Engine Parts for 2021 BMW X1

Page 21 of 295 · Fits your 2021 BMW X1

5,885 parts
Categories
Swag 15932947 — Engine Oil
Swag
15932947

Engine Oil

Fits 18 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
  • 2020– xDrive 25 e Plug-in-Hybrid All-wheel Drive · SUV B38 A15 A 1.5L Petrol/Electric 162 kW
  • 2020– sDrive 20 i Front-Wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
  • 2020– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
Swag 15932948 — Engine Oil
Swag
15932948

Engine Oil

Fits 18 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
  • 2020– xDrive 25 e Plug-in-Hybrid All-wheel Drive · SUV B38 A15 A 1.5L Petrol/Electric 162 kW
  • 2020– sDrive 20 i Front-Wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
  • 2020– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
Victor Reinz 15-10045-01 — Gasket Set, cylinder head cover
Victor Reinz OEM
15-10045-01

Gasket Set, cylinder head cover

Fits 9 versions of your 2021 BMW X1
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
Victor Reinz 15-10048-01 — Gasket Set, oil cooler
Victor Reinz OEM
15-10048-01

Gasket Set, oil cooler

Fits 2 versions of your 2021 BMW X1
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
Victor Reinz 15-10930-01 — Gasket Set, cylinder head cover
Victor Reinz OEM
15-10930-01

Gasket Set, cylinder head cover

Fits 3 versions of your 2021 BMW X1
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
Victor Reinz 15-11208-01 — Gasket Set, cylinder head cover
Victor Reinz OEM
15-11208-01

Gasket Set, cylinder head cover

Fits 1 version of your 2021 BMW X1
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
Victor Reinz 15-12257-01 — Gasket Set, cylinder head cover
Victor Reinz OEM
15-12257-01

Gasket Set, cylinder head cover

Fits 1 version of your 2021 BMW X1
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
IPD 15-4154 — Belt Tensioner, V-ribbed belt
IPD
15-4154

Belt Tensioner, V-ribbed belt

Fits 5 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
IPD 15-4253 — Deflection/Guide Pulley, V-ribbed belt
IPD
15-4253

Deflection/Guide Pulley, V-ribbed belt

Fits 15 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
IPD 15-4285 — Belt Tensioner, V-ribbed belt
IPD
15-4285

Belt Tensioner, V-ribbed belt

Fits 9 versions of your 2021 BMW X1
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
Akron-Malò 1500359 — Air Filter
Akron-Malò
1500359

Air Filter

Fits 16 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
  • 2020– xDrive 25 e Plug-in-Hybrid All-wheel Drive · SUV B38 A15 A 1.5L Petrol/Electric 162 kW
  • 2020– sDrive 20 i Front-Wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
  • 2020– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
Ajusa 15075200 — Shaft Seal, crankshaft
Ajusa
15075200

Shaft Seal, crankshaft

Fits 5 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2020– sDrive 20 i Front-Wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
  • 2020– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
Ajusa 15095200 — Shaft Seal, crankshaft
Ajusa
15095200

Shaft Seal, crankshaft

Fits 9 versions of your 2021 BMW X1
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
Ajusa 15095300 — Shaft Seal, crankshaft
Ajusa
15095300

Shaft Seal, crankshaft

Fits 10 versions of your 2021 BMW X1
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
Akron-Malò 1510252 — Oil Filter
Akron-Malò
1510252

Oil Filter

Fits 15 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
  • 2020– sDrive 20 i Front-Wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
  • 2020– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
Ajusa 15107900 — Shaft Seal, crankshaft
Ajusa
15107900

Shaft Seal, crankshaft

Fits 8 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
  • 2020– xDrive 25 e Plug-in-Hybrid All-wheel Drive · SUV B38 A15 A 1.5L Petrol/Electric 162 kW
  • 2020– sDrive 20 i Front-Wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
  • 2020– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 131 kW
Elwis Royal 1515460 — Gasket, cylinder head cover
Elwis Royal
1515460

Gasket, cylinder head cover

Fits 3 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
Magneti Marelli 153071762360 — Air Filter
Magneti Marelli OEM
153071762360

Air Filter

Fits 4 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
Magneti Marelli 153071762361 — Air Filter
Magneti Marelli OEM
153071762361

Air Filter

Fits 13 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2017– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 103 kW
Magneti Marelli 153071762441 — Oil Filter
Magneti Marelli OEM
153071762441

Oil Filter

Fits 14 versions of your 2021 BMW X1
  • 2015– xDrive 20 i All-wheel Drive · SUV B48 A20 A 2.0L Petrol 141 kW
  • 2015– xDrive 25 i All-wheel Drive · SUV B42 S20 A 2.0L Petrol 170 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2014– xDrive 25 d All-wheel Drive · SUV B47 C20 B 2.0L Diesel 170 kW
  • 2015– sDrive 18 i Front-Wheel Drive · SUV B38 A15 A 1.5L Petrol 100 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 110 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2015– sDrive 20 i Front-Wheel Drive · SUV B42 S20 A 2.0L Petrol 141 kW
  • 2015– sDrive 18 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW
  • 2015– xDrive 20 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 140 kW
  • 2014– sDrive 16 d Front-Wheel Drive · SUV B37 C15 A 1.5L Diesel 85 kW
  • 2015– sDrive 20 d Front-Wheel Drive · SUV B47 C20 A 2.0L Diesel 120 kW
  • 2014– xDrive 18 d All-wheel Drive · SUV B47 C20 A 2.0L Diesel 100 kW