F20/F21 · 2012–2015
The 125i is the most powerful four-cylinder petrol in the range: a 160 kW 2.0 turbo. Its servicing differs from the 1.6 models: more oil and an electronic oil level sensor.
Figures apply to the cited configuration and market; equipment and transmissions may vary by production date.
Specification source : [1] BMW Group [2] BMW Group [3] BMW Group
Figures published at launch for the cited manual configuration. Consumption is a test-cycle measurement, not a real-world guarantee; automatic versions may differ. Source [1]
1,997 cc four-cylinder turbo (engine code N20 in BMW’s parts catalogue): 160 kW at 5,000 rpm and 310 Nm from 1,350 to 4,800 rpm. Six-speed manual or eight-speed automatic. BMW quotes 6.4 s and 6.6 l/100 km for the manual. Five-door sheet valid from 03/2012; also offered as a three-door.
Oil change: 5.75 l according to BMW’s 2012 specification sheets (five- and three-door), more than a litre above the 116i and 118i. The N20 monitors oil level and temperature with a thermal oil level sensor. BMW-approved oils: Longlife-01, Longlife-01 FE or Longlife-04, in SAE 0W-40, 0W-30, 5W-40 or 5W-30. If none is available, BMW allows topping up with at most one litre of an ACEA A3/B4 oil. No additives.
At every oil service: oil, oil filter and cabin microfilter. At every second oil service: spark plugs and air filter. Front pads, rear pads, brake fluid and the vehicle check each have their own due date, calculated by the car from how it is used. BMW’s handbook gives no mileage for the oil service and no period for the brake fluid: the remaining distance or time appears briefly each time the ignition is switched on, with details in the service menu (“Service required” or INFO › SERV, depending on equipment).
Chain-driven, in two sections: the upper section drives the camshafts, the lower section the oil pump; an oil spray nozzle in the tensioner lubricates the chain. No scheduled replacement appears in the documents consulted.
Count oil services since the last spark plugs and air filter: both come round every second service. Give the service advisor the key the car was last driven with: BMW stores the maintenance need in it. If the battery was disconnected for a while, ask for the time-based items (brake fluid) to be updated.
Source : [13]
Due date calculated by CBS
The car calculates the due date from its operating conditions; BMW’s handbook sets no fixed mileage. Each oil service covers oil and filter, and it is the reference for the items below.
Source [13]At every oil service
On cars with air conditioning or automatic climate control, the microfilter is replaced at every oil service.
Source [13]Every 2nd oil service
Petrol engines: replaced at every second oil service. Keep count of oil services since the last change.
Source [13]Every 2nd oil service
Intake silencer element, replaced at every second oil service; shorter interval in very dusty conditions.
Source [13]Own CBS due date
Pads replaced, pad slots cleaned, disc surface and thickness checked, then the display is reset.
Source [13]Own CBS due date
Same work as at the front, plus a parking brake check on a roller test bench.
Source [13]Calendar-based (CBS)
Counted in time, not kilometres. Periods with the battery disconnected are not counted: have the workshop update the time-based items. The handbook does not state the period.
Source [13]Own CBS due date
Lights, seat belts, wipers, tyres, coolant, brake lines, underbody, steering, mobility kit and a road test.
Source [13]An N20, a 2.0 four-cylinder turbo, according to BMW’s parts catalogue. BMW lists 1,997 cc in its specification sheets but 1,995 cc in the summary of the 05/2012 three-door press kit.
BMW announced the 125i as EU6-compliant in three- and five-door form from autumn 2012; the 03/2012 sheet lists EU5. Check the registration document.
BMW’s sheets disagree: 6.5 s for the five-door (03/2012), 6.2 s for the three-door (07/2012). Consumption: 6.4 l/100 km against 6.6 l for the manual.
At every second oil service, together with the air filter, according to BMW’s F20/F21 handbook. The microfilter is changed at every oil service.
Source : [13]
BMW Group · EN · Europe (ACEA) · Valid from 3/2012 · five-door · pp. 1–2 · Accessed 08/10/2026
BMW Group · EN · Europe (ACEA) · PDF pp. 2–7 (summary, model variants), technical specifications from p. 22 · Accessed 08/10/2026
BMW Group · EN · Europe (ACEA) · Valid from 7/2012 · three-door · pp. 1–2 · Accessed 08/10/2026
BMW Group · EN · Europe · Sections on xDrive (120d xDrive, M135i xDrive), BMW 114d, three-door 120d/118i, EU6 · Accessed 08/10/2026
BMW Group · EN · Europe · Whole release: new four-cylinder diesels for the 5 Series; transmission and navigation updates for the 1 Series · Accessed 08/10/2026
BMW Group · EN · Europe (ACEA) · PDF pp. 2–8 (summary: lights, M135i 240 kW), pp. 22–24 (“five new diesel engines”) · Accessed 08/10/2026
BMW Austria · DE · Austria · “Neuer BMW 1er 3-türig (F21)” and “BMW 1er 5-türig (F20)” · kW/PS, l/100 km, CO2, EU class · Accessed 08/10/2026
BMW AG — Technical training (archive.org copy) · EN · Europe · Information status 11/2010 · §3.4.2 Oil level monitoring · §3.5.2 Chain drive · Accessed 08/10/2026
BMW AG (copy hosted by a third party) · EN · Europe · Part no. 01 40 2 900 802 · English II/12 · models 116i–125d · p. 28 (remote control), pp. 74–75 (service requirements, service history) · Accessed 08/10/2026
bmwfans.info (copy of the BMW ETK parts catalogue) · EN · Europe · Model list (model – engine), production years 2010–2015 · Accessed 08/10/2026
bmwfans.info (copy of the BMW ETK parts catalogue) · EN · Europe · Model list (model – engine) · Accessed 08/10/2026
bmwfans.info (copy of the BMW ETK parts catalogue) · EN · Europe · Group 11 · timing chain · Accessed 08/10/2026
BMW AG (copy hosted by kfz-handbuch.de) · DE · Germany · deutsch X/14 · p. 71 (Servicebedarf) · pp. 166–169 (Motoröl, freigegebene Motorölsorten) · pp. 172–174 (Wartung: CBS, Übersicht Wartungsumfänge) · Accessed 08/10/2026