow void my warranty if I remove this 2” piece? I have ext warranty until 2012 and I sure don’t want to lose that over stupid crap. I don’t know how picky they are with things like that. I’m pretty sure it will crack and break off sooner or later.

As you can see the center part of of it has already broken off.

 

For now. I'll be getting 215/50R15 tires next. That should be closer to being correct.

 

A good tire shop will help you get the correct diameter tire, even if you want to go wider as you have. Don't overlook the load range of the tires you buy...they should at least match the oem.
If you scrape during hard breaking, I would have serious worries about potholes and raised manhole covers during construction doing SERIOUS dammage......or totaling your car. Watch out and be careful till you get the new tires!!!!

 

Hey Welcha I noticed some red on the front, are those JCW brakes fitted over those RH wheels? If so let us/me know which RH models wheels they are. I know Motegi TrakLites 15's fit over JCW brakes but they are hard to find now. They look sweet Mine scrape with 18s, I'm gonna be dragging with 15s.

 

I don't think they are JCW brakes. I believe they are just painted red. (the red paint is coming off in some areas)
But the wheels are CP-035.

I'm going to try to mess with the bumper on Friday and get that lower piece off or at least out of the way. I noticed I can push up on it and raise it a few inches. Perhaps I can strap it up from underneath and avoid scraping on bumpy roads.

 

15's are the ticket!! Especially with the gearing in the 05-06 models years. I never understood (other than possibly looks) going to big wheels. Unless they are super light or bbk, there is no real advantage.

I scrape that little lip under the car sometimes, you will become aware of situations where it may scrape and try to avoid best you can. The part is easily replaceable.

 

Yes, that is much closer to correct than what you've got now, only about 2% off.

http://www.miata.net/garage/tirecalc.html

 

Not the part I'm scraping. It's a molded piece of the bumper. You can see it in the picture. I think something is disconnected under there. I need to jack it up and take a look. I need to get a low-profile floor jack.

 

CP-035!!! Oh goodness these might be even harder to find than TrakLites 2's in 15, RH CP-035 are super lightweight wheels too
I believe your JCW lip sits lower than the normal MCS front bumper's lip, so does the GP bumper, I even scrap that lower lip with 18 inch wheels on EVERY driveway. Maybe lifting the car and dremeling the lower lip.

 

Why don't you get yourself a nice set of coilovers and just raise your ride height a bit! You like your car now, imagine what a good suspension setup would feel like!!

 

Nice ride! What kind of 18's did you have? Got a picture? Price? Location? Shoot me a PM.

 

Your missing some parts on that lower aero kit friend.....your better off just putting on the correct size tire for proper ground clearance. Also, right now you are racking up more about 5% more mileage than actually travelled so you will reach oil changing mileage before it's time to do so.....

Tire size chart: http://www.miata.net/garage/tirecalc.html will help you see what I am referring to.

You are missing 4 plugs that go into those holes on the bottom as well as the two side support wings they are attach to...

Part No 26 in this schematic and 4 plugs listed as part no 17 in grid boxes to right of car....