19 vs 20 wheels - Is it really that much of a difference?

[DownNOut]

I'm looking to buy a new set of wheels for my F06 and, so far, I have come up with two options:

BMW 703M 8.5x20 & 9x20

BMW 351 8.5x19 (front and rear) or 8.5x19 & 9x19

I never drove 20" wheels and, since I saw that many of you guys have 20" wheels on your BMW 6ers, I'd like to ask those among you who've had both those wheel sizes, is it really that much of a difference if both wheels are equipped with quality Michelin or Continental non RFT tires?

I read about so many horror stories of bumped wheels, bursted tires due to small potholes etc. and I'm seriously considering the 19s over the 20s just due to these horrible reports. Then there's this issue of driving comfort, which many claim renders the BMW 6ers almost unusable on even slightly less-than-ideal surfaces.

My F06 is mainly used for driving around Switzerland, which has, for the most part, very nice roads. I do want to occasionally visit Italy, which is known for bumpier roads, especially in the coastal regions, and I'm scared to burst my tires during my vacation just because I drove on southern Italian roads.

Is this fear of mine realistic or would you say that it's totally unnecessary as the F06 should handle the 20s as well as the 19s?

[Walt White Coupe]

If you go with a 20" wheel you have to go with a lower aspect ratio tire to fit the car and that means less rubber to flex and hence a harsher ride all else being equal. Less rubber also increases the problem of pothole damage. For your concern, I'd stick with a 19 inch wheel.

[Qsilver7]

I have my 18" winter tires on...and gotta confess...from the inside it is so much smoother/softer/compliant. I almost hate that the ambient temps are starting to creep higher where I need to take them off.

If I were to compare the 18" vs 20" wheel/tire setup...the 20s is like the car is wearing some sexy 3" high heels...and the 18s are like wearing a nice comfy pair of Hush Puppies.

If you go with the 20s...you do need to be aware of the roads you're driving on. If there are pot holes & heaved pavement or man covers that are low in the road or stick up high in the road...you may want to try to avoid them if at all possible. But despite the road hazard...they are still gosh darn sexy.

[JBF650]

RFT on 20" rims are ghastly and would be impossible to be described as comfortable. Hard choppy, crashy and noisy.

Michelin or Contis on 20" rims transformed my car yes, softer, less noise and much more forgiving of the odd divot or unavoidable pothole. I live in Sydney and our roads are not great, though our motorways are pretty well maintained. In saying that yes i do still avoid chopped out ruts and potholes where safe to do so as 20 rims simply don't have a lot of compliance with smaller profile rubber.... . yep the 20 look better than the 19' but not hugely so. I've run 20' rims now for 4 years and not had any issues. If you can cope with the odd bump and are reasonable aware and prepared to avoid potholes then go for the 20's if its too much of a risk stay with the 19'.

[DownNOut]

Thanks for the replies, guys!

I wish the 703M wheels would also be available in 19", that would've been the best of both worlds, good looks and less risk of wheel damage.

I still don't get why all the cool looking wheels are 20" exclusively. They would also look good in the 19" format All the BMW 19" wheels look almost geariatric whereas the 20" are just, and I agree with you Qsilver7, straight up sexy.

The 20" option doesn't sound as scary now as I thought it would be. The horror stories that I read were talking about busted tires from the dealership to the way home etc.

Did you guys had to replace any 20" wheels and blown out tires? Is it a very rare occurence?

Also, how long does a set of Continentals or Michelins last on your 20" wheels? Are we talking about 20'000 km or more like 10'000 km?

One other benefit that I read about the aforementioned 19" 351 wheels is that I could use the same wheels (8.5x19) for the front and rear axis and, I'm not sure if this is indeed true, but some people claim that it's much better for the xdrive drive train and axis to use the same wheels and tires on each position.

Don't know if there's any truth to it, as BMW has factory xdrive models that they ship out with broader rear wheels.

[shine775]

If you really want to run 20s, you can run a taller tire with more sidewall if you don't have xdrive. I have 245/40-20 on the front, 275/40-20 on the rear of my 2013 640i.

[Walt White Coupe]

"One other benefit that I read about the aforementioned 19" 351 wheels is that I could use the same wheels (8.5x19) for the front and rear axis and, I'm not sure if this is indeed true, but some people claim that it's much better for the xdrive drive train and axis to use the same wheels and tires on each position."

This is true.

[Opie55]

If the 703M wheels you are looking at are the wheels actually for an M6, they will not work on your car anyway. Not sure if those are or not, but thought I'd mention that.

[RJV3]

I have a similar question I'd like to present to the forum since I am in the same debate with 19's vs 20's. Currently on my F06 640I xdrive I have a squared set of 351's, but powder coated high gloss black. According to carsaddicts.com, the weight of the 351's are 32 lbs and I they are cast wheels. I was looking at a pair of flow forged Rohanna's with the same wheel specs as the 351's ( 5x120 +33mm offset 19's.) The main benefits of the flowforged wheels are a sturdier and tougher wheel at a fraction of the weight and cost of a true monoblock forged wheel. The Rohanna's are 22 pounds. At a 10lb per wheel weight saving, for sure the rotation force will equal a noticeable difference since the wheels are lighter. No effect to the speedometer due to the the diameter of the wheel being the same, and with NYC roads, I need all the sidewall on my tires I can get. Quicker acceleration for sure just off the weight. But the F06 is a over 4000 lbs in weight with the xdrive. My question is , will this lighter wheel be more durable and safer to ride on than the stock 351's? I've read on other posts that to be careful with lighter wheels for this car and even the F10's due to the weight of the car. If anyone can share some feedback on this it would be greatly appreciated.

[Walt White Coupe]

I changed my 19 inch 351's for 19 inch TSW Bathhurst wheels.

The 351's were 32 lbs each. The TSW's, that are flow forged, are 21 lbs each.

With the Goodyear Runflat All Season tires the combo for the 351's were 63.2 lbs.

The TSW's with Continental Non Runflat All Seasons were 45.2 lbs.

So I lost 18 lbs per wheel/tire.

The difference in ride was incredibly better with that change in every way.
Softer/Quiter/Smoother
It was like night and day.

As far as durable and safer to ride on than the stock 351's?? The 351's are cast beasts. But really all you have to do is compare the published weight that the wheel is made to support to determine if it's good for the car.



And while I liked the look of the 351's, I think the TSW's are beautiful in comparison. (I hate black wheels)

[JBF650]

I'm with you Walt, i loath this current craze of alloys all being black black black.... horrible IHO. I do like your white Coupe, its very svelte

As for the questions re how long with decent NON RFT last. depends of course how you drive the car. These cars are heavy and if driven hard they will used the rubber.

In saying that the Michelins pilots sport 4S on my 650 Coupe have lasted 3 years and 20,000 klms and are still fine i would say I will get another 20,000 out of them easily. I don't use my Beemer as a DD, its a weekender or 'get away' motorway cruiser for me so this will of course prolong the life of the tyres. Make sure you keep them properly inflated and check them. yes I know they all have TPMS but still its advisable to check any cars tyres every few months.
I've never had a wheel buckle, split or had a tyre burst either. Both my cars have 20" rims ( other car is a Range Rover Sport SC ) and they have been fine. I'm sure you will be ok and enjoy the car much better when you replace the awful RFT.

[Doughnutlord]

Originally Posted by Opie55

If the 703M wheels you are looking at are the wheels actually for an M6, they will not work on your car anyway. Not sure if those are or not, but thought I'd mention that.

Originally Posted by Opie55

If the 703M wheels you are looking at are the wheels actually for an M6, they will not work on your car anyway. Not sure if those are or not, but thought I'd mention that.

703M Wheels (at least in the UK) are the M Sport package upgrade wheels, not for the M6.

This is my 640d at the dealer with them on:

[TON-III]

Originally Posted by Walt White Coupe

I changed my 19 inch 351's for 19 inch TSW Bathhurst wheels.

The 351's were 32 lbs each. The TSW's, that are flow forged, are 21 lbs each.

With the Goodyear Runflat All Season tires the combo for the 351's were 63.2 lbs.

The TSW's with Continental Non Runflat All Seasons were 45.2 lbs.

So I lost 18 lbs per wheel/tire.

The difference in ride was incredibly better with that change in every way.
Softer/Quiter/Smoother
It was like night and day.

I've done like Walt, swapped from hefty weighty to relatively light combination build up with flow formed alloys. And yes, car was not that amusing earlier but now it's like a flying carpet, everything what car does it does it step or two better. Unsprung weight dropped 25 kg in total. So what ever your car weights the unsprung weight is essential.

[city1991]

Originally Posted by DownNOut

I'm looking to buy a new set of wheels for my F06 and, so far, I have come up with two options:

BMW 703M 8.5x20 & 9x20

BMW 351 8.5x19 (front and rear) or 8.5x19 & 9x19

I never drove 20" wheels and, since I saw that many of you guys have 20" wheels on your BMW 6ers, I'd like to ask those among you who've had both those wheel sizes, is it really that much of a difference if both wheels are equipped with quality Michelin or Continental non RFT tires?

I read about so many horror stories of bumped wheels, bursted tires due to small potholes etc. and I'm seriously considering the 19s over the 20s just due to these horrible reports. Then there's this issue of driving comfort, which many claim renders the BMW 6ers almost unusable on even slightly less-than-ideal surfaces.

My F06 is mainly used for driving around Switzerland, which has, for the most part, very nice roads. I do want to occasionally visit Italy, which is known for bumpier roads, especially in the coastal regions, and I'm scared to burst my tires during my vacation just because I drove on southern Italian roads.

Is this fear of mine realistic or would you say that it's totally unnecessary as the F06 should handle the 20s as well as the 19s?

Went to 19's and the ride quality is so much better than 20's.

[RJV3]

Originally Posted by TON-III

I've done like Walt, swapped from hefty weighty to relatively light combination build up with flow formed alloys. And yes, car was not that amusing earlier but now it's like a flying carpet, everything what car does it does it step or two better. Unsprung weight dropped 25 kg in total. So what ever your car weights the unsprung weight is essential.

How are you guys prepping for potential flat tires now that you no longer run RFT's? Spare in the trunk?

[Walt White Coupe]

The only flat tires I've ever had were slow leaks from a nail, screw, etc. and I've been driving 60 years. Every car of mine has a small air compressor in it. And with tire pressure sensors you will know if a tire is losing air. If it goes down overnight, just refill it to the max pressure on the tire and drive to where you are going or to a tire shop to get it fixed. In the totally unlikely odd event that a tire is totally blown, call AAA with your cell phone.

[Chaos236]

To original question,yes.

[JBF650]

Originally Posted by RJV3

How are you guys prepping for potential flat tires now that you no longer run RFT's? Spare in the trunk?

I carry a can of tyre foam in the boot in the unlikely event of a tyre puncture. and maybe a small air compressor if you do a lot of regional driving. I've been driving BMW's that have RFT for 20 years and swapped out the awful RFT asap. I always carry a foam spray in the boot for emergencies and up until this year I've never encountered a problem.

I did get a slow leak in one of my rear tyres over Xmas NY break actually, I was about 6 hours from Sydney in the country. The TPMS did pick this slow leak up and can you believe it it was a piece of bone that went through the side wall rendering the tyre safety compromised. It held air enough for me to have a plug put in it till I got back home and I replaced the tyre. Yes maybe if it was a run flat instead of conventional tyre it may not have happened but my kidneys and liver are still intact.

I would change any car over to conventional tyres over RFT no questions.

[TON-III]

Originally Posted by JBF650

I would change any car over to conventional tyres over RFT no questions.

+1


If there would be any magic with RF tyres all the racing and GT cars would use them .... those RF tires are that tough and heavy that those destroy driveability of your car.

[Qsilver7]

Originally Posted by RJV3

How are you guys prepping for potential flat tires now that you no longer run RFT's? Spare in the trunk?

I carry AAA roadside service...and I purchased the BMW tire mobility kit (combined air compressor with built in tire sealant in case its needed) and a plug kit.

[RJV3]

Originally Posted by Qsilver7

I carry AAA roadside service...and I purchased the BMW tire mobility kit (combined air compressor with built in tire sealant in case its needed) and a plug kit.

I see. Back in the day tire sealant on a tubeless tires was a no no. I guess all of that has changed now that BMW is offering their kit? Seriously considering non RFTs now

[MADEYE]

I went from 19" RFT's to 20" Alpina's and ditched the run flats.

Overall impression is ride quality improved slightly, tyre noise reduced significantly and slightly better handing.

But lost about 2mpg and doesn't coast as much in eco pro mode.

However the looks more then make up for that!