PlymouthConquest1986Overview/plymouth/conquest/1986/base/

1986 Plymouth Conquest

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1986 Conquest.

Transmission Automatic 4-spd

The 1986 Plymouth Conquest arrives as a technologically ambitious sport coupe pairing a 4-speed automatic transmission with EPA fuel economy ratings of 17 mpg city, 22 mpg highway, and 19 mpg combined — figures that reflect the performance-oriented tuning philosophy underpinning the model. Those mileage numbers, modest by any standard, tell researchers as much about the engine's character and the car's weight as any spec sheet could, situating the Conquest firmly in the grand-touring tradition where mechanical complexity takes priority over efficiency. Within the model's broader production history, the 1986 model year represents a midpoint where early-generation growing pains had largely been addressed but where the underlying powertrain and electronics architecture still demanded attentive maintenance, making surviving examples a study in how well owners understood and preserved the engineering rather than a testament to inherent long-term durability.

Model year198619851984

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

EPA fuel economy17/22/19 mpgEPA · verified

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic 4-spd

Ratings & economy EPA / vPIC

EPA city / highway / combined17 / 22 / 19 mpg
DrivetrainRear-Wheel Drive
Recommended fuelPremium Gasoline

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine GL-5 · 80W-90 · 85W-90 in the differential, DOT 3 brake fluid.

Lubricants & capacities

Brake FluidDOT 3
Differential Gear OilGL-5 · 80W-90 · 85W-90
Differential Gear Oil Capacity2.5 Pints
Engine CoolantETHYLENE GLYCOL
Power Steering FluidUSE MOPAR PART NO. 4318055 OR EQUIVALENT

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 3,000 mi; spark plugs every 30,000 mi; coolant every 30,000 mi. The big-interval services (every 30,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

Every 3,000 miEngine Oil (drain & refill)
Every 6,000 miEngine Oil Filter (replace)
Every 7,500 miClutch Master Cylinder (inspect fluid level) · Power Steering System (inspect)
At 15,000 miThrottle Position Sensor (inspect)
Every 15,000 miAccessory Drive Belt (inspect) · Air Conditioning System (inspect) · Brake System (inspect) · Drive Axle Assembly (drain & refill) · Engine Valves (inspect valve lash) · Exhaust System (Complete) (inspect)
Every 30,000 miAccessory Drive Belt (inspect) · Differential (inspect fluid level) · Engine Air Filter Element (replace) · Engine Coolant System (drain, flush & refill) · Spark Plugs (replace) · Steering Linkage (inspect)
Every 50,000 miAir Injection System (inspect) · Air Intake Duct (inspect) · Engine Coolant System Hoses (inspect) · Fuel Evaporative Canister (replace) · Fuel Evaporative Emission Control System (inspect) · Fuel Evaporative Emission Control System Lines (inspect)
At 60,000 miAccessory Drive Belt (inspect) · Air Conditioning System (inspect)
Every 60,000 miBrake Hydraulic System (drain, refill & bleed) · PCV System (inspect)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

1
Open recalls
NHTSA campaigns
0
Service bulletins
Manufacturer communications
0
ODI investigations
Office of Defects Investigation
0
Owner complaints
0 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Overall★★★★★
Frontal★★★★★
Side★★★★★
Rollover★★★★

No owner complaints on record with NHTSA for this vehicle.

Recalls NHTSA · verified

Showing 1 of 1 campaigns on record for this vehicle.

95V103003Seat Belts:Front:Buckle AssemblyReported 24/05/1995

THE FRONT SAFETY BELT BUCKLE RELEASE BUTTONS CAN BREAK. THESE RED PLASTIC RELEASE BUTTONS ARE MARKED "PRESS." IF A BUTTON BREAKS, PIECES CAN FALL INTO THE BUCKLE ASSEMBLY CAUSING THE BUCKLE TO OPERATE IMPROPERLY. Remedy: OWNERS SHOULD PROMPTLY CHECK THE CONDITION AND OPERATION OF BOTH FRONT SAFETY BELT BUCKLES AND CAREFULLY INSPECT THE RED RELEASE BUTTON FOR ANY BREAKS OR CRACKS. THEY SHOULD…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific Conquest. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Reference guides

Cross-vehicle references for the kinds of data on this page.

Frequently asked

Does the 1986 Conquest have open recalls?

NHTSA lists 1 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Conquest get?

EPA figures are 17 city / 22 highway / 19 combined mpg.