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, 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.

Honda pays for scheduled maintenance on the Civic for 2 years and 24,000 miles. Honda will pay for oil changes, tire rotations, air filter replacements, cabin filter replacement, brake fluid replacement, inspections, and any other required maintenance. Mazda doesn't pay scheduled maintenance for the 3.

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' 2024 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 51 more problems per 100 vehicles, Mazda is rated below average.

From surveys of all its subscribers, Consumer Reports' January 2024 Auto Issue reports that Honda vehicles are more reliable than Mazda vehicles. Consumer Reports ranks Honda 2 places higher in reliability than Mazda.

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.

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

On the EPA test cycle the Civic 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.

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.

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'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 Sedan handles at .87 G's, while the Mazda3 Carbon Edition Sedan AWD pulls only .83 G's of cornering force in a Car and Driver skidpad test.

The Honda Civic may be more efficient, handle and accelerate better because it weighs about 150 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).

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

IntelliChoice estimates that five-year ownership costs (depreciation, financing, insurance, fuel, fees, repairs and maintenance) for the Honda Civic will be $375 to $5634 less than for the Mazda3.

The Civic was chosen as a Car and Driver's “Top Ten” for 2024 and 9 more times in the last 40 years. The Mazda3 has never been chosen by Car and Driver in their “10Best” issue.

The Honda Civic outsold the Mazda3 by almost seven to one during 2023.