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BMW i8 Convertible Roadster: Specs, Price, and Performance

Sep 2, 2020

The model year 2019 BMW i8 Convertible Roadster released in the US market during May of 2018 was first premiered during the Los Angeles Auto Show in 2017. The BMW i8 Roadster debut was accompanied by an updated version of the BMW i8 Coupe.

The two BMW i8 variants boast many similarities. From the aerodynamic design to the unique LifeDrive module architecture, the i8 Roadster takes on the Coupe’s environmentally conscious mobility, athletic built, and the uncompromised performance of a BMW. The i8’s plug-in hybrid drive system fitted in both the Roadster and the Coupe won the International Engine of the Year Award three years in a row from 2015 to 2017.

BMW i8 Convertible Roadster Photo Gallery

BMW i8 Convertible Roadster Price

The 2019 BMW i8 Roadster cost in the US market is $163,300 MSRP. The convertible i8 model is available in the US market starting from the spring of 2018. The cost excludes taxes, destination and handling charges. The BMW i8 hybrid models may be eligible for federal and state incentives where qualifies.

BMW i8 Convertible Roadster Specs: Drive System

Type: AC Synchronous Electrice Motor with Integrated Power Electronics, Charger, and Generator Mode for Recuperation

i8 Convertible Roaster Drive SystemMeasurementsData
eDrive Motor Horsepowerhp @ rpm141 @ 4,300
eDrive Motor Torquelb-ft @ rpm184 @ 0-4,100
TypeTwinPower Turbo 3-cylinder1.5 Liter
Engine Horsepowerhp @ rpm228 @ 5,800-6,000
Engine Torquelb-ft @ rpm236 @3,700
Combined Horsepower / Torquehp / lb-ft369 / 420
Battery Typeah11.6 kWh Lithium-ion / 33
BMW i8 Convertible Roadster Specs: Transmission

Type: 2-Speed Automatic Transmission for Electric Motor

Automatic Gear RatiosI / II11.30 / 5.85

Type: 6-Speed Automatic Transmission

Automatic Gear RatiosI / II / III4.46 / 2.51 / 1.56
Automatic Gear RatiosIV / V / VI / R1.14 / 0.85 / 0.67 / 3.19
Automatic Gear RatiosFinal Drive Ratio3.68
Coefficient Drag0.28

BMW i8 Convertible Roadster Specs: Performance

Acceleration 0-60 MPH AutomaticSeconds4.4
Top Speedmph155

BMW i8 Convertible Roadster Specs: Consumption

MPGE Combined69
Fuel Tank CapacityGallons11.1
Charging Time - Level 2 - 0 - 100%Hours3
Charging Time - DC 50 KW 0 - 80%Hours2.4

BMW i8 Convertible Roadster Specs: Wheels and Tires

Wheels and TiresMeasurementsData
Tire TypeMixed Tires
Front Wheel Dimensionsin20 x 7.5
Rear Wheel Dimensionsin20 x 8.5
Front Tire Dimensionsmm215/45
Rear Tire Dimensionsmm245/40

BMW i8 Convertible Roadster Specs: Exterior Dimensions

Exterior DimensionsMeasurementsData
Doors / Seats2 / 2
Length / Width / Heightin184.9 / 76.5 / 50.7
Ground Clearancein4.5
Curb Weight - Automatic Transmissionlbs3671
Front Weight Distribution - Automatic Transmission%48.5
RearWeight Distribution - Automatic Transmission%51.5

BMW i8 Convertible Roadster Specs: Interior Dimensions

Interior DimensionsMeasurementsData
Front Legroomin43.1
Front Shoulder Roomin56.7
Cargo Capacitycu ft2.3

BMW i8 Convertible Roadster Engine, Horsepower, and Top Speed

BMW i8 Convertible Roadster’s engine is a combination of a combustion engine controlling the rear wheels, and an electric motor driving the front wheels. The roadster is equipped with a six-speed automatic transmission, steering wheel-mounted paddle shifters, and the 11.6 kWh high-voltage lithium-ion battery pack featuring advanced active thermal management system.

The BMW i8 Roadster has a combined horsepower of 369 HP rated at 420 lb-ft of torque. The convertible i8 has a top speed of 155 MPH, and it accelerates from 0 to 60 MPH in 4.4 seconds.

The hybrid synchronous electric motor with BMW eDrive technology produces 141 HP with an output of 184 lb-ft of torque at 0 – 4100 RPM. The electric motor is fitted with a two-speed automatic transmission.

On the other hand, the high-precision direct injection three-cylinder combustion engine with BMW TwinPower Turbo technology is rated at 228 HP with an output of 236 lb-ft of torque at 3700 RPM.

BMW i8 Convertible Roadster MPG, Range, Charging, and Fueling

The BMW i8 Convertible Roadster achieves a combined 69 MPGe running in hybrid mode. The i8 Roadster’s stainless-steel fuel tank has a capacity of 11.1 gallons while the estimated charging time from 0 to 100% is 3 hours. Currently, the US Roadster model has not released a confirmed driving range. However, the European model is rated at an estimated range of 53 kilometers, which is equivalent to 33 miles.

BMW i8 Convertible Roadster Performance, Braking, and Handling

The BMW i8 Roadster inherited the low weight and low center of gravity design advantages of BMW engineering. The unique, aerodynamic BMW i8 concept LifeDrive module combines the lightweight aluminum Drive module with the carbon-fiber-reinforced plastic (CFRP) Life module. The special Drive module consists of the structural design, the Powertrain, suspension, high-voltage battery, and the crash system, while the Life module creates the passenger cell made from carbon-fiber-reinforced plastic (CFRP).

Designed as a hybrid, the BMW i8 Convertible Roadster comes packed with performance-oriented braking and handling functions. The all-wheel-drive i8 Roadster is paired with Hybrid-specific Dynamic Stability Control (DSC), Brake Fade Compensation, Start-off Assistant, Electromechanical Parking Brake, Brake Drying, and Brake Stand-by features as well as Dynamic Traction Control (DTC) and Dynamic Damper Control (linked with Dynamic Driving Control). The BMW i8 Roadster is designed with a 5-link rear suspension with high-performance, 4-wheel cross-drilled, ventilated 13-inch disc brakes with Anti-lock Braking System (ABS), Dynamic Brake Control (DBC) and Cornering Brake Control (CBC).

BMW i8 Convertible Roadster Exterior Design Highlights

The eye-catching scissor doors, blanked out BMW twin-kidney grilles, contoured body, and the “U-Shape” LED taillights are BMW i model-specific designs present in the BMW i8 Convertible Roadster. The i8 Roadster’s doors and hood are made from lightweight aluminum while the front bumper, fender, and rear bumpers feature the special thermoplastic. Shadowline exterior trim can be seen on the BMW i8 exclusive metallic paint. The special-fitted BMW i Radial Spoke Bicolor light alloy wheels are paired with performance tires.

BMW i8 Roadster Soft-Top Convertible Roof

The BMW i8 Roadster is designed with the all-weather, soundproof soft-top convertible rooftop which folds neatly into the rear trunk in a space-saving vertical z-shape. The all-electric convertible rooftop can open or close in just under 15 seconds while driving up to 31 miles per hour. When the car is in convertible mode, all windows automatically raise up by approximately 1.2 inches to act as traditional draught stop or windbreaker which reduces air turbulence during the drive.

BMW i8 Convertible Roadster Interior Design Highlights

The BMW i8 Roadster’s interior design is focused on a sporty theme. The BMW three-spoke multi-functional sports steering wheel features leather-wrapped design and paddle shifters. Different from the BMW i8 Coupe’s 2+2-seater Coupe design, the i8 Convertible Roadster is a genuine two-seater with more storage space. With no back seats, the i8 Roadster can accommodate approximately 2.3 cubic square feet of cargo space. The new BMW i8 Roadster’s 6-way power front seats come with three-stage heating. The 2019 BMW i8 Convertible model features carbon fiber interior trim and ivory white seats with black contrast or black leather.

BMW i8 Convertible Roadster Interior Technologies

The BMW i8 Roadster comes fully decked with standard BMW comfort and convenience interior technologies. For example, the BMW iDrive system with on-board computer, touchpad Controller, and eight programmable memory buttons is connected to the latest 8.8″ high-resolution, touch screen BMW Navigation Professional featuring 3D map, voice command, and Advanced Real Time Traffic Information. The full-color Head-up Display (HUD) with shift lights is also available in the i8 Roadster along with BMW Active Driving Assistant, Park Distance Control, Ambient Lighting, and the cool BMW i8 logo projection on doors.

BMW i8 Convertible Roadster Driving Dynamics Control

Similar to the BMW i8 Coupe, the driver can quickly change from performance-oriented drive to fuel-saving cruising with Driving Dynamics Control functions. The BMW i8 Convertible Roadster’s eDrive button and Driving Experience Control allow the driver to switch between five different driving modes.

Hybrid Drive in COMFORT Mode

The COMFORT mode in Hybrid Drive is the most balanced mixture of energy output from both the combustion engine and the electric motor.  The current speed is displayed in the instrument panel instead of the rev counter. In this mode, the electric motor controls the overtake and the acceleration from idle, while the combustion engine automatically kicks in at higher speeds.

The seamless cooperation between the combustion and electric engines creates the perfect harmony between energy efficiency and driving luxury. So, if you are going for a long drive, COMFORT mode is a good choice.

Hybrid Drive SPORT Mode

The SPORT Mode is where the aptitude of the BMW i8 unleashes. It is when the unprecedented driving pleasure of a sports coupe unveils. Combustion and electric engines are synchronized to their full potential to ensure maximum torque, speed, and stability.

In SPORT mode, extra power boosts can be supplied by the electric engine to assist the combustion engine. It maximizes acceleration and power performance while allowing the battery to recharge during deceleration, overrun and braking. The energy flow chart on the Control Display shows the BMW i8 Convertible Roadster’s energy management via the drive.

Hybrid Drive ECO PRO Mode

The ECO PRO mode is the most energy efficient hybrid drive mode. ECO PRO includes an additional efficiency display. This hybrid mode efficiently adjusts the consumption of electronics equipment in the i8 such as the heating, cooling, and fuel expenditure. This mode maximizes the driving range and fuel saving.

All-electric COMFORT Mode with eDrive

The eDrive in COMFORT Mode is purely electric drive. Drivers can enjoy the perks of getting around in a soundless and pollution free hybrid without sacrificing the aesthetics and characters of a Sports Coupe. When eDrive is activated, the combustion engine does not automatically take over until electricity is nearly exhausted.

All-electric ECO PRO Mode with eDrive

The BMW i8 Convertible Roadster’s Control Display under ECO PRO Mode in eDrive shows a full, digital instrument display in blue “power meter” providing information on the current speed, driving status. The ECO PRO in drive Mode enables the most energy savings with the most range output supplied by electric power alone. The electric motor of the BMW i8 Roadster can provide up to a speed of approximately 75 miles per hour. The combustion engine will only assist during the sudden intense throttle engagement or in an extremely low-battery situation.

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