18" or 19" Wheel Decision Dilema! - The Unofficial BMW M5 Messageboard (m5board.com)

heykman · 18th February 2007, 06:37

So the Dinan Stage 3 JRZ suspension should be here in the next couple of weeks and I would like to have my wheels and tires in place before I take it to Dinan. So hears the thing, I have exhausted myself with searches on different setups and my other half is telling me "make a decision already you spend way to much time on that board". Can't believe how addicting this place is!

So with that said here are some of my thoughts on what options I am considering along with questions. Someone please talk some sense into me and set me straight! Forgive me if I am not concise and if this sounds scatter brained...

Personally I think a 19" wheel looks better on the E39 than an 18", however is there a real big performance difference between an 18" and a 19" wheel? And when I say difference I'm talking in terms of ride comfort sacrificed by the difference in profile? Handling? Spool up? Keep in mind that I do very "spirited driving" as I live in the Santa Cruz mountains (people in the SF Bay Area know about Hwy 9) however, I doubt if I will see the track. Is there enough performance difference to really matter?

I was thinking of running OEM rears on all fours with Michelin PS 2's 275/35's. So much so that I have already purchased the spacers and wheel lugs. I like the look of the OEMs and I think this would be a neutrally balanced set up. But those 19"s...

Dinan on all four corners with the same tire configuration. Man those things are light! Not crazy about the finish with a Carbon Black car but I could always have them painted. But those 19's...

Now the BBS RG-R, love that Diamond Black finish and I think that would look great on Carbon Black. What? They don't come in 9.5" width's? Ahhhhh!!! The RS-GT's do!....but I don't like the lighter finish and not crazy about the exposed fasteners. What? They come in 19's?! But wait a minute what about that performance thing?

So let me throw out these scenarios with the BBS and someone let me know if they will work or if I am dreaming...

Option 1: BBS RG-R 19" x 10" 275/30's on all four corners.

Option 2: BBS RG-R 19" x 10" 275/30 front 285/30 rear.

Option 3: BBS RG-R 19" x 9" 275/30 front 19" x 10" 285/30 rear.

And no, I am not considering the 18's in BBS because I would just assume keep my OEM's or go with the Dinan's if that were the case. If one of these options will work and performance won't be that great of an issue, I just might get me some 19" BBS RG-R's

I applaude anyone and everyone who stumbled through this ramble

Need4Spd · 18th February 2007, 08:46

I'm biased in favor of retaining a reasonable ride on a street-driven car, so I would suggest staying with the OEM 18s and run 9.5s all around with 275s. I know others who will differ on this, but to me, an M5 is instantly recognizable in part by its distinctive wheels. Anyone can buy aftermarket wheels and slap them on a 540 or even a 6 cyl e39. With a stage 3 JRZ Dinan suspension, your car will handle Hwy 9 and 17 with ease and will still ride great, and anyone who matters will know it's a real M5.

Archille · 18th February 2007, 08:54

The OEM wheels weight a ton, each. Highly recommend the 19" RG-Rs but I am biased...

Laidback · 18th February 2007, 09:33

I have seen David's car in person with the RGR's and they look awesome...and the drop on his car is just right

check this video theres a close up shot on David's car on the first 20-30 seconds...

http://www.wildyoats.com/Videos/M5VegasTrip0107.wmv

aw/ir02smg · 18th February 2007, 09:45

heykman,

well you picked one of the lightest 19s around. good looking too...

i have a pic of archille's awesome m5 on 19 inch rgrs. this is the post - sorry- it's about halfway down. you wont miss it.

http://www.m5board.com/vbulletin/sho...&postcount=712

DRM · 18th February 2007, 10:05

Quote:

Originally Posted by heykman

So the Dinan Stage 3 JRZ suspension should be here in the next couple of weeks and I would like to have my wheels and tires in place before I take it to Dinan. So hears the thing, I have exhausted myself with searches on different setups and my other half is telling me "make a decision already you spend way to much time on that board". Can't believe how addicting this place is!

So with that said here are some of my thoughts on what options I am considering along with questions. Someone please talk some sense into me and set me straight! Forgive me if I am not concise and if this sounds scatter brained...

Personally I think a 19" wheel looks better on the E39 than an 18", however is there a real big performance difference between an 18" and a 19" wheel? And when I say difference I'm talking in terms of ride comfort sacrificed by the difference in profile? Handling? Spool up? Keep in mind that I do very "spirited driving" as I live in the Santa Cruz mountains (people in the SF Bay Area know about Hwy 9) however, I doubt if I will see the track. Is there enough performance difference to really matter?

I was thinking of running OEM rears on all fours with Michelin PS 2's 275/35's. So much so that I have already purchased the spacers and wheel lugs. I like the look of the OEMs and I think this would be a neutrally balanced set up. But those 19"s...

Dinan on all four corners with the same tire configuration. Man those things are light! Not crazy about the finish with a Carbon Black car but I could always have them painted. But those 19's...

Now the BBS RG-R, love that Diamond Black finish and I think that would look great on Carbon Black. What? They don't come in 9.5" width's? Ahhhhh!!! The RS-GT's do!....but I don't like the lighter finish and not crazy about the exposed fasteners. What? They come in 19's?! But wait a minute what about that performance thing?

So let me throw out these scenarios with the BBS and someone let me know if they will work or if I am dreaming...

Option 1: BBS RG-R 19" x 10" 275/30's on all four corners.

Option 2: BBS RG-R 19" x 10" 275/30 front 285/30 rear.

Option 3: BBS RG-R 19" x 9" 275/30 front 19" x 10" 285/30 rear.

And no, I am not considering the 18's in BBS because I would just assume keep my OEM's or go with the Dinan's if that were the case. If one of these options will work and performance won't be that great of an issue, I just might get me some 19" BBS RG-R's

I applaude anyone and everyone who stumbled through this ramble

If you put 19's on your car, you'll be wasting the benefit of your new Stage 3 JRZ set-up. 19's not only degrade ride quality, handling suffers a lot as well (turn-in, deflection, compliant cornering set, etc). There's a reason hardly any 19", "R" compound tire sizes are available; those who care about handling won't use them.

Dinan wheels are extremely light (but strong forged aluminum), which, compared to stock or most other wheels, significantly reduces unsprung weight at the corners, which improves handling characteristics even more.

BTW, a member here had Dinan powder coat his wheel centers to a different color. I'm sure you can ask them to do the same.

FWIW, get 9x18 fronts, 9.5x18 rears; which have exact offset fitment, so no spacers or longer wheel bolts needed. Then forget about Mich PS-2's; get Toyo RA-1's (275/35/18's all around). Far, far superior tire in every way; except they'll wear faster. But you can mitigate that by going 9.5 front wheels (requiring 5mm spacers); so rotating them will work fine.

All of the above has nothing to do with tracking your car. I'm quite familiar with those great NorCal roads (1000's of miles between San Simeon, north to Eureka, everything in between, and all through inland valleys, foothills and mountains. 'Envy you being so close to all of that. So keep your car optimized for handling; you'll enjoy her more.

BTW, since you have your car at Dinan, ask to speak to Steve Dinan. Question him about wheels/tires for the JRZ set-up. Obviously, he'd like you to buy his wheels; but even if you stick with OEM's or go to some other wheels, I'm sure he'd advise to stay with 18's.

Just my 2 cents; but based on direct experience. Yes, I used to have lightweight Fikse 19's. Beautiful, but non-functional for handling.

Dan

aw/ir02smg · 18th February 2007, 10:18

[quote-drm64099]BTW, since you have your car at Dinan, ask to speak to Steve Dinan. Question him about wheels/tires for the JRZ set-up. Obviously, he'd like you to buy his wheels; but even if you stick with OEM's or go to some other wheels, I'm sure he'd advise to stay with 18's.

Just my 2 cents; but based on direct experience. Yes, I used to have Fikse 19's. Beautiful, but non-functional for handling.[/quote]

heykman (sorry for the semi-threadjack)...

dan,

you make me want to shed my 19s and go with my bbs rc...

Archille · 18th February 2007, 10:28

At the risk of being argumentative, I am in total disagreement with the Doc. My personal experience is totally opposite. All of the criteria the Doc described as negative attributes of 19" rims, I have to point out that rim size is only one contributor. What about suspension setup? Tire construction?...

I said it before and I am saying it once again, how long ago was it that cars rolled around in 14" or 15" rims, when Tirerack's +1 and +2 was 16" and 17"? Not that long ago that Indy cars raced on 16" rims. Why is 18" rim the optimum balance? What was the optimum rim to have before 18" came out? Most likely the assumption was based on what we can't do yesterday, but progress is made everyday to rid us of yesterday limitations. The argument that "the here and now" conventional wisdom as the greatest is short-sighted and silly. (Then again, it got Galileo ex-communicated by the Church, didn't it?!) What is now considered to be optimal was not and likely, will not be in the future. IMHO, a properly setup suspension, the latest high-performance tires, the latest forged Al wheels are just as good if not better than most of the 18" wheels setup out there.

So, who are these (people) that care about handling you are talking about? Eventhough, I have good background and experience to care greatly about handling of my vehicles, I certainly not one of them because I bought 19"...Rant off!!!

(...I apologize for off-tangent rant, Heykman. Good luck with your decision on the best rim for your need!!!)

Laidback · 18th February 2007, 10:44

Some interesting read ...i searched on the board Dinan Stage 3 and 19 " rims

Might consider another suspension if you wanna go 19's

DRM · 18th February 2007, 11:29

Quote:

Originally Posted by Archille

At the risk of being argumentative, I am in total disagreement with the Doc. My personal experience is totally opposite. All of the criteria the Doc described as negative attributes of 19" rims, I have to point out that rim size is only one contributor. What about suspension setup? Tire construction?...

I said it before and I am saying it once again, how long ago was it that cars rolled around in 14" or 15" rims, when Tirerack's +1 and +2 was 16" and 17"? Not that long ago that Indy cars raced on 16" rims. Why is 18" rim the optimum balance? What was the optimum rim to have before 18" came out? Most like the, the assumption was based on what we can't do yesterday but progress is made everyday to rid us of yesterday limitations. The argument that "the here and now" conventional wisdom as the greatest is short-sighted and silly. (But then again, it got Galileo ex-communicated by the Church, didn't it?!) What is now considered to be optimal was not and likely, will not be in the future.

So, who are these (people) that care about handling you are talking about?

'Sorry to light your fuse. 'Not a "doc", BTW. 'Retired (early by choice) banker.

You're right, wheel/tire size is NOT the absolute determinent of handling capability. Suspension components, set-up, vehicle weight, unsprung corner weight, etc., all have a bearing on how a car handles. If you read the first sentence of my post, I said he'd be wasting his new JRZ Stage 3 by using 19" wheels. Why? 'Cause that very expensive, multi component system was designed to be used with 18" wheels.

As for "who are these people?", off the top of my head I can name half a dozen very accomplished installers, fabricators, designers, users (or all four) who wouldn't consider 19" wheels. In fact, if you read about or go see amatuer club racing, any marque or venue, you'll find zero use of 19" or larger wheels. Hell, the vast army of Porsche guys actually DOWNSIZE their OEM 19's to 18", and even 17", to ACHIEVE BETTER HANDLING!! Turn-in and traction are the two most important aspects of wheels/tires. Bigger gets you more traction, smaller means better turn-in. So yes, 17" and 18" are considered a good balance to achieve both.

That said, you're right again; suspension systems can be built around 19", even 20" wheels. Dinan's already doing it for E60 M5's (with members here reporting glowing results); but Steve Dinan will also tell you BMW accepted trade-offs to accommodate those OEM 19" wheels. Electronic gizmo's can do a lot, but nothing can totally overcome pure physics.

Anyway, no argument intended or necessary. IMO (and he did ask), the OP shouldn't waste his money by using 19" wheels on an E39 M5 with a Dinan Stage 3 JRZ set-up. There'd be no point. If he wants 19" wheels that badly, then he ought to buy an appropriate suspension for them; a custom suspension fabricator/builder could do it for him.

Dan