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2003 Chevrolet Trailblazer 4WD

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2003 Trailblazer 4WD.

Transmission Automatic 4-spd

The 2003 Chevrolet Trailblazer 4WD utilizes a 4-speed automatic transmission paired with an engine requiring 7.0 quarts of 5W-30 API oil to deliver an EPA-rated fuel economy of 20/23/21 mpg. Beyond these operational parameters, this model year occupies a notably problematic place in the vehicle's reliability history, burdened by 1,266 total owner complaints and 8 separate recalls. With the electrical system serving as the top complaint area, researchers should approach this specific iteration as a historically vulnerable point in the model's lineage where overall dependability is significantly compromised.

Quick specs

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

Engine oil capacity7.0 qtOEM · verified

Engine oil type5W-30 APIOEM · verified

Lug nut torque100 ft-lbsOEM · verified

EPA fuel economy20/23/21 mpgEPA · verified

Fitment & sizes

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

From the factory this vehicle uses a BCI 78 · 600 CCA battery, OE oil filter 12731179. Note the factory fuel filter is now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known.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 78 · 600 CCAOEM · verified

Tire sizeENVOY, TRAILBLAZER LS 4WD P245-70R16;BLAZER P235-75R15OEM · verified

Wheel / rim7-J, 7-J, 7-J inOEM · verified

OE service part numbers OEM · verified

Engine oil filter	12731179
Engine air filter	19239713
Fuel filter	19368932 discontinued
Spark plug	12681663
Battery	88866306 alt 88866121
Front wiper blades	15214346
Serpentine belt	12593774
Thermostat	12561155 alt 12620112

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

Transmission

Automatic 4-spd

Dimensions & weight NHTSA vPIC

Overall length	191.7 in
Overall width	74.4 in
Overall height	72 in
Wheelbase	113 in
Curb weight	4442 lb
Track (front / rear)	62.2 / 62.2 in
Weight distribution (front / rear)	54/46

Ratings & economy EPA / vPIC

EPA city / highway / combined	20 / 23 / 21 mpg
Drivetrain	4-Wheel or All-Wheel Drive
Recommended fuel	Regular Gasoline

Service quick specs OEM factory data

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

This engine holds 7.0 qt of 5W-30 API engine oil, 75W-90 · GL-5 in the differential. Torque lug nuts to 100 ft-lbs, the oil drain plug to 19.0 ft-lbs. The firing order is 1-5-3-6-2-4.

Lubricants & capacities

Differential Gear Oil	SYNTHETIC · 75W-90 · GL-5
Differential Gear Oil Capacity	3.6 qt
Differential Gear Oil	75W-90 · GL-5
Differential Gear Oil Capacity	4.3 qt
Engine Oil	5W-30 · API
Engine Oil Capacity	7.0 qt
Engine Oil	5W-30 · API
Engine Oil Capacity	7.0 qt

Engine torques

Engine Oil Pan Drain Plug	18.0 ft-lbs
Engine Oil Pan Drain Plug	19.0 ft-lbs
Engine Valve Cover Bolts	9.0 ft-lbs

Chassis torques

Lug Nuts

100 ft-lbs

Ignition

Cylinder Firing Order	1-5-3-6-2-4
Spark Plug Manufacturer	AC Delco
Spark Plug Type	AC 41-981
Spark Plug Gap	0.050 in
Spark Plug Torque	13.0 ft-lbs
Spark Plug Manufacturer	AC Delco
Spark Plug Type	AC 41-985
Spark Plug Gap	0.060 in

Battery & A/C

Refrigerant	R134a
Oil Group	PAG
Oil Type	46
Standard BCI Group Number	78
Standard BCI Cranking Performance	600 cca
Standard BCI Group Number	78
Standard BCI Cranking Performance	600 cca

Service checks

Pressure Test	15 psi
Radiator Cap Pressure Relief	15 psi
Thermostat Opening Temperature	188-206 °F
Pressure Test	15 psi
Radiator Cap Pressure Relief	15 psi
Thermostat Opening Temperature	188-206 °F
Fuel Pump Pressure Minimum	50.0 psi
Fuel Pump Pressure Maximum	57.0 psi

Brakes

Brake Application	WITH FOUR WHEEL DISC / WITH STANDARD
Torque to Knuckle	77 ft-lbs / 52 ft-lbs / 38 ft-lbs
Brake Application	WITH FOUR WHEEL DISC / WITH STANDARD
Torque to Knuckle	77 ft-lbs / 52 ft-lbs / 38 ft-lbs
Minimum Pad Thickness	Front: 0.030; Rear: 0.030 specification
Brake Application	WITH FOUR WHEEL DISC / WITH STANDARD
Rotor Max Parallel Variation	0.001 in
Rotor Runout Limit	0.002 in

Multi-step torque procedures OEM · verified

Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages

110 ft. lbs., step 2: 180

110 ft. lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the spark plugs every 100,000 mi; coolant at 150,000 mi. The big-interval services (at 150,000 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 7,500 mi	Axle Shaft Oil Seal (inspect) · CV Joint Boot (inspect) · Differential (inspect fluid level) · Tire & Wheel Assembly (rotate)
Every 30,000 mi	Engine Air Filter Element (replace) · Fuel Filter (replace)
Every 50,000 mi	Transfer Case Assembly (drain & refill)
Every 100,000 mi	PCV Valve (inspect) · Spark Plug Wires (inspect) · Spark Plugs (replace) · Transmission Fluid & Filter (replace)
At 150,000 mi	Accessory Drive Belt (inspect) · Engine Coolant System (drain, flush & refill)

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 2003 Chevrolet Trailblazer 4WD lead in one area — the electrical system, 295 of 1,266 reports (23%), well ahead of the next concern. None of this vehicle's 8 recall campaigns target the electrical system, so those reports read as owner-reported wear-and-tear rather than an acknowledged defect. 77 of the reports describe a crash and 21 a fire — a small share of the total, but worth weighing against the electrical system 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.

Open recalls

NHTSA campaigns

Service bulletins

Manufacturer communications

ODI investigations

Office of Defects Investigation

1,266

Owner complaints

77 involved a crash · 21 a fire

Owner complaints filed with NHTSA, by component

All 1,266 complaints on record, top 8 components.

Electrical System295

Fuel System, Gasoline175

Power Train98

Exterior Lighting63

Visibility61

Air Bags55

Fuel/Propulsion System54

Engine & Engine Cooling53

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 8 campaigns on record for this vehicle.

04V527000Exterior Lighting:Brake LightsReported 01/11/2004

ON CERTAIN SPORT UTILITY VEHICLES, VIBRATION AND HEAT MAY CAUSE THE TAIL LAMP/STOP LAMP BULB TO LOOSEN IN ITS SOCKET. IF THIS OCCURS, THE BULB MAY FLICKER AND EVENTUALLY BECOME INOPERATIVE. Remedy: DEALERS WILL INSPECT THE TAIL LAMP/STOP LAMP ASSEMBLIES, AND IF NECESSARY, REPLACE THEM. THE RECALL BEGAN ON NOVEMBER 22, 2004. OWNERS SHOULD CONTACT CHEVROLET AT 1-800-630-2438…

05V198000Exterior Lighting:Turn SignalReported 05/05/2005

ON CERTAIN TRUCKS AND SPORT UTILITY VEHICLES, THE DRIVER WISHING TO SIGNAL A TURN BY MOVING THE DIRECTIONAL SIGNAL LEVER, (UP OR DOWN) MAY CAUSE THE FRONT MARKER/TURN LIGHTS AND REAR TURN LIGHTS TO FLASH IN A MANNER… Remedy: DEALERS WILL REPLACE THE SUSPECT FLASHER MODULES WITH A NEW FLASHER MODULE DESIGNED WITH SEALED RELAYS AND MORE DURABLE CONTACT MATERIAL INSIDE OF THE RELAYS FREE OF CHARGE. THE…