AudiA6/Quattro1998Overview/audi/a6-quattro/1998/base/

1998 Audi A6/Quattro

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1998 A6/Quattro.

Transmission Automatic 5-spd

The 1998 Audi A6/Quattro sits on a compact‑cabin platform powered by a 6.3‑quart engine oil capacity and selectable oil viscosities of 5W‑30, 5W‑40, or 10W‑30, all of which feed its automatic five‑speed transmission; the EPA rates it at 15/24/18 mpg city/highway/mixed. This model year delivers a balanced blend of quattro all‑wheel‑drive handling and the standard automatic gearbox, while the fuel system remains the most cited area of owner concern, accounting for 134 complaints and prompting ten recalls. As a result, the 1998 A6/Quattro occupies a mid‑range spot in Audi’s reliability history, indicating a generally dependable chassis that nonetheless demands vigilant maintenance of its fuel delivery components.

Model year202520242023202220212020200520001998

Quick specs

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

Engine oil capacity6.3 qtOEM · verified
Engine oil type5W-30 / 5W-40 / 10W-30OEM · verified
Lug nut torque98 ft-lbsOEM · verified
EPA fuel economy15/24/18 mpgEPA · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 41 · 650 CCA battery, OE oil filter 078115561J. Note the factory serpentine belt, thermostat and cabin air filter are now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 41 · 650 CCAOEM · verified
Tail / brake / turn15AOEM · verified
Tire size195-65HR15OEM · verified
Wheel / rim7-J inOEM · verified

OE service part numbers OEM · verified

Engine oil filter078115561J
Engine air filter058133843
Fuel filter1H0201511A
Spark plug101000035HJ alt 101000051AA
Front wiper blades4A0955425B alt 4A0955425A
Serpentine belt078903137BC discontinued
Thermostat078121113F discontinued
Cabin air filter4B0819439A discontinued

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic 5-spd

Ratings & economy EPA / vPIC

EPA city / highway / combined15 / 24 / 18 mpg
Drivetrain4-Wheel or All-Wheel Drive
Passenger volume98 cu ft
Cargo volume15 cu ft
Recommended fuelPremium Gasoline

Service quick specs OEM factory data

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

This engine holds 6.3 qt of 5W-30 / 5W-40 / 10W-30 engine oil, Rear: 90 GL- in the differential, DOT 4 brake fluid. Torque lug nuts to 98 ft-lbs, the oil drain plug to 30.0 ft-lbs. The firing order is 1-4-3-6-2-5.

Lubricants & capacities

Brake FluidDOT 4
Differential Gear Oil Capacity1.7 Pints
Differential Gear OilRear: 90 GL-
Differential Gear Oil Capacity3.2 Pints
Engine Oil5W-30 · 5W-40 · 10W-30 · 10W-40 · 5W-50 · 10W-50 · 10W-60
Engine Oil Capacity6.3 qt
Engine Oil Capacity6.3 qt
Power Steering FluidUSE VW. PART NO. G002000

Engine torques

Camshaft Bearing/Carrier Cap Bolts or Studs7 ft-lbs
Intake Manifold to Engine Bolts15 ft-lbs
Exhaust Manifold to Cylinder Head Bolts7 ft-lbs
Intake Manifold to Engine Bolts7 ft-lbs
Exhaust Manifold to Cylinder Head Bolts18 ft-lbs
Engine Oil Pan Drain Plug30.0 ft-lbs
Oil Pump to Cylinder BLock Bolts/Studs18 ft-lbs
Engine Valve Cover Bolts7.2

Chassis torques

Lug Nuts98 ft-lbs
Transfer Case Fill Plug30.0 ft-lbs
Transfer Case Drain Plug30.0 ft-lbs
Rear Wheel Hub148 ft-lbs

Ignition

Cylinder Firing Order1-4-3-6-2-5
Curb Idle Speed (No Load)700 rpm
Curb Idle Speed Variance (No Load)50 rpm
Ignition Coil Secondary Resistance18,000-25,000 ohms
Spark Plug ManufacturerVW
Spark Plug Gap0.035-0.043 in
Spark Plug Torque22.0 ft-lbs
Spark Plug ManufacturerVW

Battery & A/C

RefrigerantR134a
Oil GroupPAG
Standard BCI Group Number41
Standard BCI Cranking Performance650 cca
Standard BCI Group Number41
Standard BCI Cranking Performance650 cca

Service checks

Pressure Test14.5 psi
Radiator Cap Pressure Relief17-22 psi
Thermostat Opening Temperature179 °F
Pressure Test14.5 psi
Radiator Cap Pressure Relief20-23 psi
Thermostat Opening Temperature188 °F
Regulated Fuel System Pressure (Without Vacuum)55.0-61.0 psi
Regulated Fuel System Pressure (With Vacuum)48.0-54.0 psi

Brakes

Torque to Knuckle89 ft-lbs / 95 ft-lbs
Torque Caliper to Bracket26 ft-lbs / 18 ft-lbs
Torque to Knuckle89 ft-lbs / 95 ft-lbs
Torque Caliper to Bracket26 ft-lbs / 18 ft-lbs
Rotor Nominal Thickness From1.181 in / 0.394 in / 0.984 in / 0.866 in
Rotor Nominal Thickness To1.181 in / 0.394 in / 0.984 in / 0.866 in
Rotor Discard at or Under1.102 in / 0.315 in / 0.906 in / 0.787 in
Rotor Nominal Thickness From1.181 in / 0.394 in / 0.984 in / 0.866 in

Multi-step torque procedures OEM · verified

Connecting Rod (Large End) Bearings — tightening sequence 1 stages
122 ft. lbs., Step 2: 9022 ft. lbs
Flex or Driveplate Bolts — tightening sequence 1 stages
144 ft. lbs., Step 2: 9044 ft. lbs
Engine Flywheel Bolts — tightening sequence 1 stages
130 ft. lbs., Step 2: 18030 ft. lbs
Main Bearings — tightening sequence 1 stages
144 ft. lbs., Step 2: 18044 ft. lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter at 5,000 mi; spark plugs every 30,000 mi; coolant at 7,500 mi. The big-interval services (at 7,500 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.

At 5,000 miEngine Oil (drain & refill)
At 7,500 miAir Conditioning Evaporator Case Drain (inspect) · Brake Hydraulic System (inspect fluid level) · Brake Shift Interlock Solenoid (inspect) · Engine Coolant System (leak inspection) · Engine Oil Filter (replace) · Neutral Safety Switch (test)
Every 7,500 miBrake Shift Interlock Solenoid (inspect) · Engine Oil (drain & refill)
Every 10,000 miEngine Oil (drain & refill) · Headlamp (inspect alignment)
Every 15,000 miAir Conditioning Evaporator Case Drain (inspect) · Axle Shaft Oil Seal (inspect) · Battery (inspect electrolyte level) · Brake Hydraulic System (inspect fluid level) · Brake Shift Interlock Solenoid (inspect) · Brake System (inspect)
At 30,000 miEngine Oil (drain & refill) · Engine Oil Filter (replace)
Every 30,000 miEngine Air Filter Element (replace) · Power Steering System (inspect) · Spark Plugs (replace) · Suspension System (inspect)
Every 90,000 miAccessory Drive Belt (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.

Owner complaints about the 1998 Audi A6/Quattro lead in one area — the fuel system, gasoline, 29 of 134 reports (22%), well ahead of the next concern. None of this vehicle's 10 recall campaigns target the fuel system, gasoline, so those reports read as owner-reported wear-and-tear rather than an acknowledged defect. 7 of the reports describe a crash and 7 a fire — a small share of the total, but worth weighing against the fuel system, gasoline pattern above. These are tallies of what owners actually reported to the federal government, not an editorial score — and higher-selling models naturally rack up more reports.

10
Open recalls
NHTSA campaigns
44
Service bulletins
Manufacturer communications
6
ODI investigations
Office of Defects Investigation
134
Owner complaints
7 involved a crash · 7 a fire

Owner complaints filed with NHTSA, by component

All 134 complaints on record, top 8 components.

Fuel System, Gasoline29
Service Brakes, Hydraulic16
Vehicle Speed Control15
Suspension10
Steering8
Structure8
Electrical System6
Engine & Engine Cooling4

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 10 campaigns on record for this vehicle.

20V056000Air Bags:Frontal:Driver Side:Inflator ModuleReported 31/01/2020

Volkswagen Group of America, Inc. (VW) is recalling certain 2000-2001 TT Roadster, 2000 TT Coupe, 1999 Audi A8, 1998-2000 Audi A6, and 1999-2000 Audi A4 vehicles equipped with Non-Azide Driver air bag Inflators (NADI)… Remedy: Dealers will replace the driver frontal air bag inflator with an alternative inflator when the parts become available, free of charge. Owner notifications were mailed September…

06V198000Electrical SystemReported 05/06/2006

ON CERTAIN PASSENGER VEHICLES EQUIPPED WITH HALOGEN LOW BEAM HEADLIGHTS, CERTAIN CONNECTOR PINS IN THE HEADLIGHT SWITCH CONNECTOR COME INTO CONTACT WITH EACH OTHER CAUSING A SHORT CIRCUIT. NOTE: VEHICLES WITH XENON LOW… Remedy: DEALERS WILL REROUTE THE WIRING HARNESS BY INSTALLING A JUMPER WIRING HARNESS. THE RECALL BEGAN ON DECEMBER 16, 2006. OWNERS MAY CONTACT AUDI AT 1-800-822-2834.

Technical service bulletins NHTSA · verified

Showing 5 of 44 bulletins on record with NHTSA.

BulletinDateComponentSummary
A451510 2042048-2015-10-05Power TrainVehicle will not communicate with diagnostic scan tool or emissions test equipment…
1310201828842013-09-05Back Over PreventionIf the vehicle?s engine experienced a serious mechanical problem, it is possible that…
1341202530332013-06-20Engine And Engine CoolingDiscontinuation and mixing of Audi-approved engine coolants.
1335202530322013-04-25Engine And Engine CoolingDiscontinuation and mixing of Audi-approved engine coolants.
TSB-24-11-662011-02-14Engine And Engine CoolingAUDI: IN COLD TEMPERATURES, ICE CAN ACCUMULATE ON THE THROTTLE BODY MAKING THE VEHICLE…

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 A6/Quattro. 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.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Reference guides

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

Frequently asked

How much oil does the 1998 A6/Quattro take?

6.3 qt of ENERGY CONSERVING OILS: 5W-30, 5W-40, 10W-30 OR 10W-40 MEETING VW SPECIFICATION VW50200, EXCEPT ENGERGY CONSERVING OILS: 5W-50, 10W-50, OR 10W-60 MEETING VW SPECIFICATION VW50200, per the factory manual.

Does the 1998 A6/Quattro have open recalls?

NHTSA lists 10 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the A6/Quattro get?

EPA figures are 15 city / 24 highway / 18 combined mpg.