VS
At a Glance
Power
335hp @ 5000
382hp @ 5800
Torque
368lb-ft @ 1600
369lb-ft @ 1800
Fuel
25 mpg est.
26 mpg est.
Engine
3.0 L/183ci
3.0 L/183ci
Choosing between the BMW 8 Series and the BMW Z4 is one of the most common decisions car buyers in the United States face. The BMW 8 Series delivers 335hp @ 5000 while the BMW Z4 produces 382hp @ 5800. On fuel, the 8 Series returns 25 mpg est. while the Z4 uses 26 mpg est. — important in a market where fuel prices change monthly. Pricing starts at $94,500 for the 8 Series and $68,400 for the Z4. Both vehicles have their merits. The right choice depends on your priorities: fuel economy, performance, towing ability, safety features or total cost of ownership. This comparison covers every specification available so you can make an informed decision.
Specification
BMW 8 Series840i Convertible 2026 - From $94,500
BMW Z4M40i Roadster 2026 - From $68,400
Performance
Power Output (hp)
335hp @ 5000
382hp @ 5800
Torque (lb-ft)
368lb-ft @ 1600
369lb-ft @ 1800
Engine & Drivetrain
Engine Capacity
3.0 L/183ci
3.0 L/183ci
Engine Layout
Inline
Inline
Cylinders
6
6
Fuel Type
Gasoline
Gasoline
Forced Induction Device
Turbocharged
Turbocharged
Transmission
Automatic
Automatic
Number of Gears
8
6
Drive Wheels
Rear Wheel Drive
Rear Wheel Drive
Fuel Economy
Fuel Economy (Combined, est.)
25 mpg est.
26 mpg est.
Fuel Economy - City (mpg)
21mpg
23mpg
Fuel Economy - Highway (mpg)
29mpg
29mpg
Fuel Tank Capacity (gal)
18gal
13.7gal
Dimensions
Length (in)
191.1in
170.7in
Width (in)
74.9in
73.4in
Height (in)
52.7in
51.4in
Wheelbase (in)
111.1in
97.2in
Curb Weight (lbs)
4211lbs
3543lbs
Safety
ABS
✓ Standard
✓ Standard
Brake Assist
✓ Standard
✓ Standard
Stability Control
✓ Standard
✓ Standard
Traction Control
✓ Standard
✓ Standard
Driver Airbag
✓ Standard
✓ Standard
Passenger Airbag
✓ Standard
✓ Standard
Side Airbags Front
✓ Standard
✓ Standard
Features & Tech
Air Conditioning
✓ Standard
✓ Standard
Climate Control
✓ Standard
✓ Standard
Cruise Control
✓ Standard
✓ Standard
Adaptive Cruise Control
✓ Standard
✓ Standard
Bluetooth
✓ Standard
✓ Standard
Backup Camera
✓ Standard
✓ Standard
Rear Parking Aid
✓ Standard
✓ Standard
Heated Seats
✓ Standard
✓ Standard
Power Seat Adjustment
✓ Standard
✓ Standard
Keyless Entry
✓ Standard
✓ Standard
Alloy Wheels
✓ Standard
✓ Standard
The Verdict
Which Wins?
Overall Winner
BMW Z4
3 / 4 categories
Performance
Z4
Fuel Economy
Z4
Value
Z4
Practicality
Tied
Pros & Cons
BMW 8 Series
Well-rounded specification
Higher fuel consumption (25 mpg est.)
Higher starting price
BMW Z4
Better fuel economy (26 mpg est.)
Lower starting price ($68,400)
Few notable weaknesses
Frequently Asked Questions
Which is more fuel efficient, the 8 Series or Z4?
The 8 Series gets 25 mpg est. and the Z4 gets 26 mpg est. on the combined cycle. The Z4 is the more fuel-efficient choice. In real-world conditions with a mix of highway and urban driving, actual figures will be slightly higher.
Which has more power, the 8 Series or Z4?
The 8 Series produces 335hp @ 5000 and 368lb-ft @ 1600 of torque while the Z4 delivers 382hp @ 5800 and 369lb-ft @ 1800 of torque. The Z4 is the more powerful option.
What is the price difference between the 8 Series and Z4?
The 8 Series starts from $94,500 and the Z4 from $68,400. The Z4 is cheaper by $26,100 at this variant level. Final on-the-road pricing varies by dealer and specification.
Should I buy the 8 Series or the Z4?
It depends on your priorities. If fuel economy matters most, check the mpg figures above. If you need towing capacity, compare the towing ratings. For day-to-day driving - commutes, school runs and highway trips - consider ground clearance, service network coverage, and total cost of ownership including insurance and maintenance. Use the spec tables above to compare every detail before making your decision.