Valve Train Components for 2018 Audi TT RS Quattro
Categories
- Aero Ground Effects & Body Kits
- Brackets, Flanges & Hangers
- Bumper
- Bumper & Components - Front
- Bumper & Components - Rear
- Bushings
- Center Console
- Cluster & Switches
- Console
- Control Cables
- Cowl
- Dashboard
- Door & Components
- Doors
- Ducts
- Exterior Trim - Door
- Exterior Trim - Fender
- Exterior Trim - Hood
- Exterior Trim - Lift Gate
- Exterior Trim - Pillars
- Exterior Trim - Quarter Panel
- Fender & Components
- Fenders
- Floor
- Floor & Rails
- Frame
- Front Door
- Front Seat Components
- Gaskets & Sealing Systems
- Gate & Hardware
- Glass - Door
- Glass - Lift Gate
- Glass - Windshield
- Glass & Hardware
- Glass, Windows & Related Components
- Glove Box
- Grille
- Grille & Components
- Hardware, Fasteners & Fittings
- Hinge Pillar
- Hood
- Hood & Components
- Horns
- Information Labels
- Inner Structure
- Instrument Panel
- Instrument Panel Components
- Interior Trim
- Interior Trim - Door
- Interior Trim - Pillars
- Interior Trim - Quarter Panels
- Interior Trim - Rear Body
- Interior Trim - Rear Door
- Interior Trim - Roof
- Jack & Components
- Labels
- Liftgate
- Lock & Hardware
- Master Cylinder - Components On Dash Panel
- Mirrors
- Outside Mirrors
- Quarter Panel
- Quarter Panel & Components
- Radiator Support
- Rear Body
- Rear Floor & Rails
- Rear Seat Components
- Rocker Panel
- Roof
- Roof & Components
- Seat Belt
- Seats
- Sensors
- Side Body
- Sound System
- Splash Shields
- Spoiler
- Steering Wheel
- Structural Components & Rails
- Switches, Solenoids & Actuators
- Truck Box
- Trunk
- Trunk Lid & Compartment
- Under Cover & Splash Shields
- Uniside
- Universal
- Wiper & Washer Components
- ABS Components
- Anti-Lock Brakes
- Body Wiring Harness & Components
- Brackets, Flanges & Hangers
- Brake Components
- Brake Hydraulics
- Bushings
- Control Modules
- Disc Pads & Brake Shoes
- Drums & Rotors
- Front Brakes
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Hoses & Pipes
- Hydraulic System
- Parking Brake
- Rear Brakes
- Sensors
- Service Kits
- Switches, Solenoids & Actuators
- ABS Components
- Air Bag Components
- Air Bag System
- Alarm System
- Alternator
- Alternator/Generator & Related Components
- Antenna & Radio
- Anti-Theft Components
- Anti-Theft System
- Battery
- Battery & Related Components
- Body Wiring Harness & Components
- Brackets, Flanges & Hangers
- Communication System Components
- Control Modules
- Convertible Top
- Doors
- Electrical Components
- Electrical Connectors
- Flasher Units, Fuses, & Circuit Breakers
- Front Door
- Front Seat Belts
- Fuel Door
- Fuse & Relay
- Gaskets & Sealing Systems
- Glass, Windows & Related Components
- Hardware, Fasteners & Fittings
- Headlamp Components
- Heated Seats
- High Mounted Stop Lamp
- Horn
- Ignition Lock
- Ignition System
- Information Labels
- Instruments & Gauges
- Keyless Entry Components
- Lane Departure Warning
- Lighting - Exterior
- Lighting - Interior
- Lumbar Control Seats
- Mirrors
- Mobile Multi-Media
- Navigation System
- Parking Aid
- Power Outlets
- Power Seats
- Powertrain Control
- Rear Seat Belts
- Relays
- Ride Control Components
- Roll Bar Components
- Senders
- Sensors
- Side Marker Lamps
- Starter
- Starter & Related Components
- Switches
- Switches, Solenoids & Actuators
- Tail Lamps
- Tire Pressure Monitor Components
- Wipers
- Wiring Harness
- Bearings
- Brackets, Flanges & Hangers
- Control Modules
- Cylinder Block Components
- Engine
- Engine Parts
- Filters
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Mounts
- Oil Cooler
- Oil Pan
- Oil Pump
- Pumps
- Sensors
- Switches, Solenoids & Actuators
- Turbocharger
- Turbocharger & Components
- Valve & Timing Covers
- Valve Train Components
- Wire, Cable & Related Components
- A/C Accumulator/Receiver Drier
- A/C Clutch & Compressor
- A/C Condenser & Evaporator
- A/C Flow Restrictors
- Automatic Temperature Controls
- Blower Motor & Fan
- Brackets, Flanges & Hangers
- Condenser, Compressor & Lines
- Control Modules
- Controls
- Evaporator & Heater Components
- Filters
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Heater
- Hoses & Pipes
- HVAC Case
- Information Labels
- Motors, Core, Case & Related Components
- Sensors
- Switches & Sensors
- Switches, Solenoids & Actuators
- Temperature Controls & Related Components
- Wire, Cable & Related Components
- Axle & Differential
- Bearings
- Brackets, Flanges & Hangers
- Bushings
- Control Modules
- Drive Axles
- Drive Shaft
- Electrical Connectors
- Front Suspension
- Hardware, Fasteners & Fittings
- Rear Axle
- Rear Suspension
- Ride Control
- Shocks & Components
- Shocks & Struts
- Stabilizer Bar & Components
- Struts & Components
- Suspension Components
- Suspension Mounting
- Suspension, Springs & Related Components
- Wheels
- Aero Ground Effects & Body Kits
- Brackets, Flanges & Hangers
- Bumper
- Bumper & Components - Front
- Bumper & Components - Rear
- Bushings
- Center Console
- Cluster & Switches
- Console
- Control Cables
- Cowl
- Dashboard
- Door & Components
- Doors
- Ducts
- Exterior Trim - Door
- Exterior Trim - Fender
- Exterior Trim - Hood
- Exterior Trim - Lift Gate
- Exterior Trim - Pillars
- Exterior Trim - Quarter Panel
- Fender & Components
- Fenders
- Floor
- Floor & Rails
- Frame
- Front Door
- Front Seat Components
- Gaskets & Sealing Systems
- Gate & Hardware
- Glass - Door
- Glass - Lift Gate
- Glass - Windshield
- Glass & Hardware
- Glass, Windows & Related Components
- Glove Box
- Grille
- Grille & Components
- Hardware, Fasteners & Fittings
- Hinge Pillar
- Hood
- Hood & Components
- Horns
- Information Labels
- Inner Structure
- Instrument Panel
- Instrument Panel Components
- Interior Trim
- Interior Trim - Door
- Interior Trim - Pillars
- Interior Trim - Quarter Panels
- Interior Trim - Rear Body
- Interior Trim - Rear Door
- Interior Trim - Roof
- Jack & Components
- Labels
- Liftgate
- Lock & Hardware
- Master Cylinder - Components On Dash Panel
- Mirrors
- Outside Mirrors
- Quarter Panel
- Quarter Panel & Components
- Radiator Support
- Rear Body
- Rear Floor & Rails
- Rear Seat Components
- Rocker Panel
- Roof
- Roof & Components
- Seat Belt
- Seats
- Sensors
- Side Body
- Sound System
- Splash Shields
- Spoiler
- Steering Wheel
- Structural Components & Rails
- Switches, Solenoids & Actuators
- Truck Box
- Trunk
- Trunk Lid & Compartment
- Under Cover & Splash Shields
- Uniside
- Universal
- Wiper & Washer Components
- ABS Components
- Anti-Lock Brakes
- Body Wiring Harness & Components
- Brackets, Flanges & Hangers
- Brake Components
- Brake Hydraulics
- Bushings
- Control Modules
- Disc Pads & Brake Shoes
- Drums & Rotors
- Front Brakes
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Hoses & Pipes
- Hydraulic System
- Parking Brake
- Rear Brakes
- Sensors
- Service Kits
- Switches, Solenoids & Actuators
- ABS Components
- Air Bag Components
- Air Bag System
- Alarm System
- Alternator
- Alternator/Generator & Related Components
- Antenna & Radio
- Anti-Theft Components
- Anti-Theft System
- Battery
- Battery & Related Components
- Body Wiring Harness & Components
- Brackets, Flanges & Hangers
- Communication System Components
- Control Modules
- Convertible Top
- Doors
- Electrical Components
- Electrical Connectors
- Flasher Units, Fuses, & Circuit Breakers
- Front Door
- Front Seat Belts
- Fuel Door
- Fuse & Relay
- Gaskets & Sealing Systems
- Glass, Windows & Related Components
- Hardware, Fasteners & Fittings
- Headlamp Components
- Heated Seats
- High Mounted Stop Lamp
- Horn
- Ignition Lock
- Ignition System
- Information Labels
- Instruments & Gauges
- Keyless Entry Components
- Lane Departure Warning
- Lighting - Exterior
- Lighting - Interior
- Lumbar Control Seats
- Mirrors
- Mobile Multi-Media
- Navigation System
- Parking Aid
- Power Outlets
- Power Seats
- Powertrain Control
- Rear Seat Belts
- Relays
- Ride Control Components
- Roll Bar Components
- Senders
- Sensors
- Side Marker Lamps
- Starter
- Starter & Related Components
- Switches
- Switches, Solenoids & Actuators
- Tail Lamps
- Tire Pressure Monitor Components
- Wipers
- Wiring Harness
- Bearings
- Brackets, Flanges & Hangers
- Control Modules
- Cylinder Block Components
- Engine
- Engine Parts
- Filters
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Mounts
- Oil Cooler
- Oil Pan
- Oil Pump
- Pumps
- Sensors
- Switches, Solenoids & Actuators
- Turbocharger
- Turbocharger & Components
- Valve & Timing Covers
- Valve Train Components
- Wire, Cable & Related Components
- A/C Accumulator/Receiver Drier
- A/C Clutch & Compressor
- A/C Condenser & Evaporator
- A/C Flow Restrictors
- Automatic Temperature Controls
- Blower Motor & Fan
- Brackets, Flanges & Hangers
- Condenser, Compressor & Lines
- Control Modules
- Controls
- Evaporator & Heater Components
- Filters
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Heater
- Hoses & Pipes
- HVAC Case
- Information Labels
- Motors, Core, Case & Related Components
- Sensors
- Switches & Sensors
- Switches, Solenoids & Actuators
- Temperature Controls & Related Components
- Wire, Cable & Related Components
- Axle & Differential
- Bearings
- Brackets, Flanges & Hangers
- Bushings
- Control Modules
- Drive Axles
- Drive Shaft
- Electrical Connectors
- Front Suspension
- Hardware, Fasteners & Fittings
- Rear Axle
- Rear Suspension
- Ride Control
- Shocks & Components
- Shocks & Struts
- Stabilizer Bar & Components
- Struts & Components
- Suspension Components
- Suspension Mounting
- Suspension, Springs & Related Components
- Wheels
Browse Categories
Select category
- Aero Ground Effects & Body Kits
- Brackets, Flanges & Hangers
- Bumper
- Bumper & Components - Front
- Bumper & Components - Rear
- Bushings
- Center Console
- Cluster & Switches
- Console
- Control Cables
- Cowl
- Dashboard
- Door & Components
- Doors
- Ducts
- Exterior Trim - Door
- Exterior Trim - Fender
- Exterior Trim - Hood
- Exterior Trim - Lift Gate
- Exterior Trim - Pillars
- Exterior Trim - Quarter Panel
- Fender & Components
- Fenders
- Floor
- Floor & Rails
- Frame
- Front Door
- Front Seat Components
- Gaskets & Sealing Systems
- Gate & Hardware
- Glass - Door
- Glass - Lift Gate
- Glass - Windshield
- Glass & Hardware
- Glass, Windows & Related Components
- Glove Box
- Grille
- Grille & Components
- Hardware, Fasteners & Fittings
- Hinge Pillar
- Hood
- Hood & Components
- Horns
- Information Labels
- Inner Structure
- Instrument Panel
- Instrument Panel Components
- Interior Trim
- Interior Trim - Door
- Interior Trim - Pillars
- Interior Trim - Quarter Panels
- Interior Trim - Rear Body
- Interior Trim - Rear Door
- Interior Trim - Roof
- Jack & Components
- Labels
- Liftgate
- Lock & Hardware
- Master Cylinder - Components On Dash Panel
- Mirrors
- Outside Mirrors
- Quarter Panel
- Quarter Panel & Components
- Radiator Support
- Rear Body
- Rear Floor & Rails
- Rear Seat Components
- Rocker Panel
- Roof
- Roof & Components
- Seat Belt
- Seats
- Sensors
- Side Body
- Sound System
- Splash Shields
- Spoiler
- Steering Wheel
- Structural Components & Rails
- Switches, Solenoids & Actuators
- Truck Box
- Trunk
- Trunk Lid & Compartment
- Under Cover & Splash Shields
- Uniside
- Universal
- Wiper & Washer Components
- ABS Components
- Anti-Lock Brakes
- Body Wiring Harness & Components
- Brackets, Flanges & Hangers
- Brake Components
- Brake Hydraulics
- Bushings
- Control Modules
- Disc Pads & Brake Shoes
- Drums & Rotors
- Front Brakes
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Hoses & Pipes
- Hydraulic System
- Parking Brake
- Rear Brakes
- Sensors
- Service Kits
- Switches, Solenoids & Actuators
- ABS Components
- Air Bag Components
- Air Bag System
- Alarm System
- Alternator
- Alternator/Generator & Related Components
- Antenna & Radio
- Anti-Theft Components
- Anti-Theft System
- Battery
- Battery & Related Components
- Body Wiring Harness & Components
- Brackets, Flanges & Hangers
- Communication System Components
- Control Modules
- Convertible Top
- Doors
- Electrical Components
- Electrical Connectors
- Flasher Units, Fuses, & Circuit Breakers
- Front Door
- Front Seat Belts
- Fuel Door
- Fuse & Relay
- Gaskets & Sealing Systems
- Glass, Windows & Related Components
- Hardware, Fasteners & Fittings
- Headlamp Components
- Heated Seats
- High Mounted Stop Lamp
- Horn
- Ignition Lock
- Ignition System
- Information Labels
- Instruments & Gauges
- Keyless Entry Components
- Lane Departure Warning
- Lighting - Exterior
- Lighting - Interior
- Lumbar Control Seats
- Mirrors
- Mobile Multi-Media
- Navigation System
- Parking Aid
- Power Outlets
- Power Seats
- Powertrain Control
- Rear Seat Belts
- Relays
- Ride Control Components
- Roll Bar Components
- Senders
- Sensors
- Side Marker Lamps
- Starter
- Starter & Related Components
- Switches
- Switches, Solenoids & Actuators
- Tail Lamps
- Tire Pressure Monitor Components
- Wipers
- Wiring Harness
- Bearings
- Brackets, Flanges & Hangers
- Control Modules
- Cylinder Block Components
- Engine
- Engine Parts
- Filters
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Mounts
- Oil Cooler
- Oil Pan
- Oil Pump
- Pumps
- Sensors
- Switches, Solenoids & Actuators
- Turbocharger
- Turbocharger & Components
- Valve & Timing Covers
- Valve Train Components
- Wire, Cable & Related Components
- A/C Accumulator/Receiver Drier
- A/C Clutch & Compressor
- A/C Condenser & Evaporator
- A/C Flow Restrictors
- Automatic Temperature Controls
- Blower Motor & Fan
- Brackets, Flanges & Hangers
- Condenser, Compressor & Lines
- Control Modules
- Controls
- Evaporator & Heater Components
- Filters
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Heater
- Hoses & Pipes
- HVAC Case
- Information Labels
- Motors, Core, Case & Related Components
- Sensors
- Switches & Sensors
- Switches, Solenoids & Actuators
- Temperature Controls & Related Components
- Wire, Cable & Related Components
- Axle & Differential
- Bearings
- Brackets, Flanges & Hangers
- Bushings
- Control Modules
- Drive Axles
- Drive Shaft
- Electrical Connectors
- Front Suspension
- Hardware, Fasteners & Fittings
- Rear Axle
- Rear Suspension
- Ride Control
- Shocks & Components
- Shocks & Struts
- Stabilizer Bar & Components
- Struts & Components
- Suspension Components
- Suspension Mounting
- Suspension, Springs & Related Components
- Wheels
- Aero Ground Effects & Body Kits
- Brackets, Flanges & Hangers
- Bumper
- Bumper & Components - Front
- Bumper & Components - Rear
- Bushings
- Center Console
- Cluster & Switches
- Console
- Control Cables
- Cowl
- Dashboard
- Door & Components
- Doors
- Ducts
- Exterior Trim - Door
- Exterior Trim - Fender
- Exterior Trim - Hood
- Exterior Trim - Lift Gate
- Exterior Trim - Pillars
- Exterior Trim - Quarter Panel
- Fender & Components
- Fenders
- Floor
- Floor & Rails
- Frame
- Front Door
- Front Seat Components
- Gaskets & Sealing Systems
- Gate & Hardware
- Glass - Door
- Glass - Lift Gate
- Glass - Windshield
- Glass & Hardware
- Glass, Windows & Related Components
- Glove Box
- Grille
- Grille & Components
- Hardware, Fasteners & Fittings
- Hinge Pillar
- Hood
- Hood & Components
- Horns
- Information Labels
- Inner Structure
- Instrument Panel
- Instrument Panel Components
- Interior Trim
- Interior Trim - Door
- Interior Trim - Pillars
- Interior Trim - Quarter Panels
- Interior Trim - Rear Body
- Interior Trim - Rear Door
- Interior Trim - Roof
- Jack & Components
- Labels
- Liftgate
- Lock & Hardware
- Master Cylinder - Components On Dash Panel
- Mirrors
- Outside Mirrors
- Quarter Panel
- Quarter Panel & Components
- Radiator Support
- Rear Body
- Rear Floor & Rails
- Rear Seat Components
- Rocker Panel
- Roof
- Roof & Components
- Seat Belt
- Seats
- Sensors
- Side Body
- Sound System
- Splash Shields
- Spoiler
- Steering Wheel
- Structural Components & Rails
- Switches, Solenoids & Actuators
- Truck Box
- Trunk
- Trunk Lid & Compartment
- Under Cover & Splash Shields
- Uniside
- Universal
- Wiper & Washer Components
- ABS Components
- Anti-Lock Brakes
- Body Wiring Harness & Components
- Brackets, Flanges & Hangers
- Brake Components
- Brake Hydraulics
- Bushings
- Control Modules
- Disc Pads & Brake Shoes
- Drums & Rotors
- Front Brakes
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Hoses & Pipes
- Hydraulic System
- Parking Brake
- Rear Brakes
- Sensors
- Service Kits
- Switches, Solenoids & Actuators
- ABS Components
- Air Bag Components
- Air Bag System
- Alarm System
- Alternator
- Alternator/Generator & Related Components
- Antenna & Radio
- Anti-Theft Components
- Anti-Theft System
- Battery
- Battery & Related Components
- Body Wiring Harness & Components
- Brackets, Flanges & Hangers
- Communication System Components
- Control Modules
- Convertible Top
- Doors
- Electrical Components
- Electrical Connectors
- Flasher Units, Fuses, & Circuit Breakers
- Front Door
- Front Seat Belts
- Fuel Door
- Fuse & Relay
- Gaskets & Sealing Systems
- Glass, Windows & Related Components
- Hardware, Fasteners & Fittings
- Headlamp Components
- Heated Seats
- High Mounted Stop Lamp
- Horn
- Ignition Lock
- Ignition System
- Information Labels
- Instruments & Gauges
- Keyless Entry Components
- Lane Departure Warning
- Lighting - Exterior
- Lighting - Interior
- Lumbar Control Seats
- Mirrors
- Mobile Multi-Media
- Navigation System
- Parking Aid
- Power Outlets
- Power Seats
- Powertrain Control
- Rear Seat Belts
- Relays
- Ride Control Components
- Roll Bar Components
- Senders
- Sensors
- Side Marker Lamps
- Starter
- Starter & Related Components
- Switches
- Switches, Solenoids & Actuators
- Tail Lamps
- Tire Pressure Monitor Components
- Wipers
- Wiring Harness
- Bearings
- Brackets, Flanges & Hangers
- Control Modules
- Cylinder Block Components
- Engine
- Engine Parts
- Filters
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Mounts
- Oil Cooler
- Oil Pan
- Oil Pump
- Pumps
- Sensors
- Switches, Solenoids & Actuators
- Turbocharger
- Turbocharger & Components
- Valve & Timing Covers
- Valve Train Components
- Wire, Cable & Related Components
- A/C Accumulator/Receiver Drier
- A/C Clutch & Compressor
- A/C Condenser & Evaporator
- A/C Flow Restrictors
- Automatic Temperature Controls
- Blower Motor & Fan
- Brackets, Flanges & Hangers
- Condenser, Compressor & Lines
- Control Modules
- Controls
- Evaporator & Heater Components
- Filters
- Gaskets & Sealing Systems
- Hardware, Fasteners & Fittings
- Heater
- Hoses & Pipes
- HVAC Case
- Information Labels
- Motors, Core, Case & Related Components
- Sensors
- Switches & Sensors
- Switches, Solenoids & Actuators
- Temperature Controls & Related Components
- Wire, Cable & Related Components
- Axle & Differential
- Bearings
- Brackets, Flanges & Hangers
- Bushings
- Control Modules
- Drive Axles
- Drive Shaft
- Electrical Connectors
- Front Suspension
- Hardware, Fasteners & Fittings
- Rear Axle
- Rear Suspension
- Ride Control
- Shocks & Components
- Shocks & Struts
- Stabilizer Bar & Components
- Struts & Components
- Suspension Components
- Suspension Mounting
- Suspension, Springs & Related Components
- Wheels
Valve Train Components for 2018 Audi TT RS Quattro
Related Parts
Part # / Description / Price
Price
Exhaust Valve 
Audi
Audi Description: RS3. TTS Quattro. From 01/25/18. TT RS Quattro. From 01/25/2018. To 01/23/2023. To 01/31/2023.
MSRP $114.82
$80.60
MSRP $114.82
$80.60
MSRP $3,219.56
$2,501.60
Engine Timing Camshaft Sprocket Audi
Audi Description: TT RS Quattro. Intake. RS3. To 10/19/2020.
MSRP $746.67
$515.20
MSRP $746.67
$515.20
Engine Timing Camshaft Sprocket Audi
Audi Description: TT RS Quattro. Exhaust. RS3. From 10/19/2020.
MSRP $784.45
$565.98
MSRP $784.45
$565.98
MSRP $273.33
$191.88
Engine Timing Cover Audi
Audi Positions: Lower
Description: TT RS Quattro. RS3. Lower. From 02/02/2019. To 02/02/2019.
MSRP $945.52
$682.19
MSRP $945.52
$682.19
Engine Timing Chain Tensioner Audi
Audi Description: Idler to Cam. Adjuster. RS3. To 06/05/2023.
MSRP $133.34
$93.60
MSRP $133.34
$93.60
MSRP $288.33
$202.41
Cover Audi
Audi Positions: Upper
Description: 2.5L. TT RS Quattro. RS3. Upper. To 02/02/2019.
MSRP $437.49
$301.86
MSRP $437.49
$301.86
MSRP $85.00
$59.67
MSRP $85.00
$59.67
Engine Timing Chain Tensioner Audi
Audi Description: Crank to Idler. TT RS Quattro. Secondary. RS3. From 06/05/2023.
Engine Timing Chain Guide Audi
Audi Positions: Lower
Description: Crank to Idler. RS3. Left.
MSRP $25.38
$16.75
MSRP $25.38
$16.75
Engine Timing Chain Tensioner Audi
Audi Description: Idler to Cam. Arm. TT RS Quattro. Primary. RS3. Left.
MSRP $131.67
$92.43
MSRP $131.67
$92.43
Guide Audi
Audi Positions: Upper
Description: Crank to Idler. TT RS Quattro. Secondary. RS3. Right.
MSRP $57.38
$34.71
MSRP $57.38
$34.71
MSRP $64.99
$47.18