G20 / G21 · 2020–2022
The 318i G20 / G21 (2020–2022) produces 115 kW (156 hp). Entry-level petrol model added in March 2020: the same 2.0-litre B48 as the 320i, tuned to 115 kW.
Figures apply to the cited configuration and market; equipment and transmissions may vary by production date.
Specification source : [2] BMW Group [3] BMW Group [5] ADAC
115 kW (156 hp) and 250 Nm: four-cylinder petrol engine of 1,998 cc, engine code B48B20A according to ADAC. Period: 03/2020–06/2022 (ADAC dates). One page for the G20 saloon and the G21 Touring. Eight-speed Steptronic automatic. Rear-wheel drive only. 0–100 km/h in 8.4 s and 223 km/h for the saloon according to BMW (01/2020 sheet). Entry-level petrol model added in March 2020: the same 2.0-litre B48 as the 320i, tuned to 115 kW.
None of the BMW sheets we consulted for this period gives the oil-change quantity. The LCI specification sheet (05/2022) lists 5.25 l for the same engine at the same output: have it confirmed against the VIN. Approvals and viscosities: see the engine block below. The G20 handbook (2019–2022) describes electronic measurement: monitoring while driving (a value is available after about 30 minutes) and a detailed measurement with the car level, engine warm, selector in N or P, via CAR › Vehicle status › Engine oil level. Only top up when the message appears, by the quantity shown, without additives.
Petrol particulate filter according to ADAC; emissions standard Euro 6d-ISC-FCM.
Source : [5]
Condition Based Service calculates each due date from actual use; details appear in CAR › Vehicle status › Service requirements, together with the service history. The data are also stored in the key. BMW’s regular maintenance covers engine oil, brake fluid, a vehicle check, air filter, cabin microfilter and spark plugs. Brake fluid and, where applicable, oil and microfilter also depend on time; periods with the battery disconnected are not counted, so have the workshop update them. Neither the handbook nor BMW sets a mileage: the reference is the displayed date, which must not be exceeded.
ADAC lists for the 2019–2022 G20/G21: July 2026 (production 07/2020–02/2026) and February 2026 (05/2020–10/2024), wear deposits in the starter relay that can cause a short circuit and fire, starter replaced; October 2025 (09/2015–09/2021), starter relay insufficiently sealed against water, same remedy; May 2022 (01/2022–03/2022), faulty gas generator in the front belt pretensioners, belts checked and replaced if needed. Not every car built in a period is affected: have the VIN checked.
Source : [5]
Note the output (115 kW) and first-registration date on the registration certificate, then the due dates in the service requirements menu. Hand over the key used on the last drive: it holds the service data. Have the oil quantity confirmed against the VIN. Have the VIN checked for the recalls listed by ADAC and make sure the work is entered in the electronic service history.
This applies to every car fitted with the B48 engine.
Inline four-cylinder petrol engine of 1,998 cc (82 mm bore, 94.6 mm stroke) with twin-scroll turbocharger, direct injection, Valvetronic and double VANOS, from the modular “Bx8” family shared with the B38 three-cylinder. Codes found: B48B20M0 and B48B20O0 (2017 2 Series Convertible, 220i and 230i), B48B20B according to ADAC (2018 F30 330i, 185 kW/252 PS), B48A20T1 (F40 M135i xDrive, 225 kW/306 hp and 450 Nm). In BMW’s naming the “A” in B48A stands for a transversely installed petrol engine. It also powers the F45 220i/225i Active Tourer.
BMW handbooks only list oils for topping up and leave the oil change to a qualified workshop; the list depends on the handbook edition. 2 Series Active Tourer F45 handbook (II/17): BMW Longlife-01, -01 FE, -04, -12 FE or -14 FE+, in SAE 0W-40, 0W-30, 5W-40 or 5W-30 (0W-20 and 5W-20 only for certain engines); otherwise up to 1 litre of ACEA A3/B4. F45 facelift handbook (VI/19): BMW Longlife-04, -12 FE or -17 FE+, in SAE 0W-20, 5W-20, 0W-30, 5W-30, 0W-40 or 5W-40; otherwise up to 1 litre of ACEA C2 or C3. 1 Series F40 handbook (II/22) / 2 Series Coupé G42 handbook (VI/22): BMW Longlife-12 FE or -17 FE+, in SAE 0W-20 or 0W-30 only; otherwise up to 1 litre of ACEA C2 or C5. Active Tourer U06 handbook (X/24): BMW Longlife-12 FE, -17 FE+ or -19 FE, in SAE 0W-20 or 0W-30; otherwise up to 1 litre of ACEA C2, C3 or C5. No additives. Quantity published by BMW: 5.25 l for the B48B20M0 and B48B20O0 (2017 2 Series Convertible) and for the B48A20T1 (F40 M135i xDrive, oil-change quantity). No quantity is sourced here for other installations.
Chain, confirmed by ADAC. BMW’s Bx8 training document describes a two-part drive on the transmission side — a lower chain drives an intermediate shaft, which passes the drive to the upper camshaft chain — plus a separate chain for the oil/vacuum pump and spring-preloaded hydraulic tensioners; the inertia of the transmission reduces the loads on the chain. The sources consulted give no replacement interval.
2014: BMW introduces the Bx8 family; its June 2014 training document describes the B46 variant of this four-cylinder (X1, 231 hp and 350 Nm, 11:1 compression). 2018: the B48B20B of the F30 330i gains a gasoline particulate filter and meets Euro 6d-TEMP (ADAC). 2019: the B48A20T1 of the M135i xDrive, presented by BMW as its most powerful four-cylinder, gets a reinforced crankshaft drive with a larger main bearing, new pistons with altered compression ratio, unbushed con rods, a larger turbocharger with integrated manifold (exhaust temperatures up to 1,025 °C) and higher-flow injectors.
Due date calculated by CBS
Change the oil at the date the car displays, without exceeding it: the G20 handbook warns that oil changed too late increases engine wear. Between changes, only add the quantity the message asks for, using an approved oil and no additives.
Source [4]As the service requirement dictates
BMW lists as regular maintenance: brake fluid, a vehicle check to BMW specifications, air filter, cabin microfilter and spark plugs. Each item is triggered by the service requirement the car calculates.
Source [1]Calendar-based (CBS)
Brake fluid and, where applicable, engine oil and the microfilter/activated-carbon filter also depend on time. Periods with the battery disconnected are not taken into account: have the workshop update these items. The handbook gives no period.
Source [4]A four-cylinder petrol engine of 1,998 cc, code B48B20A according to ADAC, 03/2020–06/2022. The engine block below covers approved oils, timing drive and the history of this family.
None of the BMW sheets we consulted for this period gives the oil-change quantity. The LCI specification sheet (05/2022) lists 5.25 l for the same engine at the same output: have it confirmed against the VIN. This is a service quantity: check the electronic level afterwards.
Source : [3]
6.3 l/100 km combined WLTP for the saloon according to ADAC. Real figures depend on wheels, options and use.
Source : [5]
ADAC lists for the 2019–2022 G20/G21: July 2026 (production 07/2020–02/2026) and February 2026 (05/2020–10/2024), wear deposits in the starter relay that can cause a short circuit and fire, starter replaced; October 2025 (09/2015–09/2021), starter relay insufficiently sealed against water, same remedy; May 2022 (01/2022–03/2022), faulty gas generator in the front belt pretensioners, belts checked and replaced if needed. Not every car built in a period is affected: have the VIN checked.
Source : [5]
BMW AG · DE · Germany · Section “Die Leistungen von BMW Service Inclusive” · Accessed 08/10/2026
BMW Group · EN · Europe (German base data) · pp. 1–2 (48V mild hybrid standard in 320d and 320d xDrive Sedan/Touring from March/April 2020), p. 4 and table (new 318i Sedan/Touring: 115 kW/156 hp, 250 Nm, 8-speed Steptronic, 0–100 km/h, top speed) · Accessed 08/10/2026
BMW Group · EN · Europe (ACEA) · pp. 1–30 (scanned sheet, read by OCR); “Engine oil”, footnote 1) “Oil change volume”; outputs, 48V starter-generator, performance, WLTP · Accessed 08/10/2026
BMW AG (online copy: Kfz-Handbuch.de) · DE · Germany · pp. 167–168 (Servicebedarf, Service Historie), 312 (Einfahren), 366–368 (AdBlue), 369–372 (Motoröl, Ölmessung, Kühlmittel), 375–376 (Condition Based Service, Service Historie), 404 (Füllmengen) · Accessed 08/10/2026
ADAC · DE · Germany · Technische Daten: Motorart, Motorcode, Leistung, Drehmoment, Hubraum, Nockenwellensteuerung, Antriebsart, Getriebe, Modellstart/-ende, Schadstoffklasse, Abgasreinigung, Messwerte Hersteller; Rückrufe & Mängel · Accessed 08/10/2026
BMW Group · EN · Europe (ACEA) · PDF p. 2 (launch dates), pp. 13–14 (xDrive, limited-slip differential), pp. 16–20 (engines, transmissions) · Accessed 08/10/2026
BMW (UK) Ltd. · EN · United Kingdom · Basic data summary (engine description B38A15M1 / B48A20T1); Motor: “Engine oil (exchange quantity)” · Accessed 08/10/2026
BMW AG (online copy: Kfz-Handbuch.de) · DE · Germany · p. 182 (Servicebedarf), pp. 349–357 (Kraftstoff, AdBlue, Motoröl, Kühlmittel), pp. 360–361 (Condition Based Service, Service Historie) · Accessed 08/10/2026
BMW of North America — Technical training (archive.org copy) · EN · USA · Information status June 2014 · §1 (B38/B46, “Bx8”) · §2.2.7 Chain drive, Bx8 engines (pp. 57–58) · Accessed 08/10/2026
BMW of North America — Technical training (archive.org copy) · EN · USA · Information status April 2015 · §1.2 Modular design · §1.3 Technical data (engine oil specification) · §2.2.4 Chain drive · Accessed 08/10/2026
BMW AG (online copy: Kfz-Handbuch.de) · DE · Germany · p. 96 (Servicebedarf), pp. 214–215 (Kraftstoffqualität), pp. 231–234 (Motoröl), pp. 235–236 (Kühlmittel), pp. 237–238 (Condition Based Service, Service Historie) · Accessed 08/10/2026
BMW AG (online copy: Kfz-Handbuch.de) · DE · Germany · pp. 140–141 (Servicebedarf), pp. 270–273 (Kraftstoff, AdBlue), pp. 295–298 (Motoröl), pp. 299–300 (Kühlmittel), pp. 301–302 (Condition Based Service, Service Historie) · Accessed 08/10/2026
bmwfans.info (copy of the BMW ETK parts catalogue) · EN · Europe · Model, Engine: 214d/216d B37, 216i/218i B38, 218d/220d (and xDrive) B47, 220i/225i/225i xDrive B48, 225xe B38X · Accessed 08/10/2026
BMW Group UK · EN · United Kingdom · Effective production week 44/2017 · engine type (B38B15M0, B48B20M0, B48B20O0, B58B30M0, B47D20U0, B47D20O0, B47D20T0), gearbox, “Engine oil (filling quantity)” · Accessed 08/10/2026
BMW AG (online copy: Kfz-Handbuch.de) · DE · Germany · pp. 157–158 (Servicebedarf), 260–261 (Einfahren, Partikelfilter), 278 (Segeln), 311–315 (Kraftstoff, AdBlue), 316–321 (Motoröl, Kühlmittel), 322–323 (CBS, Service Historie), 326–328 (Batterie, Mild-Hybrid), 347–351 (Gewichte, Anhängelasten) · Accessed 08/10/2026
BMW AG (online copy: Kfz-Handbuch.de) · DE · Germany · pp. 170–171 (Service), 334 (Einfahren), 350–351 (Rekuperation, Segeln), 389–394 (Kraftstoff, AdBlue), 394–399 (Motoröl, Kühlmittel), 401 (CBS, Service Historie), 405–408 (Batterie, Mild-Hybrid), 412–413 (Starthilfe), 425–431 (Technische Daten) · Accessed 08/10/2026
ADAC · DE · Europe / Allemagne · B48B20B, 185 kW/252 PS, filtre à particules essence ; suffixe divergent du catalogue MANN. · Accessed 08/10/2026