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The CMST BMW F10 5 Series wheel upgrade is a set of 20-inch two-piece forged wheels built for the F10-generation 5 Series. Two-piece forged construction bolts a CNC-machined forged centre to a separately spun outer rim, which lets the wheel be made lighter and stiffer than a cast wheel while allowing custom widths, offsets and finishes. On a large saloon like the F10, the result is a lower, wider stance and reduced unsprung weight at each corner.

• Vehicle: BMW 5 Series (F10), including 520i to 535i and M5
• Fitment years: 2010-2017 (F10 5 Series)
• Size shown: 20-inch diameter, two-piece forged
• Construction: Forged centre bolted to a spun outer rim (two-piece)
• Finishes: Custom — gloss black or two-tone faces with a contrasting (for example red) outer lip

What two-piece forged wheels are

A forged wheel starts as a solid billet of aluminium that is compressed under enormous pressure into a dense, tightly grained blank, then CNC-machined into the finished centre. Forging aligns the metal's grain and removes the porosity you get in casting, so a forged wheel can be made thinner and lighter for the same strength — or stronger for the same weight. A two-piece design takes that forged centre and bolts it to a separately manufactured outer rim (the barrel), rather than producing the whole wheel as one piece. That split brings two advantages: the rim width and the centre's offset can be tailored to the car, and the two halves can be finished in different colours, which is how the contrasting-lip look is achieved. AME stocks the CMST programme alongside the wider CMST wheels for BMW range.

The F10 5 Series is a big, comfortable executive saloon — sold from the 520i through to the twin-turbo 535i and the V8 M5 — and it carries real mass. Reducing unsprung weight at each wheel is one of the most effective changes you can make to a heavy car: lighter wheels are easier for the suspension to control over bumps, which sharpens the way the car turns in and rides. Stepping up to 20-inch diameter also fills the F10's large wheel arches and lets the car run a wider, lower-profile tyre for a more planted look and feel.

Forged vs cast, and one-piece vs two-piece

Forged vs cast

Most factory and budget wheels are cast: molten aluminium is poured into a mould. Casting is cheap and fine for standard use, but the metal is less dense and the wheel must be made thicker to reach the required strength, which adds weight. Forging compresses the aluminium so the grain runs continuously through the wheel, giving a higher strength-to-weight ratio. For a performance-minded upgrade on a heavy saloon, forged is the construction that delivers genuine unsprung-weight savings rather than just a new look.

One-piece vs two-piece forged

A one-piece forged wheel is machined entirely from a single blank: it is the lightest and structurally simplest option, with no join between centre and rim. A two-piece forged wheel, like this CMST set, bolts a forged centre to a separately made outer rim. The benefit of two-piece is flexibility — the rim width, lip depth and centre offset can be specified to suit the car and the desired stance, and the two parts can be finished separately for a contrasting-lip look. The trade-off is a small weight and cost premium over an equivalent one-piece wheel, in exchange for that custom fitment and finish.

Sizing, fitment and stance

Wheel fitment on the F10 comes down to four numbers: diameter, width, offset and the centre bore and bolt pattern. The F10 uses BMW's 5x120 bolt pattern with a 72.5 mm centre bore, and the standard car runs staggered fitments (wider at the rear) on many variants. A 20-inch two-piece forged set lets you choose rim widths and offsets that tuck the wheel neatly into the arch for a flush, low stance, while keeping the tyre clear of the guard and suspension through full travel. Because the wheels are built to specification, the width and offset should be confirmed against your exact F10 variant, ride height and any suspension changes before ordering, so the finished fitment is both flush and free of rubbing.

Tyre choice on 20-inch wheels

Moving to 20-inch diameter usually means a lower-profile tyre to keep the rolling diameter close to standard, which preserves the speedometer reading and the car's gearing. A lower profile sharpens steering response and looks purposeful, but it leaves less sidewall to absorb sharp-edged bumps, so tyre choice matters on Australian roads. Your fitter can recommend a width and profile that balances the look with ride comfort and keeps the overall diameter sensible.

Finishes

The two-piece construction is what makes CMST's finish options possible. Because the forged centre and the outer rim are separate parts, they can be finished independently — a gloss black or machined centre face paired with a contrasting outer lip, as in the red-lipped set shown here, or a single uniform colour for a more restrained look. The centre can be powder-coated, painted or left with a machined face, and the lip can be polished or coloured. This is the practical advantage of two-piece forged wheels for buyers who want a specific look rather than an off-the-shelf finish. AME also lists the broader carbon fibre wheels range for owners exploring the next step in lightweight wheel construction.

Why forged wheels suit the F10

The F10 5 Series is heavy and rides on large arches, so it responds well to lighter wheels and a 20-inch diameter. Reducing unsprung mass helps the suspension keep the tyres in contact with the road, which improves both handling precision and ride quality, and the bigger diameter with a wider tyre fills the arches and gives the car the planted look its body deserves. A two-piece forged set adds the ability to tailor width, offset and finish to the exact car, so the upgrade is both functional and tuned to taste — the reason forged wheels remain the benchmark upgrade for executive saloons. See the full CMST catalogue for matching styling parts.

Frequently asked questions

Will these wheels fit my F10 5 Series?

The wheels are built for the F10-generation 5 Series, which uses a 5x120 bolt pattern and a 72.5 mm centre bore. Because they are two-piece forged wheels made to specification, the exact width and offset should be confirmed against your variant, ride height and any suspension setup before ordering, so the fitment is flush and clears the guards and suspension. Confirm your chassis is the F10 (2010-2017), not the newer G30 5 Series.

How much lighter are forged wheels than the factory wheels?

Forged construction has a higher strength-to-weight ratio than casting, so a forged wheel can be made lighter than a cast wheel of the same strength. The exact saving depends on the size, width and design chosen, so we do not quote a fixed figure, but the unsprung-weight reduction is the main functional reason owners choose forged over cast wheels on a heavy saloon like the F10.

What is the advantage of two-piece over one-piece forged?

A two-piece wheel bolts a forged centre to a separate outer rim, which lets you tailor the rim width, lip depth and offset to the car and finish the centre and lip in different colours. A one-piece forged wheel is lighter and simpler but less customisable. Two-piece is the choice when you want a specific stance and a contrasting-lip finish.

Do I need lower-profile tyres on 20-inch wheels?

Usually, yes. Going up to 20-inch diameter typically calls for a lower-profile tyre to keep the overall rolling diameter close to standard, which preserves your speedometer accuracy and gearing. A lower profile sharpens steering but leaves less sidewall cushioning, so choose a profile that suits your roads. Your fitter can recommend the right size.

Can I get a custom finish like the red lip?

Yes. Because the centre and rim are separate parts, they can be finished independently — for example a black or machined centre with a contrasting red outer lip, or a single uniform colour. The centre can be painted, powder-coated or machined, and the lip polished or coloured. Discuss your preferred finish with AME when specifying the wheels.

Should the wheels be fitted by a professional?

Yes. Forged wheels should be mounted and balanced by a workshop with the right equipment, torqued to specification, and checked for clearance against the guards, brakes and suspension through full travel. Professional fitment protects the wheels and ensures a safe, flush result on your F10.

If you are upgrading the wheels on an F10 BMW 5 Series, AME Motorsport can supply the CMST 20-inch two-piece forged set and confirm the right width, offset and finish for your car. Start with the CMST wheels for BMW range, then get in touch with your chassis details and any suspension changes so we can specify a fitment that sits flush and clears cleanly.