Newbie - Wheel Question

[Nde]

This is could be a silly question. I have an 04 325 with 16" wheels (205/55-16). I'm looking into getting some 17"s (225/45-17 front and 245/40-17, rear).

Do I need to a make an adjustments to my shocks and springs in order to fit my new 17"s? I did the calculator thing I found searching in this forum. It said something about 0.3% slower. Thats great only if I know what it means.

Thanks in advance.

 

[William330]

Make sure when you're done, the overall diameter of the entire wheel
(rim + tire) is the same.

If you get larger rims, you'll need to get low profile tires (which can have
a hard ride), to keep the wheel size the same.

In general, if you change the 'size' of a vehicle's wheels, it will alter the gear
ratio (like changing gears on a 10-speed bicycle), which will impact torque, available
horsepower at the wheels, and throw off the speedometer readout.

This site has some great rims, take a look at what they have for your
model:

http://www.bmwwheels.com/bmwwheels.asp

Good luck.

 

[Nde]

Thanks for the link, that's where I plan on ordering but wasn't sure it will fit my 325. Since I read something here about changing other parts in the car to make it fit. It must be from 16 to 18.

I assume that if I get low profile tires with my 17s, I should be fine without modifying my springs?

Thanks again for clearing things up.

 

[olywamat]

your 205/55-16s are 24.9" in diameter

245/40-17s measure 24.7"

245/35-18s measure 24.8"

These differences are negligible and you will notice no change in speedometer readings (less than 1%). You will, however, notice a harsher ride with the shorter and stiffer side walls. With those 35s and 40s, look out for pot holes, you can break rims pretty easily.

 

[MY2003-330CIC]

I have a 2003 330cic with standard 17s, I put 245-30-19s front and 265-30-19s on the rear
and and I also lowered the front end. The was no adjustment needed. Your car is new enough that the shocks should hold up fine. Also the car still rides pretty smooth with the 19s so your 17s should be fine.

 

[olywamat]

I don't know what you're planning to spend, but you can buy brand new take-offs from the '07 335i with new tires for about $2K. Personally, I think the 5-spoke is an awesome looking wheel. 18"x8 front with 225-40ZR18 and 18"x9 rear with 255-35ZR18

 

[Nde]

I personally really wanted to get 18s but I'm very worry with my shocks and etc. I read something here saying I need to make adjustments which I'm trying to avoid. The 17s I'm paying is the same price as the 18s. All I really want is to be able to slap a new set of wheels with no additional changes. Do you think 18s will fit my 325?

Appreciates the feedback again.

Oh, I have the non-sport 325 04.

 

[Average Jae]

if you + size your rims too much, you might need new brakes due to added wheel weight. smaller pads may get overworked, leading to shorter life + added stopping distance.

+2 rims shouldn't matter too much, since e46s have factory equip up to 18 in non-M machines. but do look into the offsets.

ride will be harsher, even going from my winter 17s with 45 profile, to my 18 summers w/ 40 up fornt, 35 rear profiles, it has gotten harsher. but corners better for obvious reasons.

not sure about the shocks deal. may or may not? but even if you +2, due to lower profile tires, your overall wheel diameter doesn't change much, so i wouldn't worry too much about it.

 

[Kirby]

It's been pretty much said, but to make it concise:

1. Changing wheel size won't cause a problem IF you also change to the correct tire profile to keep the same diameter +/- a few 0.1"

2. Changing wheel size does not dictate that you need to change the suspension as long as you adhere to #1 above.

3. You will have a rougher ride with 18" because the tire has a shorter sidewall, so it is stiffer and has less sidewall material to flex.

4. #3 means that you have a higher risk of damaging the rims.

 

[Nde]

Cool. Thanks all. I will post some pictures once I have them installed. You guys have clear up all my worries. I was worry about the tire bumping into the the walls of the car or if the tire will stick too much. I think I'm going to get the 18s.

Thanks again.

 

[Nde]

As promised, photos of my new wheels. I didn't get the 18s so I got the 17s with Yoko Advan tires. Great wheel and tires.

Thanks again for all the replies.

 

[tazza0712]

Looks great, nice rim. Same as that which came stock on the 330ci I think.

 

[William330]

Looks nice Nde, do you have a "before" photo?

(You can probably eBay the old rims for a nice piece of change as well.)

Keep 'em rolling.