I borrowed this from a Bimmer E46 M3 web site:
The M3 sits on 18-inch M-style alloy wheels (8.0-inch wide front and
9.0-inch wide rear), with appropriately sized high-performance tires (225/45
ZR - 18 front and 255/40 ZR -18 rear).
Will I be able to successfully install this combo on my 330ci? Is there a
reason why it won't fit? i.e. different diff :) larger/smaller wheel wells,
different suspension width? I'm not saying I want to run this combo, but
since I will be buying these wheels and tires via mail-order, getting it
wrong would be expensive. I don't have the luxury of trying out different
sets. I have to get it right the first time. The E46 M3 runs different size
wheels and tires in the front and rear. Is there a reason why doing this on
my car would mess-up my handling and not mess-up the M3 (as another said
I appreciate your indulgence while I get my feet wet with a BMW.
WTF??? How many times are you going to post the same question? You already
got your answers. Don't like what you hear? Is that why you keep asking?
Tell us what answer you WANT to hear, then we'll tell you exactly that and
then you can go away.
With respect, you replied several times to those posts that you didn't get.
And, you copied and pasted the same question several times. Usually, the
verbiage changes when people absent mindedly ask the wame question over and
over because they sit down and type the question from scratch each time.
Your question is identical at least three times, and you replied to two of
them. Now you are replying to the third.
The bottom line is, yes those rims will fit your car. They are an option for
it. That is, the style might not be an option, but the size is, and it's the
size that dictates if they will fit.
If someone would actually help to answer my question instead of lecturing me
on why I shouldn't, the stock sizes, poor ride and such, I would stop asking
the question. My question is simple: What is the widest tire I can put on
the rear of my car without rolling the fenders? That's all. I expect to use
wider rear wheels to accomplish this. 18x9 perhaps. So, has anyone out there
managed to get an 18/275/45 on an '01 330ci? If you have (or haven't because
there was an interference issue), I'd like to hear your story. Why do I want
to do this? I just like the look and I fully expect to end up with a great
handling car. I'm not concerned with a reduction in ride quality as it
couldn't be worse than what I have right now (Sumitomo SU HTR+ 245/40/17.
Very noisy tire). Keep in mind I don't race it. Just spirited, every day
driving. TIA for all of your "useful" answers.
I don't know the answer to your question, exactly. But, I do know you need
to do the math to arrive at the answer.
First, the tire size is always expressed as 275/45x18, where the width is
first, the aspect ratio is second, and the rim size is third. Any other
expression of tire size will just confuse whoever you are talking to.
Second, multiply your CURRENT width by the aspect ratio to arrive at the
size of the side wall, then double this number and add in the rim diameter
to arrive at the overall diameter. Then rework the calculation in the same
way, reducing the aspect ratio and increasing the rim diameter to see if the
tires you want are even remotely close to the diameter of the tires you
have. If the overall diameter is different, the gearing will suffer and the
speedometer will be out of calibration. If you new size is within a few
percent, then you have hit the nail on the head, but if off by more than an
inch, you will feel the difference.
The width of the tires you want will be constrained by the width of the rims
that are available. If you want factory rims, the rear will be capped at
about 18x9 or maybe 19x9. I posted a link to the many different rim options
that you can get through BMW, but I didn't look closely at the list and my
reocllection is that the 3 Series gets an 18 as the largest rim, but I could
be wrong on that. The list gives the tires size that fits the rims, so it
really is a valuable resource for your question.
My car came originally with a 225/55x15 -- I have a '94 with the Sports
Package. I recently changed to a 17' rim because the tires in the equivelent
size are much cheaper, and there are many more choices if I wanted to spend
the same amount of money. The original tire was made by one tire company,
the replacement tires are made by at least a dozen companies. My new tire
size is a 225/45x17, and the diameter went from 25.02 to 25.20 inches. The
difference in the diameter is less than a quarter inch, and just a bit over
a half inch on the circumference, which is what you want to come to.
If you want to move away from BMW rims and go to aftermarket offerings, then
I suggest you look at the BMW options, find what goes on an M3 for the year
of your car, and use that as your guide.
The 275s that you want work out to be just over 11 inches wide. To remain
within the diameter of your stock tires, you are going to need an aspect
ratio of about 30 if you put them on the 18 inch rims. A 275/30x18 will give
you an overall diameter of 24.7 inches. This is very close to stock, and the
speedo and the gearing should tolerate this easily, the big question
remains, will they fit inside the fenders? Personally, I don't think a 275
fits on the stock rims, but that's me. I think you will find your tires
constrained to about a 255/35x18, or maybe a 255/30x18. These will give you
a diameter of 25.25 or 24.19 respectively. One consideration whenthe
sidewalls become very narrow is that the tire's width has to match the width
of the rim. When the sidewalls are very large, then there is more room for
tires that are wider than the rim to accomodate the buldge. When the
sidewalls get very narrow, you really want the tires to be only about a half
inch off of center (an inch overall) wider than the rim. If my math is
correct, a 9 inch wide rim will take a 225 wide tire, observing the rule
that the tires should not be more than about an inch wider than the rim, the
255s would be about as wide as you could go.
Bottom line, I think you will find that you can put a 255/30x18 or 255/35x18
on your car. These should fit fine without rolling the fenders. If you find
a 19 inch rim, then a 265/30 will give you a diameter of 25.4 inches. While
the diameter is a bit large, I think the width will present rubbing issues.
Of course, I am not even considering stagger - different sizes on the front
and rear -- I am only looking at the max size that the rear can take, the
front should take a narrower tire, but you seem to be expecting that. If you
can't do the math, there are several tire size calculators on the 'net that
can help you convert from the size you currently run to a size that you
Here is the BMW Rim Option link that I gave you several weeks ago,
Maybe try calling www.tirerack.com. They've got a lot of factory specs at
hand and have always been a good source of info. Maybe not to buy from them
but at least for the knowledge. Pretty easy to talk to a real person.
The reason they wont fit is because a 330 is not an M3. Im not sure
whether the wheel wells are different or maybe there is an arch on the
M3 or something else. Im not sure as I dont have either one, but what I
do know is that it usually isnt smart to try something if it has
already been suggested that you dont. There is undoubtedly some reason.
If you dont have the luxury of being wrong I would suggest you go with
what is suggested, try DTM Power forum. ask around and see what the
How many times are you going to ask this question?
There is no question on the front wheels, they will definitely fit. They
will fit on all four corners, by the way. The only question is if the rear
wheels will fit, and the question there is if they will fit inside the
fenders. You have no issues with backspacing relative to the M Series wheels
and your 330, but you may have issues with the fenders in the back.
The only other question I have is, why did you tell me this instead of
posting under the OP's question(s)?
The guy that wants to know if the M Series rims will fit is the guy you
should be telling, not me. I told him they would fit, but that he could
verify it by locating his rims and his desired rims in the link that I gave
him, and checking the specs.
The comment was directed to him because he started the thread and to you as
well, as you were wondering, apparently, about the different sizes effecting
handling, etc. I meant no disrespect but I was simply pointing out that
earlier in the thread, or in one of the other threads started by the OP, I
had indicated as such, again.
I just picked your post to reply to the first time, and the second time I
indicated that the tire/wheel combo would fit I was letting you know as it
seemed that you had not seen the previous reply.
I told him they would fit, but that he
And I agree 100%, as I agreed with everything else you told him. Not your
fault, or mine, that he felt the need to post the same question 3 different
FYI, only the 1995 wheels were the same size... 17x7.5, in 96 the
suspension geometry of the M3 was changed "in concert" with the change
in wheel/tire combintaion of 17x7.5(front) and 17x8.5(rear) There is
good reasoning for the extra inch, besides the extra inch or so of
rubber you can stuff. Also, a matched set of 7.5s are far less
expensive than a staggered set.
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