My Dad is looking into buying a new M3 and is wondering how much the forged 19's weigh? Also, how much do the stock 18's weigh in comparison? $1700 seems like a good deal for a set of 19's. Do you guys think it is worth it?

same weight as the 18s... i think around 24lbs?

I think it is every bit worth the money. The 19s are so nicely designed that they are making the 18s obsolete. If your dad is really interested in lightweight wheels, then get the 19s for street "pimpin" and buy a set of SSR Comps for the track.

Originally posted by JaWeb
I think it is every bit worth the money. The 19s are so nicely designed that they are making the 18s obsolete. If your dad is really interested in lightweight wheels, then get the 19s for street "pimpin" and buy a set of SSR Comps for the track.

Hehe, that's what I told him to do, great minds think alike:devillook

Thanks for the info guys.:)

Actually, the E46 M3 18s look super pimp on the 5series. I saw a set the other day and thought about putting them on my 5series.

The OEM 19s weigh a half pound more each, the 19" tires are a bit heavier too.

The OEM 18s look much better in my opinion but they are in fact not as strong as the 19s nor as easy to repair rash on.

Brian

I got the 18's. I think the 18's give the car a more aggressive look. Plus for racing there better. (specially if you have the 275/35 wheels in the back)

Spotted this on roadfly.

This magazine states that "there's no doubt that the drivers wheel of choice is the 18s. The 19 corrupts the chassis response, dulling its reactions and actually reducing grip on uneven B roads to the extent that even the more flexible cab on 18s is superior to a 19 in-shod Coupe."

Posted by varsitydramat .

http://webdrive.service.emory.edu/users/nkhalid/evo.jpg

http://webdrive.service.emory.edu/users/nkhalid/evo%202.jpg

Brian

19" front OEM wheel is 27,70 lbs
19" rear OEM wheel is 29,20 lbs

So 19" wheels are 11 lbs heavier than 18" wheels in total.
If you consider that it is unsprung weight, 11 lbs should be noticable.

Brian, its funny that their only expense is for two tires. :rofl:

Is that CAR or EVO?

Originally posted by ///MDriver
Brian, its funny that their only expense is for two tires. :rofl:

Is that CAR or EVO?

Thats very coincidental :biglaughb I didn't even catch that until you pointed it out.

I believe the article is from EVO.

Brian

Yes, that is EVO. I just dug out that issue to read the article.

If the 19s are so bad, why put them on the CSL?

The M3 CSL 19" rims are totally different from the regular E46 M3 19" rims both in design, strength, and weight

Also the M3 CSL has 18" rotors which I assume must need a 19" wheel for clearance.

Brian

The original CSL came with the current production E46 M3 19s... which were later changed to the designs they are using now.

If memory serves me correctly the rotors on the CSL are only slightly bigger than the standard production E46 M3 rotors... not enough to require a 19" wheel.

Here we go...

standard E46 M3 rotors, 325mm
CSL E46 M3 rotors, 345mm

Originally posted by dallasbboy
The M3 CSL 19" rims are totally different from the regular E46 M3 19" rims both in design, strength, and weight

Also the M3 CSL has 18" rotors which I assume must need a 19" wheel for clearance.

Brian

The CSL front rotors are the same size as an m5 13.6", plus an 18" rotor would require a rim much larger than 19".

Looks like the concept M3 CSL has 18 inch rotors and OEM M3 19" wheels.

http://www.edmunds.com/news/conceptcarspotlight/articles/48106/article.html

Brian

It's gotta be a typo... the numbers I quoted above are from the BMW press packet for the CSL. Plus 18" rotors won't fit. A 15" rotor/caliper setup barely fits behind a 19" wheel.

Originally posted by dallasbboy
The M3 CSL 19" rims are totally different from the regular E46 M3 19" rims both in design, strength, and weight

Also the M3 CSL has 18" rotors which I assume must need a 19" wheel for clearance.

Brian

18" rotors? Really? That would mean the rotor rubs the inside of the rim?

Not to mention the size of the caliper that is hanging on the rotor. Like Kev said, its gotta be a typo.

maybe 15"?

Originally posted by raffaelli
maybe 15"?

as I posted above ( http://www.bimmerforums.com/forum/showthread.php?postid=1249399#post1249399 )...

standard E46 M3 rotors, 325mm
CSL E46 M3 rotors, 345mm

325 millimeters roughly equates to 12.7 inches
345 millimeters roughly equates to 13.5 inches

Originally posted by dallasbboy
Spotted this on roadfly.

This magazine states that "there's no doubt that the drivers wheel of choice is the 18s. The 19 corrupts the chassis response, dulling its reactions and actually reducing grip on uneven B roads to the extent that even the more flexible cab on 18s is superior to a 19 in-shod Coupe."

Posted by varsitydramat .

Brian

not to hijack this thread, but it's interesting that the only magazines I've seen that prefer 18s over 19s are UK-based. It seems that every M3 comparo stateside is done with 18s. Maybe BMW offers the 19s for the bling factor, like how the new 760 has 20s even though it rides worse than a 745 on 19s or 18s...

My car has 18s, but it's not that big of a deal for me, and I'm glad I saved the bucks by not getting 19s. that dough goes toward SSR Comps for the track! :)

Originally posted by pride355

If you consider that it is unsprung weight, 11 lbs should be noticable.

You're on crack.

The total unsprung weight is close to 250lbs (rotors, wheels, tires)

11lbs is around 3% increase in unsprung weight.

You won't feel a difference. IIRC, the 19's are wider, and thus on the second set of tires you could fit wider and better tires (read: SO-3's).

Originally posted by b0rf
You're on crack.

The total unsprung weight is close to 250lbs (rotors, wheels, tires)

11lbs is around 3% increase in unsprung weight.

You won't feel a difference. IIRC, the 19's are wider, and thus on the second set of tires you could fit wider and better tires (read: SO-3's).

Actually I've heard that 1 pound reduced unsprung is 10 reduced sprung elsewhere so 11 pounds is actually 110!

Brian

Originally posted by Kevlar
If the 19s are so bad, why put them on the CSL?

The only BMW comment I have heard on this decision was that the 19" wheels helped with "high speed stability". I think we'll all agree it's not helping off the line acceleration and slightly increasing unsprung weight.

Since the CSL is still governed to 155mph (apparently the CSL was bouncing off the speed limiter at the Nurburgring on the long straight), this doesn't seem to make that much sense. I would think 18" wheels are more than enough for 155 mph (note Mclaren F1 came stock with 17" wheels, not sure if that's even a meaningful comparison).... maybe it was just to get more rubber on the road in the high speed sweepers at the sacrifice of some low-speed handling and agility.

Anyways, I'm confused... I'd love to get BMW's official explanation for this, if I thought they'd tell me the truth :). If only the 18's were forged and lighter :)...

- John

Originally posted by dallasbboy
Actually I've heard that 1 pound reduced unsprung is 10 reduced sprung elsewhere so 11 pounds is actually 110!

Brian

I've heard that too... but I believe the numbers are varied. I think it's for every 1 pound of unsprung weight is equivalent to 3 or 4 in the center of the car.

Of course wheel rotational mass varies as to where the weight of the wheel resides (closer to the center or outside of the rim)

hmmm the uncertainty continues...

"Riding on specially developed 19-inch light alloy wheels with a new design of sports tyres, the CSL employs 18-inch brakes for supreme stopping power. "

http://www.bmw.com.au/M3CSL/

Brian

Originally posted by dallasbboy
hmmm the uncertainty continues...

"Riding on specially developed 19-inch light alloy wheels with a new design of sports tyres, the CSL employs 18-inch brakes for supreme stopping power. "

http://www.bmw.com.au/M3CSL/

Brian

dude... there's no uncertainty. the csl brakes are *definitely*13.5 inches. think about it...

18" brakes are so beyond ridiculously large i don't even know how to fathom them being attached to a passenger car. you'd need like a 24" wheel to fit brakes like that. (can you actually picture an 18" rotor?? it would probably weigh about 50-75 lbs...)

i think the very largest aftermarket BBK i've seen is perhaps Brembo's 14" rotor kit... maybe something in the 14-15 inch range exists, but i really can't see the point.

- John

Originally posted by dallasbboy
Actually I've heard that 1 pound reduced unsprung is 10 reduced sprung elsewhere so 11 pounds is actually 110!

Brian

So you're saying if I had 500lbs of unsprung weight and reduced it to 300 my car would "weigh" 1000lbs?

No.

There is no correlation between unsprung and sprung weight. It's all relative-- if you have 300lbs of unsprung weight, and reduce 11lbs of that, you won't feel anything.

Look at the big picture.

Originally posted by b0rf
So you're saying if I had 500lbs of unsprung weight and reduced it to 300 my car would "weigh" 1000lbs?

No.

There is no correlation between unsprung and sprung weight. It's all relative-- if you have 300lbs of unsprung weight, and reduce 11lbs of that, you won't feel anything.

Look at the big picture.

Theres a limited amount of unsprung weight (wheels, tires, suspension control arms, etc) No more than 300 pounds I would estimate on any given car.

If you reduce your unsprung weight relative to stock even by a few pounds you will be able to tell the difference. How to quantify this is not clear as it depends on the rim design as Kevlar pointed out but its still there.

The unsprung to sprung weight ratio does exist it just will be different depending on the individuals setup.

Heres a post on roadfly about it.
http://bimmer.roadfly.org/bmw/forums/e46m3/forum.php?postid=3770890&page=1

Brian

<The unsprung to sprung weight ratio does exist it just will be different depending on the individuals setup.>

The only way to determine such a ratio would be through performance testing. It's difficult to find a direct correlation between weight and acceleration testing especially since time is involved.

Also-- 2lbs reduced from the outside of the flywheel will show more gains than 2lbs reduced from the inner part (closest to the center/axis) of the flywheel. Same with wheels, tires, and/or rotors. Thus, not all unsprung weight requires the same force to move. i.e. 10lbs on the outer most part of the wheel would be harder to push than on the inner most part.

Too many variables to make a ratio.

Also, post #31 was totally theoretical and only to make a point.

Originally posted by John H
The only BMW comment I have heard on this decision was that the 19" wheels helped with "high speed stability". I think we'll all agree it's not helping off the line acceleration and slightly increasing unsprung weight.

- John

Actually, CSL's lightweight wheels are lighter than OEM 18" wheels.

Also 18" brake rotors, you read all over the press, is a typo. CSL has 345 mm front rotors which is about 13,5".

As for feeling the difference of 11lbs less unsprung weight, it depends on the driver.
I admit that it is hard to feel since 11 lbs is not a big deal. However, especially at low speed turns and low speed slaloms, and at auto-x an advanced driver should notice the difference. So actually I'm not on a crack...

John,
I do wish to have forged and lighter 18" OEM wheels, as I had on my E36 M3 EVO.

Originally posted by pride355
19" front OEM wheel is 27,70 lbs
19" rear OEM wheel is 29,20 lbs

So 19" wheels are 11 lbs heavier than 18" wheels in total.
If you consider that it is unsprung weight, 11 lbs should be noticable. Not according to Bekkers.

They say the cast aluminum 18" front wheel (8"x18") weighs 26.4lbs ( http://www.bekkers.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=BI&Category_Code=borims18m3 ), while the forged aluminum 19" front wheel (8"x19") weighs 26.9lbs ( http://www.bekkers.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=BI&Category_Code=borims19em3 ). This, by the way, makes perfect sense since the 19" is forged instead of cast, and it also foots with individial weight comparisons I've seen.

So, assuming the 19" wheels are an average of 2% heavier (maximum--roughly 1lb total front and 1.5lbs rear), you're only looking at ~2.5lbs maximum additional unsprung weight by opting for the 19" forged rims; a negligible increase. For this to make a significant acceleration or handling difference is impossible.

It comes down to personal preference. . .

-j

Originally posted by jim m
Not according to Bekkers.

They say the cast aluminum 18" front wheel (8"x18") weighs 26.4lbs ( http://www.bekkers.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=BI&Category_Code=borims18m3 ), while the forged aluminum 19" front wheel (8"x19") weighs 26.9lbs ( http://www.bekkers.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=BI&Category_Code=borims19em3 ). This, by the way, makes perfect sense since the 19" is forged instead of cast, and it also foots with individial weight comparisons I've seen.

-j

I haven't weighted them myself.
The data is taken from ETK..

Originally posted by GabbyGM3
I got the 18's. I think the 18's give the car a more aggressive look. Plus for racing there better. (specially if you have the 275/35 wheels in the back)

Only bacause it has a lip. . .

I personally like the 19"s more.

Originally posted by John H

Since the CSL is still governed to 155mph (apparently the CSL was bouncing off the speed limiter at the Nurburgring on the long straight), this doesn't seem to make that much sense. I would think 18" wheels are more than enough for 155 mph (note Mclaren F1 came stock with 17" wheels, not sure if that's even a meaningful comparison).... maybe it was just to get more rubber on the road in the high speed sweepers at the sacrifice of some low-speed handling and agility.

- John

Well if you take that into account, a real F1 car only has 13" wheels.

.... and weighs 1200 lbs, uses "hand of God" really wide tires, has state of the art aerodynamics.

not really sure you're comparing apples to apples there....

- john

Personally I love the 19's they look soo much better to me. I use my 18's for autocross now and can't stand the way they look, after having the 19 on. Makes the car look less aggressive (the 18's) to me plus they are harder to clean..
I also dynod my car with the 18 vs. the 19 and saw no difference but I'm not sure that would matter as far as sprung and unsprung weight goes. But as far as putting the 19's back on after a race I can't the difference at all other then the car seems a little stiffer and more stable at higher speeds. That’s just my two cents. :dunno

Originally posted by jim m
Not according to Bekkers.

They say the cast aluminum 18" front wheel (8"x18") weighs 26.4lbs ( http://www.bekkers.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=BI&Category_Code=borims18m3 ), while the forged aluminum 19" front wheel (8"x19") weighs 26.9lbs ( http://www.bekkers.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=BI&Category_Code=borims19em3 ). This, by the way, makes perfect sense since the 19" is forged instead of cast, and it also foots with individial weight comparisons I've seen.

So, assuming the 19" wheels are an average of 2% heavier (maximum--roughly 1lb total front and 1.5lbs rear), you're only looking at ~2.5lbs maximum additional unsprung weight by opting for the 19" forged rims; a negligible increase. For this to make a significant acceleration or handling difference is impossible.

It comes down to personal preference. . .

-j

I weighted mine on a bathroom scale and couldn't see a difference between the two it's such a slight difference I think that is why I don't notice driving ether. :az:

why would you expect a difference on the dyno from changing your wheels?

- John

Originally posted by John H
why would you expect a difference on the dyno from changing your wheels?

- John
I read it on E46 Fanatics, but didn't belive it so I had the 18's on the first time when I went to dyno (before i owned the 19's), then the second time i had just put the 19's on and had a free run, so more for just for me.. No real reason