[BimmerV8]

Hi there
I'm new to this forum and I have few questions to all of you who have experience with mid-20 ETs and Micheiin Pilot Super Sport tires for the front.

Looking to order 20 inch wheels for the summer for my 550i xDrive M Sport.
The wheels I am considering as one of my favorites are HRE FF15 (Flow+Form).
Worth to mention that my car is lowered with Eibach Pro-Kit springs on the front 1.18" (30mm). It still looks decent but fully ok to me.

I have two (three) choices for the front wheels:
1. 20x8.5 ET30 with 245/35 Michelin PSS
2.a) 20x9 ET25 with 245/35 Michelin PSS
2.b) 20x9 ET25 with 255/35 Michelin PSS

the rear wheels:
20x10 ET40 with 285/30 if 2.a OR 295/30 if 2.b

as I have an xDrive model, I want the best possible circumfence which is in my case 245/285 OR 255/295.

Do you think the offset of ET25 will fit w/o problems on my lowered 550i and would you recommend the 255/35 PSS or is it safer to go with the 245/35 even though I do not like stretched tires (and to switch to 20x8.5 ET30?). My dealer told me that the 255/35 would be touching either the fender or inside the wheels base. Is he right?

Thanks in advance

[remmib]

I've got 20x9 ET26 with 255/35/20, without rubbing, so I'd get the 20x9 ET25 if I were you.

[BimmerV8]

Thank you remmib.
well ET26 should be almost identical, I guess. My dealer sounds quite sure that there will be some rubbing with 255/35. Don't know why.
In case I would chose the 245/35 instead, do you think the tire would show a big stretch on the 9" wide wheel compared to the 8.5"?
and what about the 20x10 for the rear? the 285/30 PSS should look perfectly squared. If so, than the 295/30 would look too wide? what do you think?
Thank you.

EDIT - the 20x9 ET25 wheels have a concave design; the 20X8.5 ET30 not. The rear wheels are concave anyhow. How does a F10 look like with concave wheels all around?

[.BMW.]

Originally Posted by BimmerV8

EDIT - the 20x9 ET25 wheels have a concave design; the 20X8.5 ET30 not. The rear wheels are concave anyhow. How does a F10 look like with concave wheels all around?

Take a look at Bossman535's F10 with concave Forgestar F14 wheels all around: f10.5post.com

[BimmerV8]

Originally Posted by .BMW.

Take a look at Bossman535's F10 with concave Forgestar F14 wheels all around: f10.5post.com

thanks. Yes, think it doesn't look bad at all (ok, Bossman's car is bad)

I went to remmib's thread where he was introducing his beatiful car with the HRE forged wheels. Simply
I still wonder whether a wheel with ET25 compared to ET26 with 255/35 PSS can have an issue with rubbing?
Does anyone have a pic of exactly the size I am looking for?

[remmib]

The difference between ET25 and ET26 is just 1mm, so very little, it won't show in pics.
Remember 1 inch is 25.4mm.

245/35/20 will look fine on 9", just a slight stretch, but I prefer 255/35.

M5 has 295/30/20 on 20x10 wheels, but 285/30 will look better.

[BimmerV8]

Originally Posted by remmib

The difference between ET25 and ET26 is just 1mm, so very little, it won't show in pics.
Remember 1 inch is 25.4mm.

245/35/20 will look fine on 9", just a slight stretch, but I prefer 255/35.

M5 has 295/30/20 on 20x10 wheels, but 285/30 will look better.

your car looks awesome!

yes, I am aware of it. 1mm is almost nothing. I do not like streched tires on wheels but even if I would go for the wider tires, thus 255/35 I guess I need 295/30 for the rear wheels. It is because I want the best possible circumference on both axles as I have xDrive (front/rear: 245/285 or 255/295). Ok, just went to https://www.rimsntires.com/specspro.jsp and the combination 255/285 gives me a difference in circumference of 0.9% compared to 255/295 where there is no difference (the same for 245/285). Maybe I am too cautious

[valbmw]

You are right with the last numbers.
Fronts/rears are of perfect fit if they are 245/285 (rims 8.5/10) and 255/295 (rims 9.0/10.5). No stretch, tires will be just flush to the lips.
The look will not be different, you won't notice this .5" of width but you will notice the cost of it.

[BimmerV8]

Originally Posted by valbmw

You are right with the last numbers.
Fronts/rears are of perfect fit if they are 245/285 (rims 8.5/10) and 255/295 (rims 9.0/10.5). No stretch, tires will be just flush to the lips.
The look will not be different, you won't notice this .5" of width but you will notice the cost of it.

thanks, valbmw, appreciate your comment. got it!
well, I could go with the 20x8.5 front wheel but I guess the ET30 will lead to the wheels to look almost the same as my OEM M351 19x8.5 wheels with ET33. In addition, I have Eibach springs which lowered the car a bit so I don't think it'll look the way I wanted to be. And I definitely don't want to use spacers.
what's your opinion? to take the 9" wheels and put 245 tires? the rear 10" wide wheels would get 285.
as rimmib also mentioned, the 295 on 10" width would be a bit too much of tire on the wheel.

So I could go with the 245 on the 20x9 taking into account the streched look of the tires... Thank you all for your inputs and suggestions

[.BMW.]

The OEM 20" staggered F10 setup differs by 0.9% and is avalible as an option with xDrive.
F: 245/35-20, 26.8"
R: 275/30-20, 26.5"

There is a rule of thumb to keep the difference below 1% with AWD. Also remember that if the tire diameter differs, the front should always be the one with higher rolling circumference.

Tire wear is also important in this discussion.
For example if the rear tires has worn out and the fronts still has some thread left:
New tires: 10/32"
Front tires: 4/32" (6/32" of the thread worn down per side means 3/8" shorter diameter)
Rear tires: 2/32" (8/32" of the thread worn down per side means 1/2" shorter diameter)

Tire diameters after the rear tires have been changed to new ones.
F: 26.8 - 3/8" = 26.4"
R: 26.5"

In summary even with OEM size where the front diameter is slightly larger than the rear it's really important to change all four tires at the same time. Or else there is always risk for damage to the drivetrain.

With this being said you could go with 255/285 tires, the differens is below 1%, the front is taller than the rear and the ratio is the same as for OEM 245/275 combo.

[exia_m3]

I'd go with 245/35 285/30
I had this on two different set ups
the stretch on 20x9 20x10 not even noticeable.
I have some pics of my new setup
which are Forgestars 20x9.5 and 20x11
there is very slight stretch for these widths.
http://f10.5post.com/forums/showthread.php?t=1190696

[BimmerV8]

Originally Posted by .BMW.

The OEM 20" staggered F10 setup differs by 0.9% and is avalible as an option with xDrive.
F: 245/35-20, 26.8"
R: 275/30-20, 26.5"

There is a rule of thumb to keep the difference below 1% with AWD. Also remember that if the tire diameter differs, the front should always be the one with higher rolling circumference.

In summary even with OEM size where the front diameter is slightly larger than the rear it's really important to change all four tires at the same time. Or else there is always risk for damage to the drivetrain.

With this being said you could go with 255/285 tires, the differens is below 1%, the front is taller than the rear and the ratio is the same as for OEM 245/275 combo.

Thank you, BMW!
highly appreciate your advises. The figures look crazy. Driving xDrive is a saftey privilege but certainly comes with cost + the fact that one more mechanical part of the car can get broken...particularly the splitter/distributor gear box which can react sensitive to unequal cirumferences.

you are right with the slighlty different tire diameters being present in 245/275 and 255/285 combo and indeed, the ratio is the same.
I guess I will leave 285 for the 20x10 for sure but for the front I am still unsure. Would love to have the 255 but rubbing is still a questionmark I guess.

[BimmerV8]

Originally Posted by xenoz535

I'd go with 245/35 285/30
I had this on two different set ups
the stretch on 20x9 20x10 not even noticeable.
I have some pics of my new setup
which are Forgestars 20x9.5 and 20x11
there is very slight stretch for these widths.
http://f10.5post.com/forums/showthread.php?t=1190696

many thanks, Xenoz! I would love to see your car and your tire/wheel setups. unfortunately, currently I am not able to see your pics on the PC I am using right now. Will do it at home.

[valbmw]

Originally Posted by BimmerV8

thanks, valbmw, appreciate your comment. got it!
well, I could go with the 20x8.5 front wheel but I guess the ET30 will lead to the wheels to look almost the same as my OEM M351 19x8.5 wheels with ET33. In addition, I have Eibach springs which lowered the car a bit so I don't think it'll look the way I wanted to be. And I definitely don't want to use spacers.
what's your opinion? to take the 9" wheels and put 245 tires? the rear 10" wide wheels would get 285.
as rimmib also mentioned, the 295 on 10" width would be a bit too much of tire on the wheel.

So I could go with the 245 on the 20x9 taking into account the streched look of the tires... Thank you all for your inputs and suggestions

Well, I am wondering why are you limited to some specific offsets, normally premium vendors offer you whatever you want. But once you said this is the case, OK let's take it as is.

The F: 20x9 ET25, 245/35 R: 20x10 ET40 285/30 looks the optimal option.

I have F: 20x8.5 ET20 245/35 R: 20x10 ET28 285/30. Michelin PSS provides a visible lip in the front, so the rears don't look level to the fronts, maybe a 5mm rear spacer wouldn't hurt See pics in my car's profile.

[BimmerV8]

Originally Posted by valbmw

Well, I am wondering why are you limited to some specific offsets, normally premium vendors offer you whatever you want. But once you said this is the case, OK let's take it as is.

The F: 20x9 ET25, 245/35 R: 20x10 ET40 285/30 looks the optimal option.

I have F: 20x8.5 ET20 245/35 R: 20x10 ET28 285/30. Michelin PSS provides a visible lip in the front, so the rears don't look level to the fronts, maybe a 5mm rear spacer wouldn't hurt See pics in my car's profile.

HRE offers now the flowform wheels next to the well-known forged wheels. Compared to the latter, the flowform wheels have their pre-defined range of offsets and this is why they can't be customized (except the color/finish). However, the price level is lower and due to the specific manufacturing process they undergo the stiffness is as similiar as forged wheels. And above all this, and what impresses me the most is the lightweight of those wheels. Depending of the size and offset, some are even lighter than forged wheels.

Thanks for your suggestion. I think I could live with the slightly strechted front tire then. I wouldn't want to use spacers if it's not that necessary. I will take a look at your pics again.

[valbmw]

HRE is my favorite brand And due to the 3-piece forged wheels are beautiful but damn too heavy, the next time I am about to consider a HRE monoblock.
Your current choice is smart and the wheels are great.

[BimmerV8]

been following them for years and I wouldn't choose any other aftermarket wheels. Those guys are damn good. Personally, I do like more the simple look so I would always go for monoblock forged wheels. And they are lighter than the 3-piece wheels. And I like spokes.
My absolute Nr 1 wheels in terms of design are the Alpina Classic wheels made by BBS. The only problem I would have are the stock offsets where I would be forced to use spacers.

back to the HRE FF15 wheels. The weight is incredible. I have calculated the weight difference between my current OEM 19" + Dunlop RFT setup and the FF15 20" + PSS. I come up to an overall saving of ~20kg (19.9kg) or 44lbs if I take the FF15.
I do not have the exact formula for rotating and unsprung mass but I guess the handling will be much better.
I think my bimmer will be grateful.

[BimmerV8]

HRE FF15 - only the wheel badge must come in the real HRE red/blue/white/silver colors.

[lsturbointeg]

gorgeous wheel...i considered the HRE FF01 but decided on something more aggressive!

[BimmerV8]

Originally Posted by lsturbointeg

gorgeous wheel...i considered the HRE FF01 but decided on something more aggressive!

Thanks! indeed and the more I look at them (FF15) the more I have to admit that the concave design makes them look much more nicer. There is a certain dynamics present and the eye never gets bored IMHO compared to straight running spokes.
This is why the Alpina Classic wheel with the turbine style spokes has an ageless design and will always look interesting (IMHO).

The FF01 are also good looking wheels, though slightly heavier. At the end, it's all about taste and preferences.

[.BMW.]

The HRE FF15 will look amazing on F10.

The spokes looks similar to the ones on Alpina wheels, but the HRE's have 15 spokes instead of 20 and an open design of the wheel centre which I prefer.

[BimmerV8]

Originally Posted by .BMW.

The HRE FF15 will look amazing on F10.

The spokes looks similar to the ones on Alpina wheels, but the HRE's have 15 spokes instead of 20 and an open design of the wheel centre which I prefer.

nothing against the 20 spokes on the Alpina wheels but the covered wheel centre and particularly the hidden valve is really an eye-catcher IMHO.

but, maybe some people are right saying Alpina wheels belong to Alpina cars...