I think the real question would be: Is it a good thing?
For asthetics? perhaps. It depends on your taste.
For performance, no. There will be no gain in performance by going to a
10mm wider tire and may actually hurt your performance.
Now, to answer your original question. Can you go wider than the sport
package 225/45-17? In the back, yes, you can fit a 245/40-17. In the
front, no, anything wider than 225 will rub.
If you go wider in the back it's called a "staggered" setup. Many
people do this to their BMWs, in fact M3's are delivered with this
configuration (actually w/ 255 rear rubber). These people think it
makes the car look cool, like a drag racer. However it actually upsets
the handling on the car the suspension of which was designed for the
same width tires front and rear. Putting fat tires on the back will
cause the car to understeer worse than it already does.
But they will look cool.
No one said fat tires are a bad thing.
What people are saying that tire widths are one element of the handling
equation, and must be considered along with suspension characteristics to find
the best handling combination. And that most individuals don't have the
resources to do this better than BMW already has.
FYI, he was specifically asking if he can put wider tires on his OEM rims.
The e46 cars that came with those 245/40/17 tires in the back also came with
wider rear rims (8.5" I believe). If his OEM rims are only 7.5" (and only
he can tell us how wide they really are), then I wouldn't put 245/40/17
tires on them.
I don't know what the back rim width is....I bought this car used, and
it shows up on carfax as a fleet vechicle with sports package (no
aftermarket mods relating to wheels), wrapped in 225 ZR45 17's all the
way around, so I first assumed this was the standard tire
measurements....then reading other postings and forums, I saw some
people mention that this particular car came with staggered set-up,
with 245's in the back.
if the staggered set-up is that bad, why does BMW produce staggered
How do the front tires look compared to the rear ones? If the rears looks
more stretched out than the fronts, then you have wider rims in the back.
If they look identical, then you have the same size rims all around. Also,
wider rims will usually have more lip (the distance between the edge of the
rim and the spoke). 1 inch of extra lip should be quite visible with a
The 325i sport package comes with 225/45ZR17 all around.
The 330i sport package comes with a staggered setup with 245/40R17 rears.
They have different tuning of springs and sway bars, and different wheels.
You can't (shouldn't) put 245 tires on the 8" rims you have (the 330i
has 8.5" rims.) If you do put on a staggered set, you will increase
understeer, unless you change your sway bars.
Sport package in the UK/europe is 18" rims on which they put 255/35 on
the rear and I think they are 8.5" wide.
Many of the M3 folk put 245/40/18 on their 8x18s fronts.
If you want to know what size your wheels and tyres are then go and
read the numbers!
I suppose having LSD increases understeer too so should I fit an open
Understeer is an inherently safer condition than oversteer, or even
neutral steering, which would still allow a driver to generate oversteer
under acceleration. Especially for inept drivers. Remember that half
the owners of BMWs are below average drivers.
The real reason that BMW sells cars with a staggered wheel set-up is
because the people that are buying the cars think it looks cool. It
helps sell more cars. Bling, baby...
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.