Are the RS6 OEM wheels cast or forged?

[YashaR8]

trying to learn a thing or two about after market wheels and the different options before my RS6 arrives in a few months. Mostly curious about durability of the 22s in the land of massive northeast potholes. Knowing if our wheels are forged or not would be helpful when comparing to the aftermarket. Any thoughts would be appreciated, thanks guys1

-Yasha

[monugs]

trying to learn a thing or two about after market wheels and the different options before my RS6 arrives in a few months. Mostly curious about durability of the 22s in the land of massive northeast potholes. Knowing if our wheels are forged or not would be helpful when comparing to the aftermarket. Any thoughts would be appreciated, thanks guys1

-Yasha

cast aluminum

[S4-2-RS6]

For after market, a good middle ground is flow formed. Wheels made this way are lighter and more durable than a cast wheel, while not as expensive as full forged.

[OneFastBMW]

As mentioned the factory wheels are cast. You will not see forged factory wheels until you get into some very high-end sports cars.

From a metallurgy standpoint, forged is “stronger” than cast therefore an item made from a forged aluminum billet can be made using less material to get the same strength as a similar shaped item made of cast aluminum. Forged aluminum also has different failure characteristics. Cast materials will typically catastrophically fail by cracking (the stresses on the material exceed that materials tensile strength and the material separates). Forged materials typically have a higher tensile strength therefore the all other factors being equal, a forged piece will continue to deflect (bend) when a cast item cracks.

I have purposefully avoided saying “wheel” here because there is more to the strength of a wheel than just cast vs forged. Wheel design is probably just as important. You could design a cast wheel that is both stronger and lighter than a forged wheel. How we define how “strong” a wheel is also creates some discrepancies, for example on which axis the wheel is being tested matter.

“Flow Forming” is similar to an extruding process. A cast black is poured with the barrel of the wheel incomplete/in rough form. Using pressure and heat large rollers form the barrel of the wheel to the final specs. This extrusion process can increase the tensile strength of the material (but not to the extent of a forged wheel), resulting in a stronger barrel or a barrel of equal strength using less material (I.e. lighter). It is all a balance between strength and weight, but the center of the wheel and spokes are still a cast aluminum product.

Having said all this, most if not all of the higher-end aftermarket wheels (forged or flow formed) will exceed the strength of the factory wheels while also being lighter. Audi offers a good wheel/tire warranty that covers aftermarket wheels as long as they are the same size as factory wheels. This coverage is up to the cost of the OEM wheel, so don’t expect Audi to cover the full cost of a brand new HRE.

Generally I look for aftermarket wheels that are TUV certified.

[YashaR8]

thanks for the replies guys, lots of good info here. Appreciate the rundown, OneFastBMW

[CanAutM3]

As mentioned the factory wheels are cast. You will not see forged factory wheels until you get into some very high-end sports cars.

As a tidbit, the OE factory wheels on BMW ///M cars are mostly forged. My three previous M3/4, all much less expensive than the RS6, had forged wheels. It's a shame Audi cheeps out on their RS products with cast wheels, the RS6 wheels are bloody heavy.

[OneFastBMW]

As a tidbit, the OE factory wheels on BMW ///M cars are mostly forged. My three previous M3/4, all much less expensive than the RS6, had forged wheels. It's a shame Audi cheeps out on their RS products with cast wheels, the RS6 wheels are bloody heavy.

Thanks for that, I have been out of the M world since I the E70 X5M days, but it is good to know they are moving/have moved to forged.

You can generally tell by the “look” of the wheels if they are cast or forged. It you see thin spokes with lots of angles, that wheels is likely forged as casting such shapes is very difficult.

[monugs]

As a tidbit, the OE factory wheels on BMW ///M cars are mostly forged. My three previous M3/4, all much less expensive than the RS6, had forged wheels. It's a shame Audi cheeps out on their RS products with cast wheels, the RS6 wheels are bloody heavy.

Mercedes also offers a forged wheel on many of their AMG models. Agreed, shame Audi does not, especially in a wheel this size.

[GlazierGlaze]

As a tidbit, the OE factory wheels on BMW ///M cars are mostly forged. My three previous M3/4, all much less expensive than the RS6, had forged wheels. It's a shame Audi cheeps out on their RS products with cast wheels, the RS6 wheels are bloody heavy.

This.

[FBAnder]

As a tidbit, the OE factory wheels on BMW ///M cars are mostly forged. My three previous M3/4, all much less expensive than the RS6, had forged wheels. It's a shame Audi cheeps out on their RS products with cast wheels, the RS6 wheels are bloody heavy.

I learned this the hard way. I figured I had 19s on my S4, shouldn't be that much worse to haul the RS6 22s around. WRONG. I carried the RS6 22s up and down a flight of stairs ONCE when I first got the car. Once going down where I immediately said FUCK THIS I am not hauling these up and down stairs every year and once up the stairs taking them to get stored.

[essfour]

As a tidbit, the OE factory wheels on BMW ///M cars are mostly forged. My three previous M3/4, all much less expensive than the RS6, had forged wheels. It's a shame Audi cheeps out on their RS products with cast wheels, the RS6 wheels are bloody heavy.

The B8.5 RS5 oem 19in option was a forged factory wheel...

Anecdotally speaking I have had 2 of my factory forged 666m wheels replaced due to bending while I've never had issues with other cast wheels from Audi, BBS etc - all generally running identical tires/aspect ratios - again not a scientific measure, purely anecdotal.

Weight savings, particularly un-sprung, is a massive advantage to be sure - but does it matter when people are optioning their RS6's with hundreds of pounds of upgraded B&O magnets/speakers/subwoofers/wiring on an already 2+ ton car?

[OneFastBMW]

I would LOVE a factory forged option for weight savings!

Yes these cars are heavy, but rotating unsprung mass is the most impact mass to reduce on a vehicle. It affects acceleration, braking, handling, and ride quality. One reason I picked ceramic brakes was the 75 pound rotating, unsprung weight reduction.

The B8.5 RS5 oem 19in option was a forged factory wheel...

Anecdotally speaking I have had 2 of my factory forged 666m wheels replaced due to bending while I've never had issues with other cast wheels from Audi, BBS etc - all generally running identical tires/aspect ratios - again not a scientific measure, purely anecdotal.

Weight savings, particularly un-sprung, is a massive advantage to be sure - but does it matter when people are optioning their RS6's with hundreds of pounds of upgraded B&O magnets/speakers/subwoofers/wiring on an already 2+ ton car?

[87vr6]

You will not see forged factory wheels until you get into some very high-end sports cars.

That is very incorrect.

[OneFastBMW]

That is very incorrect.

It seems like manufacturers are catching up. Now the lower-tier sports cars like BMW M amd some AMG’s are getting forged wheels. Step it up Audi!!

[Jimminez@Nemesis]

B9 RS4/5 20” wheels are forged. I can’t image the price Audi would charge for 22” forged wheels. Think people are already shock by their asking price for cast 22”.

[phaphaphooey]

To pile on, the 20 inch C7 RS7 wheels are forged while the 21s are cast. Generally you are right though, until you get into true exotics/supercars, the wheels are cast instead of forged as a general rule.

[RMode]

RS5's are offered with factory forged wheels as well

[Brooklyn]

Don’t quote me on this, but could have sworn the 21” wheels on my wife’s 2019 E-Tron were forged. Stunned that the 22s on the RS6/7 are not.


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[rexus300]

Audi cast alloy are definitely more stronger than aftermarket cast alloy wheels and are just fine for the size. They are strong and don't bend over potholes compared to aftermarket. If I was getting aftermarket I tend to get forge. Regardless I am very happy with my 22s after 1.5 years on them in Michigan. I do use 21s for winters.