MazdaCX2021Overview/mazda/cx/2021/base/
30 platform

2021 Mazda CX

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2021 CX.

Transmission Automatic (S6)

The 2021 Mazda CX-30 rides on the 30 platform and pairs an automatic (S6) transmission with an EPA rating of 29/34/31 mpg, while routine maintenance specifies 4.8 quarts of 0W-20 oil. Within the model’s reliability history, this model year stands as a notably quiet entry, having generated only three owner complaints—with steering flagged as the top area of concern—and a single recall. For researchers, that sparse track record means the 2021 sample offers a limited but clearly defined set of reported issues to examine.

Model year2026202520242021

Quick specs

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

Engine oil capacity4.8 qtOEM · verified
Engine oil type0W-20OEM · verified
Lug nut torque80.0-108.0 ft-lbsOEM · verified
EPA fuel economy29/34/31 mpgEPA · verified

Fitment & sizes

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

From the factory this vehicle uses a BCI 47 · 520 CCA battery, OE oil filter 1WPE14302. 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 47 · 520 CCAOEM · verified
Tire size215/55R18 95HOEM · verified
Wheel / rim7 inOEM · verified

OE service part numbers OEM · verified

Engine oil filter1WPE14302 alt 1WPY14302
Engine air filterPAJ8133A0A
Fuel filterPA6A13ZE0 alt PA5W13ZE0
Spark plugPE5R18110A alt PY8V18110
BatteryPAF318520A9U
Front wiper bladesDGH967330 alt DGJ167330
Serpentine beltPX1315908 alt P30115908
ThermostatPY8V15171 alt PYFD1516ZA
Cabin air filterBDGF61J6X

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic (S6)

Dimensions & weight NHTSA vPIC

Overall length168.1 in
Overall width69.7 in
Overall height60.6 in
Wheelbase101.2 in
Curb weight2987 lb
Track (front / rear)59.8 / 59.8 in
Weight distribution (front / rear)60/40

Ratings & economy EPA / vPIC

EPA city / highway / combined29 / 34 / 31 mpg
DrivetrainFront-Wheel Drive
Recommended fuelRegular Gasoline

Service quick specs OEM factory data

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

This engine holds 4.8 qt of 0W-20 engine oil, Mazda Long Life Hypoid Gear Oil SG1 in the differential, DOT 3 brake fluid. Torque lug nuts to 80.0-108.0 ft-lbs, the oil drain plug to Use a new washer: 23.0-30.0 ft-lbs. The firing order is 1-3-4-2.

Lubricants & capacities

Automatic Transmission FluidATF
Automatic Transmission FluidATF
Brake FluidDOT 3
Brake FluidDOT 3
Differential Gear OilMazda Long Life Hypoid Gear Oil SG1
Differential Gear OilMazda Long Life Hypoid Gear Oil SG1
Engine CoolantMazda FL-22 Coolant
Engine Coolant Capacity8.7 qt

Engine torques

Engine Flywheel Bolts80.0-85.0 ft-lbs
Exhaust Manifold to Cylinder Head Bolts32.0-47.0 ft-lbs
Engine Oil Pan Drain PlugUse a new washer: 23.0-30.0 ft-lbs
Engine Oil Pan Drain PlugUse a new washer: 23.0-30.0 ft-lbs
Oil Pump to Cylinder BLock Bolts/Studs15.0-19.0 ft-lbs

Chassis torques

Differential Fill PlugFinal Drive: 30.0-39.0 ft-lbs
Differential Fill PlugFinal Drive: 30.0-39.0 ft-lbs
Lug Nuts80.0-108.0 ft-lbs
Transfer Case Fill PlugUse a new gasket: 30.0-42.0 ft-lbs
Transfer Case Drain PlugUse a new gasket: 30.0-42.0 ft-lbs
Transfer Case Fill PlugUse a new gasket: 30.0-42.0 ft-lbs
Transfer Case Drain PlugUse a new gasket: 30.0-42.0 ft-lbs

Ignition

Cylinder Firing Order1-3-4-2
Curb Idle Speed (No Load)Setting Speed: 700 rpm
Curb Idle Speed Variance (No Load)50 rpm
Curb Idle Speed (Secondary Under Load)Electrical or AC Speed-Up: 750 rpm
Curb Idle Speed Variance (Secondary Under Load)100 rpm
Curb Idle Speed (No Load)Setting Speed: 600 rpm
Curb Idle Speed Variance (No Load)50 rpm
Curb Idle Speed Variance (Secondary Under Load)75 rpm

Battery & A/C

Oil GroupPAG
Oil TypeR-134a: Pag 46; R-1234yf: Pag 46YF
Oil Capacity3.38 oz
Standard BCI Group Number47
Standard BCI Cranking Performance520 cca

Brakes

Brake Caliper Bolt to Carrier TorqueFront: 20.0-; Rear: 19.0-
Brake Caliper Carrier to Hub Bolt TorqueFront: 72.0 ft-lbs, Rear: NS
ABS Sensor Torque6.5
Minimum Pad Thickness0.079 in
Minimum Pad Thickness0.079 in
Vented Rotor Minimum Thickness for ReplacementFront: .906; Rear: .276
Vented Rotor Minimum Thickness after RefinishFront: .937; Rear: .307
Variation from Parallelism Thickness VariationFront: .0006; Rear: .0007

Multi-step torque procedures OEM · verified

Camshaft Bearing/Carrier Cap Bolts or Studs — tightening sequence 1 stages
127.0-53.0 inch lbs., Step 2: 71.0-97.0 inch lbs.27–53 in
Connecting Rod (Large End) Bearings — tightening sequence 1 stages
120.0-23.0 ft. lbs., Step 2: 80-100°20–23 ft. lbs
Connecting Rod (Large End) Bearings — tightening sequence 1 stages
120.0-23.0 ft. lbs., Step 2: 80-100°20–23 ft. lbs
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
167.0-81.0 ft. lbs., Step 2: 55-65°67–81 ft. lbs
Cylinder Head — tightening sequence 1 stages
19.5-12.5 ft. lbs., Step 2: 32.0-34.0 ft. lbs., Step 3: 85-95°, Step 4: 85-95°9.5–12.5 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 every 10,000 mi; spark plugs every 40,000 mi; coolant every 10,000 mi. The big-interval services (every 10,000 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 10,000 miAccessory Drive Belt (inspect) · Brake Hydraulic System (inspect fluid level) · Brake Linings (inspect) · Brake Rotor (inspect) · Engine Coolant System (inspect fluid level) · Engine Oil (drain & refill)
Every 30,000 miCabin Air Filter (replace)
Every 40,000 miSpark Plugs (replace)
At 120,000 miEngine Coolant System (drain, flush & refill)
At 180,000 miEngine 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 2021 Mazda CX dominate in one area — the steering, 3 of 3 reports (100%), well ahead of the next concern. None of this vehicle's 1 recall campaigns target the steering, so those reports read as owner-reported wear-and-tear rather than an acknowledged defect. 0 of the reports describe a crash and 0 a fire — a small share of the total, but worth weighing against the steering 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.

1
Open recalls
NHTSA campaigns
276
Service bulletins
Manufacturer communications
0
ODI investigations
Office of Defects Investigation
3
Owner complaints
0 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Overall★★★★★
Frontal★★★★★
Side★★★★★
Rollover★★★★

Owner complaints filed with NHTSA, by component

All 3 complaints on record, top 1 components.

Steering3

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 1 of 1 campaigns on record for this vehicle.

23V487000Back Over Prevention: Sensing System: CameraReported 14/07/2023

Mazda North American Operations (Mazda) is recalling certain 2014-2018 Mazda3 and 2016-2021 CX-3 vehicles. The rearview camera image may not display properly by showing a flickering or distorted image. Remedy: Dealers will inspect and replace the rearview camera, as necessary. In addition, dealers will install a wiring harness fastening seal. All repairs will be performed free of…

Technical service bulletins NHTSA · verified

Showing 5 of 276 bulletins on record with NHTSA.

BulletinDateComponentSummary
SA-041-262026-06-18Electrical SystemThis SA supersedes the previously issued SA(s) listed below. The changes are noted in…
09-019-262026-06-17Electrical SystemThis bulletin supersedes the previously issued bulletin(s) listed below. The changes are…
SA-027-26a2026-06-16Electrical SystemThis SA supersedes the previously issued bulletin(s) listed below. The changes are noted…
SA-031-262026-04-30StructureDESCRIPTION Some vehicles may require the replacement of a damaged VIN plate or vehicle…
SA-029-262026-04-21Power TrainThis Service Alert supersedes the previously issued SA listed below: The changes are…

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 CX. 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 2021 CX take?

4.8 qt of 0W-20, per the factory manual.

Does the 2021 CX have open recalls?

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

What gas mileage does the CX get?

EPA figures are 29 city / 34 highway / 31 combined mpg.