Engine cooling
More informationAt the Global Parts automotive store, we offer a wide selection of original used car parts, including engine cooling components, for many popular car brands such as BMW, Mini, Mercedes, Audi, Volkswagen, and others. Each of our car parts undergoes quality control to ensure you receive a top-quality product.
Make
Category
Subcategory
Condition
In Stock
Price
Part no. 7640287
Coolant Hose BMW F20 F21 F30 F31 LCI Gearbox Oil Heat Exchanger Hose 7640287
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 7600586-1
BMW F20 F30 F31 N13 Thermostat Coolant Flange 7600586 11537600586
PLN 75.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7395933
Water Pump BMW F45 225xe Mini F60 SE ALL4 Auxiliary Coolant Pump Hybrid 7395933
PLN 189.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7519256
BMW E60 E61 M54 Petrol Engine Cooling Radiator Supply Hose 7519256
PLN 85.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8517969
Water Hose BMW X5 F15 X6 F16 N57N N57Z Radiator Coolant Pipe Line 8517969
PLN 123.95
Free delivery: Mar 20
If paid before 14:00
Part no. 9166925
BMW X3 F25 N47N Diesel Engine Water Hose Coolant Cooling Pipe Line 9166925
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 7619684
Coolant Hose BMW F10 F11 N20 520i 528i Radiator Water Cooling Top Pipe 7619684
PLN 61.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7800489
BMW 5 Series E60 E61 LCI M47N2 Gearbox Oil Cooling Pipe Inlet Outlet 7800489
PLN 56.95
Delivery: Mar 20 – 23
If paid before 14:00
Part no. 7192198
BMW Z4 E89 Roadster Lateral Air Flap Duct Control Cover Right O/S 7192198
PLN 237.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 7593141
BMW F01 F02 F10 F11 N53 Oil Cooler Cooling Pipe Hose Line Tube 7593141
PLN 113.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7600511
BMW F20 F21 F30 F31 Radiator Engine Cooling 7600511
PLN 142.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7591092
BMW F01 F02 F03 F10 F11 Coolant Cooling Pipe Hose Line Petrol Engine 7591092
PLN 61.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7592723
BMW F80 M3 F82 F83 M4 LCI Transmission Oil Cooler Line Flow Pipe
PLN 142.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 8513842
BMW F10 F20 LCI F30 F32 B47 Engine Cylinder Head Mounting Holder Loop 8513842
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 7583836
BMW F10 F11 F01 F25 N52N N53 Coolant Electrical Water Pump 7583836
PLN 408.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7552405
BMW E81 E82 E87 LCI E87N Line Heater Return Thermostat Engine Cooling
PLN 75.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 7645523
Water Hose BMW F45 Mini F60 Radiator Coolant Hose Pipe Line 7645523
PLN 113.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7601176-3
Radiator Fan BMW X3 F25 X4 F26 Engine Cooling Cooler Unit 7601176
PLN 142.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 8631692-1
BMW F20 F21 F30 F31 LCI F22 F32 F36 B38 Petrol Water Pump Wheel Pulley 8631692
PLN 75.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8645480
BMW X1 E84 Mini F55 F56 F60 Water Hose Radiator Engine Coolant Pipe Line 2367292
PLN 61.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8089488
BMW F87 LCI M2 Competition Expansion Tank Reservoir Bottle 8089488
PLN 189.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7835220-1
BMW 5 6 E60 M5 E63 M5 Waterpump Thermostat Connector Cylinder 1-5 7833988
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 8511747
Coolant Hose BMW F10 F11 LCI Radiator Cooling Water Pipe Line 8511747
PLN 94.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7612445
Cooling Hose BMW E84 N20 Petrol Engine Radiator Water Coolant Pipe Line 7612445
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 7592723-1
BMW F80 M3 F82 F83 M4 Thermostat Oil Transmission Cooler Hoses 7592723
PLN 427.95
Free delivery: Mar 20
If paid before 14:00
Part no. 9894757
BMW X3 G01 X4 G02 Coolant Cooling Pipe Hose Line B48 Petrol Engine 9894757
PLN 94.95
Free delivery: Mar 20
If paid before 14:00
Part no. 502017380
BMW F20 Petrol Auxiliary Water Coolant Pipe Pump 502017380
PLN 284.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8509741-1
BMW F01 F02 F10 F11 F12 Radiator Fan Housing Frame 600W 8509741
PLN 370.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 7565095
BMW E81 E87 E90 E91 E92 Hose Radiator Coolant Cooling Pipe Line Tube 7565095
PLN 123.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7555103
BMW X5 X6 E70 E71 Support Holder Bracket Engine Control Unit Box 7555103
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 7592646
Hose BMW F13 Coupe N63 Heat Exchanger Coolant Cooling Pipe Line 7592646
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 8581627-2
Thermostat Insert BMW G01 G02 G05 G20 G21 G30 G31 Housing Engine Cooling 8581627
PLN 66.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7834051
BMW 5 6 Series E60 M5 E63 M5 Waterpump Thermostat Connector Cylinder 6-10
PLN 42.95
Delivery: Mar 20 – 23
If paid before 14:00
Part no. 3424499
BMW X3 Series E83N LCI Radiator Bottom Coolant Water Hose 3424499
PLN 42.95
Delivery: Mar 20 – 23
If paid before 14:00
Part no. 7648827-2
Water Pump BMW F20 F30 N13 Mini R55 R56 N14 Mechanical Coolant Pump 7648827
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 7598496
Coolant Hose BMW F10 F11 F07GT Petrol N55 Thermostat Inlet Pipe 7598496
PLN 94.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8514218
Coolant Hose BMW X5 F15 X6 F16 Cylinder Head To Radiator Hose Line 8514218
PLN 74.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7846363
BMW F10 M5 F12 M6 Coolant Hose Radiator Cooling Water Pipe Connector 7846363
PLN 237.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7800408-1
BMW 3 5 Series E90 E91 LCI F10 F11 N57 Heat Exchanger Bracket Part 7800408
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 9119178
BMW F10 F11 F01 F02 N57 Diesel Return Hose Pipe Cooling Water 9119178
PLN 56.95
Delivery: Mar 20
If paid before 14:00
Part no. 7787440
BMW 5 Series E60 E61 Engine Cooling System Water Coolant Radiator Diesel 7787440
PLN 142.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 7604981
BMW 3 4 Series F30 F31 F32 Transmission Oil Cooler Line Flow Pipe 7604981
PLN 132.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7605432
BMW F01 LCI F12 F13 Coolant Hose Petrol N55 Thermostat Inlet Pipe 7605432
PLN 89.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8638494
BMW G30 G11 G12 F30 LCI Coolant Engine Water Pump 8638494
PLN 232.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7524841
BMW E65 E66 E67 Radiator Coolant Cooling Return Water Hose Pipe 7524841
PLN 142.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7823544-1
Radiator Expansion Tank BMW X3 F25 X4 F26 Overflow Tank Bottle 7823544
PLN 42.95
Delivery: Mar 20
If paid before 14:00
Part no. 9249616
Coolant Hose BMW X3 F25 X4 F26 Diesel Heater Water Return Pipe Line 9249616
PLN 47.95
Delivery: Mar 20
If paid before 14:00
Part no. 7019548
BMW 7 Series E65 E66 E67 Bracket Wash Water Container Top 7019548
PLN 47.95
Delivery: Mar 20
If paid before 14:00
Part no. 7559966
BMW X5 E53 Engine Cooling Radiator Thermostat 1439115
PLN 94.95
Free delivery: Mar 20
If paid before 14:00
Part no. 5A1D497
Water Hose BMW F70 F74 U06 U11 Engine Coolant Cooling Pipe Line 5A1D497
PLN 142.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8516205-1
BMW F10 F11 X3 F25 F30 F31 F32 Water Pump Engine Coolant Unit N57Z 8516205
PLN 56.95
Delivery: Mar 20
If paid before 14:00
Part no. 7555281
BMW X5 E70 3.0si N52N Engine Coolant Hose Cooling Pipe Line 7547244
PLN 218.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8053466
Coolant Hose BMW X3 F97 X4 F98 Water Charge Cooling Pipe 8053466
PLN 189.95
Free delivery: Mar 20
If paid before 14:00
Part no. 9329645
Water Hose BMW F20 F21 F30 LCI B48 Coolant Cooling Pipe Line 9329645
PLN 94.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7600511-1
Radiator BMW F20 F21 F30 F31 Engine Water Cooler Cooling Unit 7600511
PLN 113.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 6908340
BMW X5 Series E53 Webasto Auxiliary Heater Exhaust Pipe System 6908340
PLN 41.95
Delivery: Mar 20
If paid before 14:00
Part no. 7558480
BMW E82 E88 E90 E91 135i 335i Engine Radiator Coolant Cooler 7558480
PLN 284.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 7591094
BMW F01 F01 LCI F02 F02 LCI F03 F03 LCI Coolant Hose Tube Pipe Line 17127591094
PLN 61.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7608407
Fan Motor BMW F30 Radiator Fan Motore Radiator Cooling Fan 7608407
PLN 142.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8519112
BMW X5 F15 Diesel Engine Coolant Hose Line Tube Supply Return 8519112
PLN 75.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7541704
BMW Z4 Series E85 Intake Turbo Silencer Rubber Boot Hose Line 7541704
PLN 55.95
Delivery: Mar 20
If paid before 14:00
Part no. 7644099
BMW X5 F15 40eX N20 High Voltage Water Cooling Tube Pipe Line Hose 7644099
PLN 113.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8642732
Coolant Pump BMW F30 LCI Petrol B48X Turbo Cooling Auxiliary Pump 8642732
PLN 426.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8592808
Coolant Hose BMW G30 G31 G32 GT Diesel Transmission Oil Cooler Hose 8592808
PLN 113.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8514464
Water Pump Bracket BMW F10 F11 F15 F25 Holder Mount Auxiliary Radiator 8514464
PLN 66.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8642160
BMW F10 LCI Radiator Fan Motor Engine Cooling Coolant Unit 400W 8642160 8641950
PLN 379.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7581873
Coolant Line BMW F10 N52 N53 Petrol Water Pump Engine Coolant Feed Hose 7581873
PLN 156.95
Free delivery: Mar 20
If paid before 14:00
Part no. 7559273
BMW E87 E90 E91 E92 Complete Set Radiator Pack Fan Housing Automatic 7559273
PLN 1,424.95
Free delivery: Mar 20 – 23
If paid before 14:00
Part no. 2284880-1
BMW F06 F10 F12 Expansion Tank Radiator Coolant Overflow Fluid Bottle 2284280
PLN 113.95
Free delivery: Mar 20
If paid before 14:00
Part no. 2284880
Expansion Tank BMW F10 M5 Radiator Coolant Overflow Fluid Bottle F12 M6 2284280
PLN 113.95
Free delivery: Mar 20
If paid before 14:00
Part no. 8570079
BMW E81 E87 E90 E92 Expansion Tank Bottle Coolant Radiator Tank Diesel 8570079
Product currently unavailable
Part no. 7805310
BMW 1 3 X1 Series E81 E82 E87 E87N E88 E90 E90N E91 Rubber Mounting Radiator
Product currently unavailable
Part no. 7563259-2
BMW 1 3 Series e81 e87 e90 e91 e92 Complete Set Radiator Fan Housing With Fan 2
Product currently unavailable
Part no. 7788905-2
BMW E87 E90 Radiator Fan Housing Coolant Unit Diesel 7801993 7788905
Product currently unavailable
Part no. 7586925
BMW X5 E60 E61 E70 E81 E87 E90 E91 E92 Electric Coolant Water Pump 7586925
Product currently unavailable
Part no. 7801647-1
BMW E87 E90 Diesel Engine Cooling Radiator Fan Housing Motor 600W 7801647
Product currently unavailable
Part no. 7787458
BMW 5 6 Series E60 E61 E63 M57N Diesel Cooling Radiator Hose Water Pipe 7787458
Product currently unavailable
Part no. 8369807
Additional Water Pump BMW Z3 E36 E46 X3 E83 Heater Water Valve Regulator 8369807
Product currently unavailable
Part no. 7544550
BMW X3 F25 Engine Radiator Rubber Mount Bush Grommet X4 F26 7544550
Product currently unavailable
Part no. 7642160
BMW F20 F21 F30 F32 Radiator Expansion Tank Bottle 7642160
Product currently unavailable
Part no. 7794577
Oil Cooling Pipe BMW E60 E61 E63 E65 LCI Inlet and Outlet Hose 7794577
Product currently unavailable
Part no. 7644811
BMW F20 F21 F30 F31 LCI Thermostat Water Pump B38 B48 Petrol Engine 7644811
Product currently unavailable
Part no. 3403551
BMW X3 E83 Radiator Engine Water Cooling 17113403551 3403551
Product currently unavailable
Part no. 8514456
BMW F10 F20 F22 F30 F32 B47 Cylinder Head Coolant Hose Pipe Line 8514456
Product currently unavailable
Part no. 3403987
BMW X3 E83 E83N LCI Bracket Expansion Tank Bracket Support Mount 3403987
Product currently unavailable
Part no. 3414008-1
BMW X3 E83 Engine Cooling Radiator Rad Fan Motor Housing 400W 3414008
Product currently unavailable
Part no. 7640514-1
BMW E87 E90 E91 E92 Coolant Expansion Tank Bottle Petrol 7640514
Product currently unavailable
Part no. 7553111-1
BMW X1 E81 E87 E90 E91 E92 E93 LCI Coolant Radiator Petrol 7553111
Product currently unavailable
Part no. 8379979
BMW E65 E66 730d Engine Flow Auxiliary Water Pump Hose 8379979
Product currently unavailable
Part no. 7788906-2
BMW E81 E87 E90 Radiator Fan Housing 118d 120d 318d 320d Motor 400W 7788906
Product currently unavailable
Part no. 7553919-3
Coolant Level Sensor BMW E60 E61 E83 E87 E90 E91 7192724
Product currently unavailable
Part no. 6910755
BMW 5 6 Series E60 E61 E63 E64 Additional Auxiliary Water Pump 6910755
Product currently unavailable
Part no. 8616548
BMW F20 F21 F30 LCI Hose Engine Feed Radiator Top Pipe 8616548
Product currently unavailable
Part no. 2248058
BMW X5 Series E53 3.0d M57 Water Hose Pipe Engine Cooling 2248058
Product currently unavailable
Part no. 7542986
BMW E60 E61 E63 E64 LCI Cooling Water Expansion Tank Petrol 7521189
Product currently unavailable
Part no. 1712058
BMW E36 E46 X5 E53 Petrol Engine Cooling System Fan Viscous Blades
Product currently unavailable
Part no. 8687503
BMW X1 F48 F45 Mini F55 F56 F60 Expansion Tank Coolant Reservoir Bottle 8687503
Product currently unavailable
Part no. 7573781
BMW E46 X5 E53 X3 E83 Coolant Expansion Tank Radiator Header Reservoir 7573781
Product currently unavailable
Part no. 7500594
BMW 1 3 X3 Series E46 E81 E87 E90 E91 N45 N46 Coolant Cool Water Pump 7500594
Product currently unavailable
Engine cooling system parts – proven solutions for your car
Cooling components for BMW, Audi, Mercedes and others – guaranteed quality and fit
The engine cooling system is one of the most important systems in any vehicle, responsible for maintaining optimal operating temperature of the engine. It prevents engine overheating and protects against costly breakdowns. At Global Parts, you'll find a wide selection of used car parts. for cooling systems such as radiators, fans, water pumps, and thermostats. Our range of cooling systems is tailored to brands such as BMW , Audi , Volkswagen , Mercedes , Mini, and many others, so you'll find the perfect solution for your vehicle.
How does the engine cooling system work?
The engine cooling system is a complex system responsible for removing excess heat generated during engine operation. Its key components include:
-
- Fans and fan housings – They are responsible for air flow and radiator cooling.
- Cooling system hoses and lines – They transport the coolant between individual system components.
- Water coolers – Key elements responsible for collecting heat from the engine and dissipating it.
- Thermostats and housings – Regulate coolant flow, maintaining optimal engine temperature.
- Water pumps – They drive the circulation of coolant, enabling efficient engine cooling.
- Oil coolers and hoses – They help maintain optimal oil temperature, reducing oil degradation.
- Expansion tanks – They are responsible for maintaining the proper coolant level and compensating for changes in liquid volume.
- Overlays – Protective elements of the cooling system, increasing its durability.
- Clamps and mounting parts – They enable stable mounting of cooling system components.
- Fan blades – They support cooling by increasing airflow.
- Fan clutches – Regulates the fan speed depending on the engine temperature.
- Fan and blower motors – They are responsible for the operation of the fan, ensuring proper cooling.
- Temperature sensors – Monitor engine and coolant temperature, sending information to the controller. All of these components work together to keep the engine at a stable operating temperature, protecting it from overheating or overcooling.
Parameters of cooling systems in cars
The engine cooling system in a passenger car operates at temperatures ranging from 85°C to 105°C, depending on the vehicle model and manufacturer's specifications. Modern radiators are typically constructed of aluminum, which provides better thermal conductivity and lower weight. Coolant flow requires adequate pressure—typically between 0.9 and 1.5 bar —which is maintained by the reservoir cap. Proper operation of this system is crucial to maintaining engine efficiency.
Why is it worth taking care of the engine cooling system?
Regular maintenance and replacement of worn cooling system components is essential for long and reliable engine operation. A neglected system can lead to:
- Engine overheating, which increases the risk of serious damage.
- Coolant leaks that may reduce cooling efficiency.
- Higher repair costs resulting from failures caused by a faulty system. At Global Parts we offer genuine used car parts, which undergo detailed quality tests, ensuring their reliability.
The most common cooling system components and their roles:
| System element | Function | Typical symptoms of damage |
|---|---|---|
| Cooler | Heat removal from the fluid | Fluid leak, temperature rise |
| Water pump | Coolant circulation | Loud operation, engine overheating |
| Thermostat | Fluid flow regulation | Heating too slowly or overheating too quickly |
| Temperature sensor | Temperature monitoring | Incorrect readings, computer error |
| Fan | Forcing air flow | No cooling when stationary |
How to choose the right parts for your cooling system?
When deciding to purchase parts for the cooling system, it is worth paying attention to several key factors:
- Vehicle-specific fit – Every car make and model has its own technical specifications. At Global Parts, you'll find parts for BMW , Audi , Volkswagen , Mercedes , Mini, and many more.
- Technical condition – Used parts, such as radiators or water pumps, should be fully functional and ready for further use.
- Radiator type – Depending on your needs, you can choose standard, intercooler or radiators dedicated to sports vehicles.
Compatibility examples
When choosing cooling system parts, it's worth considering compatibility with other components. For example, a radiator for a BMW 3 Series (E46) can be fitted to several engine variants – both petrol and diesel – but the water pump will have different part numbers depending on the engine capacity. Similarly, the Audi A4 B8 uses several types of thermostats, varying in opening temperature range (from 87°C to 95°C ).
Why choose used cooling system parts?
Car parts for the cooling system is a solution that combines high quality with savings. Why is it worth considering?
- Lower costs – Used radiators, water pumps and thermostats are much cheaper than new ones, but offer just as high quality.
- Ecology – By choosing used car parts, you support recycling and reduce the amount of automotive waste.
- Wide range – We offer parts for the most popular car brands, so you can easily find the right components for your car.
How to take care of the engine cooling system?
To keep your cooling system running smoothly for a long time, it is worth remembering a few rules:
- Regularly check the coolant level and quality – contaminated or low coolant levels can lead to engine overheating.
- Check the condition of the radiator and pipes – leaks or damage may reduce cooling efficiency.
- Change the coolant according to the manufacturer's recommendations – this is the key to keeping the system in perfect condition. If you notice any problems, you'll find the right used car parts at Global Parts that will help restore your vehicle to full working order.
FAQ - Frequently asked questions about car engine cooling systems
| Question | Answer |
|---|---|
| What is the main purpose of the cooling system? | This is a system of components responsible for maintaining the operating temperature of the drive unit within the optimal range. |
| How does a car radiator work? | The radiator extracts heat from the coolant and releases it to the environment, assisted by a fan and air flow. |
| What does a thermostat do in a cooling system? | The thermostat regulates the moment when coolant begins to circulate through the radiator, allowing the engine to reach operating temperature faster. |
| How do you know if your water pump is faulty? | Symptoms include fluid leaks around the timing belt, unusual operating noises, and increased engine temperature. |
| Are cooling parts the same for all car models? | No – even within a single brand, there are differences in parameters and construction. Therefore, it's worth matching the part by its VIN or catalog number. |
| What are the symptoms of a damaged engine temperature sensor? | These may be incorrect readings on the dashboard, a problem with starting the fan or error messages in the on-board computer. |
| Are used coolers safe? | Yes – provided they have been tested for leaks and are free of mechanical damage. At Global Parts, every part undergoes quality control. |
Summary: Engine Cooling at the Global Parts Automotive Store
The engine cooling system is fundamental to the reliability of any vehicle. By ensuring its proper operation, you ensure your engine operates at optimal operating temperatures, extend its lifespan, and prevent costly breakdowns. The Global Parts automotive store invites you to browse our wide selection of genuine used car parts . Whether you're looking for car parts for BMW , Audi , Volkswagen , Mercedes, Mini , or more, you'll find them at competitive prices. We strive to ensure every customer finds the right parts for their car, and if you have any questions or concerns about selecting the right components, we're happy to help! Please contact us – we're here to help! For more information and interesting facts, visit our automotive blog .