Onyx Forged
FREN

Custom forged wheels for BMW M340i G20 and G21 (2019-present)

Technical specifications

Production period
2019-present

Original fitment measurements: BMW M340i G20 and G21

The measurements of the car as delivered new, to identify yours and compare. Each value refers, by a number, to the sources that give it. They are not a recommendation: Onyx does not advise any specific offset.

Hub

MeasurementOriginal value
PCD (bolt pattern)5x112 [1, 2, 3, 4, 5, 6]
Centre bore66.6 mm [2, 3, 4, 5, 6]
ThreadM14 x 1.25 [2, 3, 4, 5, 6]
FixingWheel bolts [2, 3, 4, 5, 6]
Bolt or nut seatNot published
Tightening torque140 Nm [2, 3, 5]

“Not published”: no source gives it with the certainty we require at this stage (see the rule below).

Original fitments by version

Version and fitmentFrontRear
DiameterWidthOriginal offset (manufacturer)TyreDiameterWidthOriginal offset (manufacturer)Tyre
M340i xDrive Saloon (G20), 275 kW, 19 inches, original equipment19″ [7, 8, 9, 10]8J [7, 8, 9, 10]ET 27 [7, 8, 9, 10]225/40 R19 [7, 8, 9, 10]19″ [7, 8, 9, 10]8.5J [7, 8, 9, 10]ET 40 [7, 8, 9, 10]255/35 R19 [7, 8, 9, 10]
M340i xDrive Saloon (G20), 275 kW, 18 inches, original equipment18″ [7, 8, 9, 10]7.5J [7, 8, 9, 10]ET 25 [7, 8, 9, 10]225/45 R18 [7, 8, 9, 10]18″ [7, 8, 9, 10]8.5J [7, 8, 9, 10]ET 40 [7, 8, 9, 10]255/40 R18 [7, 8, 9, 10]
M340i xDrive Saloon (G20), 275 kW, 20 inches, original equipment20″ [7, 8, 9, 10]8J [7, 8, 9, 10]ET 27 [7, 8, 9, 10]225/35 R20 [7, 8, 9, 10]20″ [7, 8, 9, 10]8.5J [7, 8, 9, 10]ET 40 [7, 8, 9, 10]255/30 R20 [7, 8, 9, 10]
M340i xDrive Saloon (G20), 275 kW, 18 inches, winter tyres, original equipment (winter tyres)18″ [7, 8, 9, 10]7.5J [7, 8, 9, 10]ET 25 [7, 8, 9, 10]225/45 R18 [7, 8, 9, 10]18″ [7, 8, 9, 10]7.5J [7, 8, 9, 10]ET 25 [7, 8, 9, 10]225/45 R18 [7, 8, 9, 10]
M340i xDrive Touring (G21), 275 kW, 19 inches, original equipment19″ [11, 12, 13]8J [11, 12, 13]ET 27 [11, 12, 13]225/40 R19 [11, 12, 13]19″ [11, 12, 13]8.5J [11, 12, 13]ET 40 [11, 12, 13]255/35 R19 [11, 12, 13]
M340i xDrive Touring (G21), 275 kW, 18 inches, original equipment18″ [11, 12, 13]7.5J [11, 12, 13]ET 25 [11, 12, 13]225/45 R18 [11, 12, 13]18″ [11, 12, 13]8.5J [11, 12, 13]ET 40 [11, 12, 13]255/40 R18 [11, 12, 13]
M340i xDrive Touring (G21), 275 kW, 18 inches, winter tyres, original equipment (winter tyres)18″ [11, 12, 13]7.5J [11, 12, 13]ET 25 [11, 12, 13]225/45 R18 [11, 12, 13]18″ [11, 12, 13]7.5J [11, 12, 13]ET 25 [11, 12, 13]225/45 R18 [11, 12, 13]

The offsets are the original ones, given by the manufacturer or by the sources cited; they help you identify your car's fitment.

What Onyx can make for the BMW M340i G20 and G21

Custom forged wheels in forged 6061-T6 aluminium, designed to JWL/VIA standards, in monoblock or two-piece construction; three-piece wheels are made on quotation.

The diameters below start at the smallest original diameter recorded on this car (18″) and go up to 24″.

DiameterMonoblock, set of four wheelsTwo-piece, set of four wheels
18″€3,200
Great Britain: £3,336 with UK import VAT		€4,300
Great Britain: £4,482 with UK import VAT
19″€3,200
Great Britain: £3,336 with UK import VAT		€4,300
Great Britain: £4,482 with UK import VAT
20″€3,300
Great Britain: £3,440.40 with UK import VAT		€4,400
Great Britain: £4,586.40 with UK import VAT
21″€3,550
Great Britain: £3,700.80 with UK import VAT		€4,750
Great Britain: £4,951.20 with UK import VAT
22″€3,750
Great Britain: £3,908.40 with UK import VAT		€5,200
Great Britain: £5,420.40 with UK import VAT
23″€3,950
Great Britain: £4,117.20 with UK import VAT		€5,750
Great Britain: £5,992.80 with UK import VAT
24″€4,100
Great Britain: £4,273.20 with UK import VAT		€6,300
Great Britain: £6,566.40 with UK import VAT

Amounts in pounds: our checkout on 4 October 2026, before the carrier's clearance fee and any import duty. The amount shown at checkout is the one charged for your order.

Wheels delivered in 4 to 8 working weeks, shipping included, from full payment for an order on the website, or from the deposit for an order on quotation, and at the earliest from your approval of the measurements, the colour or the 3D render you asked for, under article 5.1 of the Terms and Conditions.

The offset and width of your wheels do not come from a table: the Onyx Forged design office calculates them for your car and your brakes, and submits them to you before machining.

Configure wheels for the BMW M340i G20 and G21

Frequently asked questions: wheels for the BMW M340i G20 and G21

What are the original offsets for the wheels of a BMW M340i (G20 and G21)?

A staggered fitment, according to its Swiss vehicle type records: 8J with an offset of 27 at the front and 8.5J with an offset of 40 at the rear, in both 19 and 20 inches; in 18 inches, 7.5J with an offset of 25 at the front and 8.5J with an offset of 40 at the rear. The 20-inch wheel is not permitted on the Touring. [7, 10, 11, 13]

Which tyres, and which load index, does a BMW M340i (G20 and G21) take?

In 19 inches, 225/40 R19 with load index 93 at the front, i.e. 650 kg per tyre, and 255/35 R19 with load index 96 at the rear, i.e. 710 kg; in 18 inches, 225/45 R18 with load index 95 and 255/40 R18 with load index 99, i.e. 690 and 775 kg; in 20 inches, 225/35 R20 with load index 90 and 255/30 R20 with load index 92. [7, 10, 14]

What is the load per wheel on a BMW M340i (G20 and G21)?

The Saloon's Swiss vehicle type record gives it a permissible load of 1,115 kg on the front axle and 1,230 kg on the rear axle, i.e. 557.5 and 615 kg per wheel; the Touring's record of June 2023 gives 1,350 kg at the rear, i.e. 675 kg per wheel. The 255/40 R18 rear tyre with load index 99 carries 775 kg. [7, 13, 14]

What PCD, centre bore and bolts does a BMW M340i (G20 and G21) use?

The PCD is 5x112, the centre bore 66.6 mm, and the wheels are held by M14 x 1.25 bolts tightened to 140 Nm: koleso.ee and SCC give these measurements, as does wheelfitment.eu, with a lower torque; hubcentric-rings.com gives the same PCD but a different centre bore, which we do not adopt. [1, 2, 3, 4, 5, 6]

Same fixing measurements

As original equipment, these cars have the same PCD, centre bore, thread and fixing as the BMW M340i G20 and G21: PCD 5x112, centre bore 66.6 mm, thread M14 x 1.25, fixing: wheel bolts.

Same fixing measurements; original diameters and offsets: see each car's page. The seat of the bolts or nuts, the width of the wheels and brake clearance are not compared here: this comparison is not an opinion on compatibility.

Sources for the measurements and answers

  1. hubcentric-rings.com, BMW 3 Series (“G20/G21 (2019–)” row) (secondary source, consulted on 21 October 2026)
  2. koleso.ee, BMW 3 Series VII (G20/G21/G28) [2018 .. 2022], M340i xDrive (secondary source, consulted on 21 October 2026)
  3. SCC Fahrzeugtechnik (spurverbreiterung.de), BMW 3er, type G20, 2019 onwards (secondary source, consulted on 21 October 2026)
  4. wheelfitment.eu, BMW 3 Serie G20-G21 (2019 - ) (secondary source, consulted on 21 October 2026)
  5. koleso.ee, BMW 3 Series VII LCI (G20/G21/G28) [2022 .. 2024], M340i xDrive (secondary source, consulted on 21 October 2026)
  6. SCC Fahrzeugtechnik (spurverbreiterung.de), BMW 3er Touring, type G21, 2019 onwards (secondary source, consulted on 21 October 2026)
  7. Swiss Federal Roads Office (ASTRA), vehicle type record no. 1BP944 (BMW M340i xDrive Saloon, type G3L (G20), 275 kW, July 2019): permitted tyre and wheel combinations (tyre, width x diameter, offset) and axle loads (primary source, consulted on 21 October 2026)
  8. Swiss Federal Roads Office (ASTRA), vehicle type record no. 1BS686 (BMW M340i xDrive Saloon, type G3L (G20), 275 kW, November 2020): permitted tyre and wheel combinations (tyre, width x diameter, offset) and axle loads (primary source, consulted on 21 October 2026)
  9. Swiss Federal Roads Office (ASTRA), vehicle type record no. 1BV119 (BMW M340i xDrive Saloon, type G3L (G20), 275 kW, January 2021): permitted tyre and wheel combinations (tyre, width x diameter, offset) and axle loads (primary source, consulted on 21 October 2026)
  10. Swiss Federal Roads Office (ASTRA), vehicle type record no. ABB559 (BMW M340i xDrive Saloon, type G3L (G20), 275 kW, June 2023): permitted tyre and wheel combinations (tyre, width x diameter, offset) and axle loads (primary source, consulted on 21 October 2026)
  11. Swiss Federal Roads Office (ASTRA), vehicle type record no. 1BQ606 (BMW M340i xDrive Touring, type G3K (G21), 275 kW, November 2019): permitted tyre and wheel combinations (tyre, width x diameter, offset) and axle loads (primary source, consulted on 21 October 2026)
  12. Swiss Federal Roads Office (ASTRA), vehicle type record no. 1XV790 (BMW M340i xDrive Touring, type G3K (G21), 275 kW, November 2020): permitted tyre and wheel combinations (tyre, width x diameter, offset) and axle loads (primary source, consulted on 21 October 2026)
  13. Swiss Federal Roads Office (ASTRA), vehicle type record no. ABB476 (BMW M340i xDrive Touring, type G3K (G21), 275 kW, June 2023): permitted tyre and wheel combinations (tyre, width x diameter, offset) and axle loads (primary source, consulted on 21 October 2026)
  14. Fiches-auto.fr, tyre load index table (index → kg) (reference table, for a conversion, consulted on 3 October 2026)

Publication rule: a measurement is shown only if a primary source gives it (a manufacturer's document, an official vehicle type record, an original parts catalogue, the maker of the original wheel) without another primary source contradicting it, or if two independent specialist sources agree without a primary source contradicting them. The press and forums do not count. Measurements checked on 21 October 2026 by the Onyx Forged design office.

Designs for this generation

Three models from our catalogue, forged to measure for your BMW M340i G20 and G21. The price is for a set of four wheels: it depends on the construction and the diameter.

Amounts in pounds: our checkout on 4 October 2026, before the carrier's clearance fee and any import duty. The amount shown at checkout is the one charged for your order.

Find my wheel · All 24 designs in the catalogue

See these wheels on your car

Custom forged wheels for the BMW M340i G20 and G21

  • Forged 6061-T6 aluminium
  • 5-axis CNC machining
  • Designed to JWL/VIA standards
  • Fitment worked out for your BMW M340i G20 and G21

M340i G20 and G21: 5x112, a 66.6 mm hub, M14 x 1.25 bolts

The BMW M340i xDrive, as a Saloon (G20) and as a Touring (G21), whose first Swiss vehicle type records date from July and November 2019, is 5x112 on a 66.6 mm hub, with M14 x 1.25 wheel bolts tightened to 140 Nm: koleso.ee and SCC give these measurements, as does wheelfitment.eu, with a lower torque, each cited in the table. hubcentric-rings.com gives the same PCD (bolt pattern) but a different centre bore, which we do not adopt, as on the 3 Series G20 page.

A staggered fitment, from 18 to 20 inches

The vehicle type record of the Swiss Federal Roads Office (ASTRA), the document that sets the tyre and wheel combinations a car may carry, permits for the 275 kW M340i a staggered fitment, wider at the rear: 8J with an offset of 27 at the front and 8.5J with an offset of 40 at the rear, in 19 inches (225/40 R19 and 255/35 R19) as well as in 20 inches (225/35 R20 and 255/30 R20); in 18 inches, 7.5J with an offset of 25 at the front and 8.5J with an offset of 40 at the rear (225/45 R18 and 255/40 R18). The 20-inch wheel is not permitted on the Touring. For winter, the record permits 7.5J x 18 with an offset of 25 on both axles. The record lists the front wheels in one field and the rear wheels in the next; the table pairs them in that order, as for the Z4 G29 and the GR Supra, which share this format.

The rear carries the most, especially on the Touring

The Saloon's record gives a permissible load of 1,115 kg on the front axle and 1,230 kg on the rear axle, i.e. 557.5 and 615 kg per wheel; the Touring's record of June 2023 gives 1,350 kg at the rear, i.e. 675 kg per wheel. That is the load the rear wheel must carry, and the rear tyre must keep at least the load index of the original fitment, 99 for 255/40 R18 (reading a tyre (page in French)).

What these measurements say about a forged wheel

The offset positions the wheel in the wheel arch: a wider wheel, or a lower offset, brings it closer to the wing. The Onyx Forged design office starts from the measurements on this page, your brakes and your tyres to calculate the width and offset of your wheels, then submits them to you. The offset calculator compares two fitments: it compares, it does not choose the measurement for you.

Roadworthiness test: what is examined

The French roadworthiness test (contrôle technique) examines the wheel without removing it (cracks, deformation, a wheel that protrudes beyond the bodywork) and verifies that the tyre size is one provided for by the manufacturer or accepted as equivalent. Keeping a tyre size from the original fitment, and at least its load index, avoids having to justify it; the details are on the roadworthiness test and registration page.

What we record before machining

Configure your forged wheels for the BMW M340i (G20 or G21)

The Onyx Forged design office works out the measurements of your car from its exact version, stated on the registration document, and shows them to you before machining. Each set is cut from forged 6061-T6 aluminium, machined on a 5-axis CNC centre, as monoblock, two-piece or three-piece wheels; our wheels are designed to JWL/VIA standards. Prices by diameter and the lead time are given on this page, under “What Onyx can make”. Start your configuration or write to contact@onyxforgedwheels.com.

Configure custom wheels for your BMW M340i G20 and G21: free 3D render, on request.

Useful guides

See all BMW models.