DecodedCarsBMW Z4 vs Porsche 718
2025 BMW Z4 vs 2025 Porsche 718 — two two seaterss compared on efficiency, size, safety and reliability.
The short version
The BMW Z4 is more fuel-efficient: 28 vs 24 MPG combined in its best version.
That works out to about $450 a year less in fuel for the BMW Z4 (EPA estimate, 15,000 miles).
Across all model years since 2005, the Porsche 718 has had fewer recall campaigns (6 vs 23).
The two cars
The 2025 BMW Z4 is a two seaters offered with 2 engines (2.0L 4-cyl turbo and 3.0L 6-cyl turbo) and rear-wheel drive. It measures about 171 inches long and 73 inches wide on a 97-inch wheelbase, with a curb weight of roughly 3,464 lb (M40i 2dr Convertible).
The 2025 Porsche 718 is a two seaters offered with 3 engines (2.0L 4-cyl turbo, 2.5L 4-cyl turbo and 4.0L 6-cyl) and rear-wheel drive. It measures about 172 inches long and 71 inches wide on a 98-inch wheelbase, with a curb weight of roughly 2,943 lb (Boxster Base/S 2dr Convertible).
Buying used? The 2024 Z4 and the 2020 718 have the fewest problems in our data; avoid the 2019 Z4 and the 2024 718.
Basics
Efficiency
Performance & space
Safety & reliability
Interest
Green = clearly better. Prices are not included. How we calculate this →
Which one should you choose?
Choose the BMW Z4 if…
- You want lower fuel bills (28 vs 24 MPG)
Choose the Porsche 718 if…
- You put reliability history first (6 vs 23 recalls since 2005)
Pros & cons of each
2025 BMW Z4
- Excellent fuel economyUp to 28 MPG combined — 46% better than the average 2025 two seaters (19.2 MPG).
- No recalls so far
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
- Modest powerUp to 255 hp, versus about 473 hp for similar 2025 models.
2025 Porsche 718
- Excellent fuel economyUp to 24 MPG combined — 25% better than the average 2025 two seaters (19.2 MPG).
- No recalls so far
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
Full 2025 BMW Z4 specs →Full 2025 Porsche 718 specs →Compare fuel costs for your driving →Compare size & garage fit →