Using vehicle speed sensors and seat sensors, smart airbags in the Civic deploy with different levels of force or don't deploy at all to help better protect passengers of all sizes in different collisions. The Civic's side airbags will shut off if a child is leaning against the door. The Mazda3's side airbags don't have smart features and will always deploy full force.

Both the Civic and the Mazda3 have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front and rear seatbelt pretensioners, front wheel drive, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, rearview cameras, driver alert monitors, available blind spot warning systems, rear parking sensors and rear cross-path warning.

The National Highway Traffic Safety Administration does 35 MPH front crash tests on new vehicles. In this test, results indicate that the Honda Civic is safer than the Mazda3:

New test not comparable to pre-2011 test results. More stars = Better. Lower test results = Better.

The National Highway Traffic Safety Administration does side impact tests on new vehicles. In this test, which crashes the vehicle into a flat barrier at 38.5 MPH and into a post at 20 MPH, results indicate that the Honda Civic is safer than the Mazda3:

New test not comparable to pre-2011 test results. More stars = Better. Lower test results = Better.

There are almost 2 times as many Honda dealers as there are Mazda dealers, which makes it much easier should you ever need service under the Civic's warranty.

J.D. Power and Associates' 2025 Initial Quality Study of new car owners surveyed provide the statistics that show that Honda vehicles are better in initial quality than Mazda vehicles. J.D. Power ranks Honda above average in initial quality. With 46 more problems per 100 vehicles, Mazda is rated below average.

From surveys of all its subscribers, Consumer Reports' March 2025 Auto Issue reports that Honda vehicles are more reliable than Mazda vehicles. Consumer Reports ranks Honda fourth in overall reliability. Mazda is ranked 6th.

The Civic Hybrid's standard 2.0 DOHC 4-cylinder hybrid produces 9 more horsepower (200 vs. 191) and 46 lbs.-ft. more torque (232 vs. 186) than the Mazda3's standard 2.5 DOHC 4-cylinder.

As tested in Motor Trend the Civic Hybrid 2.0 DOHC 4-cylinder hybrid is faster than the Mazda3 4 cyl. (automatics tested):

On the EPA test cycle the Civic Sedan gets better mileage than the Mazda3 Sedan:

On the EPA test cycle the Civic Sedan gets better mileage than the Mazda3 Hatchback:

On the EPA test cycle the Civic Hatchback gets better mileage than the Mazda3 Sedan:

On the EPA test cycle the Civic Hatchback gets better mileage than the Mazda3 Hatchback:

Regenerative brakes improve the Civic Hybrid's fuel efficiency by converting inertia back into energy instead of wasting it. The Mazda3 doesn't offer a regenerative braking system.

In heavy traffic or at stoplights the Civic's engine automatically turns off when the vehicle is stopped, saving fuel and reducing pollution. The engine is automatically restarted when the driver gets ready to move again. If the conditions warrant or the driver wishes, the system can be manually disabled at any time for the duration of a trip (not available Hybrid). The Mazda3 doesn't offer an automatic engine start/stop system.

To lower fuel costs and make buying fuel easier, the Honda Civic uses regular unleaded gasoline. The Mazda3 with the 2.5 turbo 4-cylinder engine requires premium for maximum efficiency, which can cost on average about 84.9 cents more per gallon.

The Civic has a standard cap-less fueling system. The fuel filler is automatically opened when the fuel nozzle is inserted and automatically closed when it's removed. This eliminates the need to unscrew and replace the cap and it reduces fuel evaporation, which causes pollution. The Mazda3 doesn't offer a cap-less fueling system.

In its Green Vehicle Guide, the U.S. Environmental Protection Agency (EPA) rates the Honda Civic higher (6 out of 10) than the Mazda3 (4 to 6). This means the Civic produces up to 12.1 pounds less smog-producing pollutants than the Mazda3 every 15,000 miles.

The Civic has a standard continuously variable transmission (CVT). With no “steps” between gears, it can keep the engine at the most efficient speed for fuel economy, or keep it at its peak horsepower indefinitely for maximum acceleration. The Mazda3 doesn't offer a CVT.

The Civic stops shorter than the Mazda3:

For better traction, the Civic has larger standard tires than the Mazda3 (215/55R16 vs. 205/60R16). The Civic Sport/Touring's tires are larger than the largest tires available on the Mazda3 (235/40R18 vs. 215/45R18).

The Civic LX Sedan's standard tires provide better handling because they have a lower 55 series profile (height to width ratio) that provides a stiffer sidewall than the Mazda3 2.5 S Sedan's standard 60 series tires. The Civic Sport/Touring's tires have a lower 40 series profile than the Mazda3 Select Sport/Preferred/Carbon/Premium's 45 series tires.

For superior ride and handling, the Honda Civic has fully independent front and rear suspensions. An independent suspension allows the wheels to follow the road at the best angle for gripping the pavement, without compromising ride comfort. The Mazda3 has a rear torsion beam axle, with a semi-independent rear suspension.

The Civic has standard front and rear stabilizer bars, which help keep the Civic flat and controlled during cornering. The Mazda3's suspension doesn't offer a rear stabilizer bar.

The Civic has vehicle speed sensitive variable-assist power steering, for low-effort parking, better control at highway speeds and during hard cornering, and a better feel of the road. The Mazda3 doesn't offer variable-assist power steering.

The Civic Sport Touring Hybrid Hatchback handles at .86 G's, while the Mazda3 Carbon Edition Sedan AWD pulls only .79 G's of cornering force in a Motor Trend skidpad test.

The Civic Sport Touring Hybrid Sedan executes Motor Trend's “Figure Eight” maneuver 1 seconds quicker than the Mazda3 Carbon Edition Sedan AWD (27.1 seconds @ .63 average G's vs. 28.1 seconds @ .58 average G's).

The Honda Civic may be more efficient, handle and accelerate better because it weighs about 100 to 200 pounds less than the Mazda3.

The Civic Hybrid uses computer-generated active noise cancellation to help remove annoying noise and vibration from the passenger compartment, especially at low frequencies. The Mazda3 doesn't offer active noise cancellation.

Because it has more passenger and cargo room, the EPA rates the Civic a Mid-size car, while the Mazda3 is rated a Compact.

The Civic has 6.2 cubic feet more passenger volume than the Mazda3 Sedan (99 vs. 92.8).

The Civic Sedan has 1.3 inches more front headroom, 1.3 inches more front shoulder room, 2.3 inches more rear legroom and 2.5 inches more rear shoulder room than the Mazda3 Sedan.

The Civic Sedan has a much larger trunk than the Mazda3 Sedan (14.8 vs. 13.2 cubic feet).

J.D. Power and Associates surveys of service recipients show that Honda service is better than Mazda. J.D. Power ranks Honda 7th in service department satisfaction (above the industry average). With a 5% lower rating, Mazda is ranked 10th.

Consumer Reports rated the Civic's headlight performance “Good,” a higher rating than the Mazda3's headlights, which were rated “Poor.”

Compared to traditional radio, the Honda Civic's standard SiriusXM satellite radio provides an unmatched listening experience. Its extensive coverage guarantees consistent, crystal-clear reception across the continental U.S., and access to over 100 channels dedicated to a multitude of genres, including music, news, sports, talk shows, and comedy, many with only limited commercial breaks. Satellite radio is only offered on the Mazda3 Premium/Turbo Premium Plus.

Consumer Reports® recommends both the Honda Civic and the Mazda3, based on reliability, safety and performance.

J.D. Power and Associates rated the Civic second among compact cars in owner reported satisfaction. This includes how well the vehicle performs and satisfies its owner's expectations. The Mazda3 isn't in the top three.

The Civic was chosen as a Car and Driver's “Top Ten” for 2025 and 10 more times in the last 41 years. The Mazda3 has never been chosen by Car and Driver in their “10Best” issue.

A group of representative automotive journalists from North America selected the Civic as the 2025 North American Car of the Year. The Mazda3 has never been chosen.

The Honda Civic outsold the Mazda3 by almost seven to one during 2024.