Car comparison

BMW 8 Series (G15) 840ivsBMW X4 (G02) M40i

Compare specs, acceleration, fuel consumption, dimensions, practicality, and estimated running costs side by side.

New comparison

BMW 8 Series (G15)

840i

340 hp2998 ccGasolineAWDAutomaticTurbochargedCoupe2019-2020
VS

BMW X4 (G02)

M40i

354 hp2998 ccGasolineAWDAutomaticTurbocharged2018-2019

Comparison overview

Use the estimates as comparison hints and verify exact figures before making decisions.

Best choices

BMW 8 Series (G15) 840i

  • Quickest 0-100 km/h
    4.7 s
  • Fastest top speed
    265 km/h
    165 mph Unrestricted
    250 km/h
    155 mph Restricted
  • Highest torque
    500 Nm
    369 lb-ft
  • Lightest
    1,770 kg
    3,902 lb
  • Lowest combined fuel consumption
    7.7 L/100 km
    30.5 mpg US
    36.7 mpg UK
  • Lowest city consumption
    9.6 L/100 km
    24.5 mpg US
    29.4 mpg UK
  • Lowest highway consumption
    6.5 L/100 km
    36.2 mpg US
    43.5 mpg UK
  • Best estimated range
    883 km
    549 mi
  • Best performance score
    72/100
  • Best economy score
    86/100

BMW X4 (G02) M40i

  • Most powerful
    354 hp
    264 kW
  • Best power-to-weight
    194 hp/t
    145 kW/t
    5.2 kg/hp
  • Largest trunk
    525 L
  • Best overall score
    73/100
  • Best practicality score
    76/100

Specification comparison

Specification comparison
ModelBMW8 Series (G15)840iBMWX4 (G02)M40i
Power
340hp254kW
354hp264kW
Torque
500Nm369lb-ft
500Nm369lb-ft
Curb weight
1,770kg3,902lb
1,825kg4,023lb
Gross weight
2,280kg5,027lb
2,530kg5,578lb
Top speed
Unrestricted
265 km/h165 mph
Restricted
250 km/h155 mph
Calculated
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Calculated
To 99% top speed
66.4s99% target: 262 km/h / 163 mph
Calculated
69.6s99% target: 257 km/h / 160 mph
Calculated
0-100 km/h
4.7s
4.8s
0-200 km/h
16.7s
Calculated
17.9s
Calculated
0-60 mph
4.5s
Calculated
4.6s
Calculated
Fuel consumption
7.7L/100 km30.5mpg US36.7mpg UK
9.1L/100 km25.8mpg US31.0mpg UK
Fuel consumption city
9.6L/100 km24.5mpg US29.4mpg UK
11.5L/100 km20.5mpg US24.6mpg UK
Fuel consumption highway
6.5L/100 km36.2mpg US43.5mpg UK
7.7L/100 km30.5mpg US36.7mpg UK
Quarter mile
12.8s
Calculated
13.0s
Calculated
Power-to-weight
192hp/t143kW/t87hp/1000 lb
Calculated
194hp/t145kW/t88hp/1000 lb
Calculated
Torque-to-weight
282Nm/t189lb-ft/ton
Calculated
274Nm/t183lb-ft/ton
Calculated
Estimated range
883km549mi
Calculated
714km444mi
Calculated
Displacement
2,998cc183cu in
2,998cc183cu in
Length
4,843mm191in
4,733mm186in
Width
1,902mm75in
1,938mm76in
Height
1,341mm53in
1,621mm64in
Wheelbase
2,822mm111in
2,864mm113in
Front track
1,627mm64in
1,615mm64in
Rear track
1,642mm65in
1,624mm64in
Ground clearance
121mm5in
204mm8in
Trunk volume
420L
525L
Max trunk volume-
1,430L
Doors
2
5
Seats
4
5
Fuel tank
68L
65L
CO2 emissions-
206g/km

Performance charts

Use the estimates as comparison hints and verify exact figures before making decisions.

Dyno simulation

Estimated stock-style power and torque curves by engine speed.

BMW 8 Series (G15) 840iBMW X4 (G02) M40iPowerTorque
  • BMW 8 Series (G15) 840i: Power / Torque
  • BMW X4 (G02) M40i: Power / Torque
Dyno simulation data table
VehiclePeak power RPMPeak torque RPMMax engine speed
BMW8 Series (G15)840i5,000-6,500 rpm1,600-4,500 rpm6,750 rpm
BMWX4 (G02)M40i5,500-6,500 rpm1,550-4,500 rpm6,750 rpm

Acceleration curve

Estimated speed over time for selected vehicles.

Acceleration and drag-race table
MetricBMW8 Series (G15)840iBMWX4 (G02)M40i
Acceleration checkpoints
0-60 mph
0-97 km/h
4.5 s
4.6 s
0-100 km/h
0-62 mph
4.7 s
4.8 s
0-200 km/h
0-124 mph
16.7 s
17.9 s
Top speed
Unrestricted
265 km/h165 mph
Restricted
250 km/h155 mph
Likely limited
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Likely limited
Drag race simulation
60 ft
18 m
2.1 s
2.1 s
330 ft
101 m
5.6 s
5.6 s
1/8 mile
201 m
8.4 s
8.4 s
1000 ft
305 m
10.8 s
10.9 s
1/4 mile
402 m
12.8 s
13.0 s
Trap speed
1/4 mile
402 m
179 km/h
111 mph
175 km/h
109 mph

Power comparison

Bar comparison chart for Power. Higher is better · hp / kW

Chart data table
VehicleValue
BMW8 Series (G15)840i
340 hp
254 kW
BMWX4 (G02)M40i
354 hp
264 kW

BMW X4 (G02) M40i has 14 hp more than BMW 8 Series (G15) 840i.

The biggest power difference is between BMW 8 Series (G15) 840i and BMW X4 (G02) M40i: 14 hp (10 kW).

Torque comparison

Bar comparison chart for Torque. Higher is better · Nm / lb-ft

Chart data table
VehicleValue
BMW8 Series (G15)840i
500 Nm
369 lb-ft
BMWX4 (G02)M40i
500 Nm
369 lb-ft

Curb weight comparison

Bar comparison chart for Curb weight. Lower is better · kg / lb

Chart data table
VehicleValue
BMW8 Series (G15)840i
1,770 kg
3,902 lb
BMWX4 (G02)M40i
1,825 kg
4,023 lb

Top speed without limiter comparison

Bar comparison chart for Top speed without limiter. Higher is better · km/h / mph

Chart data table
VehicleValue
BMW8 Series (G15)840i
Unrestricted
265 km/h165 mph
Restricted
250 km/h155 mph
BMWX4 (G02)M40i
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph

0-100 km/h comparison

Bar comparison chart for 0-100 km/h. Lower is better · seconds

Chart data table
VehicleValue
BMW8 Series (G15)840i4.7 s
BMWX4 (G02)M40i4.8 s

Although BMW X4 (G02) M40i has more power, BMW 8 Series (G15) 840i is quicker from 0-100 km/h.

The biggest 0-100 km/h difference is between BMW 8 Series (G15) 840i and BMW X4 (G02) M40i: 0.1 s.

Fuel consumption comparison

Bar comparison chart for Fuel consumption. Lower is better · L/100 km / mpg US / mpg UK

Chart data table
VehicleValue
BMW8 Series (G15)840i
7.7 L/100 km
30.5 mpg US
36.7 mpg UK
BMWX4 (G02)M40i
9.1 L/100 km
25.8 mpg US
31.0 mpg UK

The biggest fuel consumption difference is between BMW 8 Series (G15) 840i and BMW X4 (G02) M40i: 1.4 L/100 km.

Power-to-weight comparison

Bar comparison chart for Power-to-weight. Higher is better · hp/t / kW/t

Chart data table
VehicleValue
BMW8 Series (G15)840i
192 hp/t
143 kW/t
5.2 kg/hp
BMWX4 (G02)M40i
194 hp/t
145 kW/t
5.2 kg/hp

Estimated range comparison

Bar comparison chart for Estimated range. Higher is better · km / mi

Chart data table
VehicleValue
BMW8 Series (G15)840i
883 km
549 mi
BMWX4 (G02)M40i
714 km
444 mi

Performance spider chart

Radar chart comparing normalized performance and fuel-consumption scores.

Chart data table
VehiclePowerAccelerationTop speed
BMW8 Series (G15)840i
340 hp
254 kW
4.7 s
Unrestricted
265 km/h165 mph
Restricted
250 km/h155 mph
BMWX4 (G02)M40i
354 hp
264 kW
4.8 s
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph

Most attractive quadrant

Scatter chart with performance score on the X axis and practicality score on the Y axis.

Chart data table
VehiclePerformance scorePracticality score
BMW8 Series (G15)840i
Power
340 hp
254 kW
0-100 km/h4.7 s
Top speed
Unrestricted
265 km/h165 mph
Restricted
250 km/h155 mph
Doors/seats
2 doors
4 seats
Trunk
420 L
14.8 cu ft
Length
4,843 mm
190.7 in
Height
1,341 mm
52.8 in
BMWX4 (G02)M40i
Power
354 hp
264 kW
0-100 km/h4.8 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Doors/seats
5 doors
5 seats
Trunk
525 L
18.5 cu ft
Length
4,733 mm
186.3 in
Height
1,621 mm
63.8 in

Performance vs fuel economy

Cars closer to the top-right corner combine stronger performance with better fuel economy scores.

Performance vs fuel economy data table
VehiclePerformance scoreFuel economy score
BMW8 Series (G15)840i
Power
340 hp
254 kW
0-100 km/h4.7 s
Top speed
Unrestricted
265 km/h165 mph
Restricted
250 km/h155 mph
7.7 L/100 km
30.5 mpg US
36.7 mpg UK
BMWX4 (G02)M40i
Power
354 hp
264 kW
0-100 km/h4.8 s
Top speed
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
9.1 L/100 km
25.8 mpg US
31.0 mpg UK

BMW 8 Series (G15) 840i is closest to the top-right balance target for performance and fuel economy.

Acceleration vs fuel consumption

Cars closer to the lower-left corner offer a better mix of quick acceleration and low fuel consumption.

Acceleration vs fuel consumption data table
VehicleFuel consumption, L/100 km0-100 km/h, s
BMW8 Series (G15)840i
7.7 L/100 km
30.5 mpg US
36.7 mpg UK
4.7 s
BMWX4 (G02)M40i
9.1 L/100 km
25.8 mpg US
31.0 mpg UK
4.8 s

Power-to-weight vs fuel consumption

The shaded area favors higher power-to-weight with lower combined fuel consumption.

Power-to-weight vs fuel consumption data table
VehiclePower-to-weight, hp/tFuel consumption, L/100 km
BMW8 Series (G15)840i
192 hp/t
143 kW/t
5.2 kg/hp
7.7 L/100 km
30.5 mpg US
36.7 mpg UK
BMWX4 (G02)M40i
194 hp/t
145 kW/t
5.2 kg/hp
9.1 L/100 km
25.8 mpg US
31.0 mpg UK

Detailed score breakdown

Detailed score breakdown
VehicleBMW8 Series (G15)840iBMWX4 (G02)M40i
Power
340 hp
254 kW
354 hp
264 kW
Torque
500 Nm
369 lb-ft
500 Nm
369 lb-ft
Acceleration
4.7 s
4.8 s
Top speed
Unrestricted
265 km/h165 mph
Restricted
250 km/h155 mph
Unrestricted
260 km/h162 mph
Restricted
250 km/h155 mph
Lightness
1,770 kg
3,902 lb
1,825 kg
4,023 lb
Fuel consumption
7.7 L/100 km
30.5 mpg US
36.7 mpg UK
9.1 L/100 km
25.8 mpg US
31.0 mpg UK
Practicality
Doors/seats
2 doors
4 seats
Trunk
420 L
14.8 cu ft
Length
4,843 mm
190.7 in
Height
1,341 mm
52.8 in
Doors/seats
5 doors
5 seats
Trunk
525 L
18.5 cu ft
Length
4,733 mm
186.3 in
Height
1,621 mm
63.8 in
Range score
883 km
549 mi
714 km
444 mi
CO2 score
-
206 g/km
Trunk score
420 L
14.8 cu ft
525 L
18.5 cu ft
Power-to-weight score
192 hp/t
143 kW/t
5.2 kg/hp
194 hp/t
145 kW/t
5.2 kg/hp
Overall
Fixed score
Fixed score

Fuel cost and annual usage

Estimate running costs from combined consumption, your annual distance, and the fuel price in your local currency.

Enter the fuel price in your local currency, for example €/L, $/gal, £/L or any other local currency.

LC = Local Currency

Fuel cost and annual usage
VehicleBMW 8 Series (G15) 840iBMW X4 (G02) M40i
Consumption7.7 L/100 km30.5 mpg US36.7 mpg UK9.1 L/100 km25.8 mpg US31 mpg UK
Cost / 100 km13.48 LC100 km15.92 LC100 km
Cost / 100 mi21.69 LC100 mi25.63 LC100 mi
Annual fuel used1,155 L305 US gal254 UK gal1,365 L361 US gal300 UK gal
Annual fuel cost2,021 LC/year2,389 LC/year

Head-to-head comparisons

BMW 8 Series (G15) 840i

  • Is 55 kg lighter
  • Is 0.1 s quicker from 0-100 km/h
  • Has 5 km/h (3 mph) higher top speed
  • Uses 1.4 L/100 km less fuel
  • Has 169 km (105 mi) more estimated range

Pros

  • Quickest 0-100 km/h in this comparison
  • Highest top speed
  • Highest torque
  • Lightest
  • Lowest combined fuel consumption
  • Best estimated range

Cons

  • Lowest power
  • Smallest trunk

BMW X4 (G02) M40i

  • Has 14 hp more
  • Has 2 hp/t better power-to-weight
  • Has 105 L more trunk volume

Pros

  • Most powerful
  • Best power-to-weight ratio
  • Largest trunk

Cons

  • Slowest 0-100 km/h
  • Highest combined fuel consumption
  • Heaviest
  • Lowest top speed

Choose cars to compare

Brand
Model
Generation
Engine or modification
BMW 8 Series (G15) 840i
BMW X4 (G02) M40i
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BMW 8 Series (G15) 840i vs BMW X4 (G02) M40i - car comparison - FastVsFaster