For enhanced safety, the front and rear seat shoulder belts of the Mazda3 have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The MINI Cooper Hardtop 4 Door doesn't offer pretensioners for its rear seat belts.

For enhanced safety, the front seat shoulder belts of the Mazda3 are height-adjustable to accommodate a wide variety of driver and passenger heights. A better fit can prevent injuries and the increased comfort also encourages passengers to buckle up. The MINI Cooper Hardtop 4 Door doesn't offer height-adjustable seat belts.

The Mazda3 has standard Whiplash Reducing Headrests, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the Whiplash Reducing Headrests system moves the headrests forward to prevent neck and spine injuries. The Cooper Hardtop 4 Door doesn't offer a whiplash protection system.

The Mazda3 offers all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The Cooper Hardtop 4 Door doesn't offer all-wheel drive.

The Mazda3's standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. A lane departure warning system costs extra on the Cooper Hardtop 4 Door.

The Mazda3 has a standard blind spot warning system that uses sensors to alert the driver to objects in the vehicle's blind spots where the side view mirrors don't reveal them. A system to reveal vehicles in the Cooper Hardtop 4 Door's blind spot costs extra.

To help make backing out of a parking space safer, the Mazda3 has standard Rear Cross Traffic Alert and Rear Cross Traffic Braking on the Turbo Premium Plus automatically engages the brakes to help avoid a collision. MINI charges extra for Cross Traffic Warning on the Cooper Hardtop 4 Door.

Both the Mazda3 and the Cooper Hardtop 4 Door have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front wheel drive, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras, driver alert monitors and available around view monitors.

The Mazda3 Sedan has achieved the Insurance Institute for Highway Safety's (IIHS) highest rating of “Top Safety Pick Plus” for the 2025 model year. This distinction is based on its exceptional performance in IIHS' rigorous battery of safety tests. Specifically, it earned a “Good” rating in the latest, more stringent moderate overlap front crash test, a “Good” result in the updated side impact test, and a “Good” score in the revised pedestrian crash prevention test. The Cooper Hardtop 4 Door has not yet been evaluated by the IIHS for 2025.

Mazda's powertrain warranty covers the 3 1 year and 10,000 miles longer than MINI covers the Cooper Hardtop 4 Door. Any repair needed on the engine, transmission, axles, joints or driveshafts is fully covered for 5 years or 60,000 miles. Coverage on the Cooper Hardtop 4 Door ends after only 4 years or 50,000 miles.

There are over 5 times as many Mazda dealers as there are MINI dealers, which makes it much easier should you ever need service under the 3's warranty.

A reliable vehicle saves its owner time, money and trouble. Nobody wants to be stranded or have to be without a vehicle while it's being repaired. Consumer Reports rates the Mazda3's reliability 17 points higher than the Cooper Hardtop 4 Door.

J.D. Power and Associates' 2025 survey of the owners of three-year-old vehicles provides the statistics that show that Mazda vehicles are more reliable than MINI vehicles. J.D. Power ranks Mazda third in reliability, above the industry average. With 29 more problems per 100 vehicles, MINI is ranked 10th.

The Mazda3's standard 2.5 DOHC 4-cylinder produces 25 more horsepower (186 vs. 161) and 2 lbs.-ft. more torque (186 vs. 184) than the Cooper Hardtop 4 Door's standard 2.0 turbo 4-cylinder. The Mazda3's optional 2.5 turbo 4-cylinder produces 49 more horsepower (250 vs. 201) and 99 lbs.-ft. more torque (320 vs. 221) than the Cooper Hardtop 4 Door S' standard 2.0 turbo 4-cylinder.

An engine control system that can shut down some of the engine's cylinders helps improve the Mazda3 (except Turbo)'s fuel efficiency. The Cooper Hardtop 4 Door doesn't offer a system that can shut down part of the engine.

The Mazda3 AWD's standard fuel tank has 1.1 gallons more fuel capacity than the Cooper Hardtop 4 Door (12.7 vs. 11.6 gallons), for longer range between fill-ups. The Mazda3 FWD's standard fuel tank has 1.6 gallons more fuel capacity than the Cooper Hardtop 4 Door (13.2 vs. 11.6 gallons).

The Mazda3 has a standard space-saver spare tire so you can replace a flat tire and drive to have the flat repaired or replaced. A spare tire isn't available on the Cooper Hardtop 4 Door; it requires you to depend on roadside assistance and your vehicle will have to be towed.

For a smoother ride and more stable handling, the Mazda3's wheelbase is 6.2 inches longer than on the Cooper Hardtop 4 Door (107.3 inches vs. 101.1 inches).

For better handling and stability, the track (width between the wheels) on the Mazda3 is 2.7 inches wider in the front and 3.1 inches wider in the rear than on the Cooper Hardtop 4 Door.

The Mazda3 Sedan has .9 inches more front legroom, 1.8 inches more front hip room, 4.5 inches more front shoulder room, 2.8 inches more rear legroom and 3.7 inches more rear shoulder room than the Cooper Hardtop 4 Door.

To make loading and unloading groceries and cargo easier, especially for short adults, the Mazda3 Premium Hatchback has a standard power trunk, which opens and closes automatically by pressing a button. The Cooper Hardtop 4 Door doesn't offer a power liftgate.

The Cooper Hardtop 4 Door's cornering lamps activate a lamp on the front corner when the turn signal is activated. The Mazda3 Premium's standard adaptive cornering lights turn the actual headlight unit up to several degrees, depending on steering wheel angle and vehicle speed. This lights a significant distance into corners at any speed.

To shield the driver and front passenger's vision over a larger portion of the windshield and side windows, the Mazda3 has standard extendable sun visors. The Cooper Hardtop 4 Door doesn't offer extendable visors.

The Mazda3 Select Sport/Preferred/Carbon/Premium has a standard center folding armrest for the rear passengers. A center armrest helps make rear passengers more comfortable and it can provide a boundary between children. The Cooper Hardtop 4 Door doesn't offer a rear seat center armrest.

To keep a safe, consistent following distance, the Mazda3 has a standard Radar Cruise Control, which alters the speed of the vehicle without driver intervention. This allows the driver to use cruise control more safely without constantly having to disengage it when approaching slower traffic. The Cooper Hardtop 4 Door doesn't offer an adaptive cruise control.

Compared to the MINI Cooper Hardtop 4 Door, the Mazda3 eliminates the need for separate garage door openers and associated risks of losing, breaking, or having dead batteries with its optional integrated Homelink® universal remote controlled from the rear view mirror.

The Mazda3 has won recognition from these important consumer publications:

The Mazda3 outsold the MINI Cooper Hardtop 4 Door by almost 12 to one during 2024.