2020 BMW Z4 vs. 2019 MINI Cooper Convertible

Detailed Review, Specifications & Comparison

Your buying experience includes...

business_centerProfessional Staff
account_balanceSimple Financing
local_gas_stationFull Tank of Gas
local_car_washFree Car Wash


The Z4’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Cooper Convertible doesn’t offer pre-crash pretensioners.

The Z4 has standard Post-Crash Braking, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Cooper Convertible doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.

The Z4’s optional lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane. The Cooper Convertible doesn’t offer a lane departure warning system.

The Z4’s optional blind spot warning system uses digital cameras monitored by computer to alert the driver to moving objects in the vehicle’s blind spots where the side view mirrors don’t reveal them. The Cooper Convertible doesn’t offer a system to reveal objects in the driver’s blind spots.

To help make backing safer, the Z4’s optional cross-path warning system uses wide-angle radar in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The Cooper Convertible doesn’t offer a cross-path warning system.

The Z4’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The Cooper Convertible doesn’t offer a driver alert monitor.

The Z4 has standard BMW Assist, which uses a global positioning satellite (GPS) receiver and a cellular system to remotely unlock your doors if you lock your keys in, help track down your vehicle if it’s stolen or send emergency personnel to the scene if any airbags deploy. The Cooper Convertible doesn’t offer a GPS response system, only a navigation computer with no live response for emergencies, so if you’re involved in an accident and you’re incapacitated help may not come as quickly.

Both the Z4 and the Cooper Convertible have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, rearview cameras and available rear parking sensors.


There are almost 3 times as many BMW dealers as there are MINI dealers, which makes it much easier should you ever need service under the Z4’s warranty.


The battery on the Z4 is in the trunk, which protects it from hot underhood temperatures that can degrade battery life. By keeping the Z4’s battery 20 to 30 degrees cooler, its life is increased by years. The Cooper Convertible’s battery is in the hot engine compartment.

J.D. Power and Associates’ 2019 Initial Quality Study of new car owners surveyed provide the statistics that show that BMW vehicles are better in initial quality than MINI vehicles. J.D. Power ranks BMW 20th in initial quality. With 5 more problems per 100 vehicles, MINI is ranked 23rd.

From surveys of all its subscribers, Consumer Reports’ December 2018 Auto Issue reports that BMW vehicles are more reliable than MINI vehicles. Consumer Reports ranks BMW 1 place higher in reliability than MINI.


The Z4 has more powerful engines than the Cooper Convertible:



Z4 sDrive30i 2.0 turbo 4-cyl.

255 HP

295 lbs.-ft.

Z4 M40i 3.0 turbo 6-cyl.

382 HP

368 lbs.-ft.

Cooper Convertible 1.5 turbo 3-cyl.

134 HP

162 lbs.-ft.

Cooper Convertible S 2.0 turbo 4-cyl.

189 HP

207 lbs.-ft.

John Cooper Works Convertible 2.0 turbo 4-cyl.

228 HP

236 lbs.-ft.

As tested in Car and Driver the Z4 sDrive30i is faster than the MINI Cooper Convertible (base engine) (automatics tested):



Zero to 30 MPH

1.9 sec

2.5 sec

Zero to 60 MPH

5.1 sec

7.5 sec

Zero to 100 MPH

13.2 sec

24.6 sec

5 to 60 MPH Rolling Start

6.1 sec

9.1 sec

Passing 30 to 50 MPH

3.3 sec

4.4 sec

Passing 50 to 70 MPH

3.8 sec

5.4 sec

Quarter Mile

13.8 sec

16 sec

Speed in 1/4 Mile

102 MPH

85 MPH

Top Speed

155 MPH

124 MPH

Fuel Economy and Range

The Z4 has 2.1 gallons more fuel capacity than the Cooper Convertible (13.7 vs. 11.6 gallons), for longer range between fill-ups.


The BMW Z4 comes standard with an automatic transmission, for driver comfort, especially in the city. Automatic costs extra on the Cooper Convertible.

An eight-speed automatic is standard on the BMW Z4, for better acceleration and lower engine speed on the highway. Only a six-speed automatic is available for the Cooper Convertible.

Brakes and Stopping

For better stopping power the Z4’s brake rotors are larger than those on the Cooper Convertible:

Z4 sDrive30i

Z4 M40i


John Cooper Works

Front Rotors

13 inches

13.7 inches

11 inches

13.2 inches

Rear Rotors

13 inches

13.6 inches

10.2 inches

10.2 inches

The Z4’s standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs on the Cooper Convertible are solid, not vented.

The Z4 stops much shorter than the Cooper Convertible:



70 to 0 MPH

146 feet

163 feet

Car and Driver

Tires and Wheels

For better traction, the Z4 has larger standard tires than the Cooper Convertible (F:225/45R18 & R:255/40R18 vs. 175/65R15). The Z4’s optional tires are larger than the largest tires available on the Cooper Convertible (F:255/35R19 & R:275/35R19 vs. 205/40R18).

The Z4’s standard 225/45R18 front and 255/40R18 rear tires provide better handling because they have a lower 45 series front and 40 series rear profile (height to width ratio) that provides a stiffer sidewall than the Cooper Convertible’s standard 65 series tires. The Z4’s optional tires have a lower 35 series profile than the Cooper Convertible’s optional 40 series tires.

For better ride, handling and brake cooling the Z4 has standard 18-inch wheels. Smaller 15-inch wheels are standard on the Cooper Convertible. The Z4’s optional 19-inch wheels are larger than the 18-inch wheels optional on the Cooper Convertible.

Suspension and Handling

For better handling and stability, the average track (width between the wheels) on the Z4 is 4.6 inches wider in the front and 4.4 inches wider in the rear than the average track on the Cooper Convertible.

The Z4’s front to rear weight distribution is more even (49.9% to 50.1%) than the Cooper Convertible’s (60.6% to 39.4%). This gives the Z4 more stable handling and braking.

The Z4 sDrive30i handles at 1.00 G’s, while the Cooper Convertible pulls only .84 G’s of cornering force in a Car and Driver skidpad test.


As tested by Car and Driver while cruising at 70 MPH, the interior of the Z4 sDrive30i is quieter than the Cooper Convertible S (70 vs. 71 dB).

Passenger Space

The Z4 has .8 inches more front legroom and 3.3 inches more front shoulder room than the Cooper Convertible.

Cargo Capacity

The Z4 has a much larger trunk than the Cooper Convertible with its top down (9.9 vs. 5.7 cubic feet). The Z4 has a much larger trunk than the Cooper Convertible with its top up (9.9 vs. 7.6 cubic feet).

A low lift-over trunk design makes loading and unloading the Z4 easier. The Z4’s trunk lift-over height is 28.5 inches, while the Cooper Convertible’s liftover is 30.4 inches.

With its convertible body style, valet key and remote trunk release lockout, the Z4 offers cargo security. The Cooper Convertible’s non-lockable remote release defeats cargo security.

Servicing Ease

The engine in the Z4 is mounted longitudinally (North-South), instead of sideways, as in the Cooper Convertible. This makes it easier to service and maintain, because the accessory belts are in front.


The Z4 offers a remote vehicle starting system, so the vehicle can be started from inside the driver's house. This allows the driver to comfortably warm up the engine before going out to the vehicle. The climate system will also automatically heat or cool the interior. The Cooper Convertible doesn’t offer a remote starting system.

When two different drivers share the Z4, the memory system makes it convenient for both. Each setting activates different, customized memories for the driver and front passenger’s seat positions, outside mirror angle, climate settings and radio stations. The Cooper Convertible doesn’t offer a memory system.

In case of a sudden change of weather, the Z4 offers an optional remote convertible top that can be raised from a distance to protect the interior of the vehicle from damage. The Cooper Convertible’s top can only be opened by remote, so the driver will have to run to the car, get in, turn the ignition on and raise the top to prevent the interior from being damaged.

The Cooper Convertible’s optional cornering lamps activate a lamp on the front corner when the turn signal is activated. The Z4’s optional 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.

On extremely cold winter days, the Z4’s optional heated steering wheel provides comfort, allowing the driver to steer safely and comfortably before the car heater warms up. The Cooper Convertible doesn’t offer a heated steering wheel.

The Z4 has a standard dual zone air conditioning allows the driver and front passenger to choose two completely different temperatures so people with different temperature preferences won’t have to compromise. This makes both the driver and front passenger as comfortable as possible. Dual zone air conditioning costs extra on the Cooper Convertible.

© 1991-2018 Advanta-STAR Automotive Research. All rights reserved.

How much is your car worth?

Get the best value for your car from an Asbury dealership.

Featured Videos