Everyone in the car enthusiast world knows the saying: “Miata is always the answer.” And for good reason. The Mazda Miata, particularly the Nb Miata generation, has cemented its place as an iconic roadster, praised for its handling, affordability, and pure driving joy. But in a market where NB Miata prices are steadily climbing and finding well-maintained examples becomes increasingly challenging, is it still always the answer? Perhaps it’s time to consider a compelling alternative: the BMW Z3 1.9.
While BMW is often associated with its legendary inline-six engines, the four-cylinder models, especially those powered by the M44B19 engine, often fly under the radar. In the US market, these include the E30 318is, E36 318is, 318ti, and the Z3 1.9. For those seeking a roadster experience, the Z3 1.9 presents a unique and often overlooked option. While the allure of more powerful Z3 variants (and their Z4 successors) with six-cylinder engines is undeniable, the 1.9-liter M44B19 Z3 offers a different kind of appeal, especially for drivers who prioritize balance, fuel efficiency, and a rewarding driving experience without excessive power. Furthermore, the robust nature of the four-cylinder Z3 can be advantageous, as the inline-six models are known to sometimes suffer from differential mount issues, particularly the 2.5, 2.8, and 3.0 variants.
Z3 1.9 vs. the NB Miata: A Fair Comparison
It’s true that the BMW Z3 1.9 often gets labeled as “underpowered” in reviews. However, when you delve into the numbers, the power-to-weight ratio is remarkably similar to the beloved 1.6-liter NA Miata. Interestingly, while few complain about the NA Miata being underpowered, instead celebrating its nimble handling, the Z3 1.9 frequently faces this criticism. Having owned and tracked multiple Miatas across different generations (NA, NB, NC), and now experiencing the Z3 1.9, it’s clear that the Z3 deserves to be in the same conversation as the Miata when it comes to driving enjoyment. In fact, in some aspects, the Z3 arguably surpasses the Miata. The Z3’s interior feels more refined, and the overall car has a more substantial and solid feel, which is understandable given its slightly heavier weight.
Let’s break down the specifications to see how these roadsters compare:
| Model | Weight (lbs) | Horsepower (hp) | Torque (tq) |
|---|---|---|---|
| NA Miata (1.6L) | 2092 | 115 | 110 |
| NB Miata (1.8L) | 2348 | 140 | 119 |
| NC Miata (2.0L) | 2535 | 158 | 139 |
| Z3 1.9 | 2600 | 138 | 133 |
On track, the Z3 1.9 proves its mettle. During an initial track day, a lap time of 1:34.0 at Thunderhill West was achieved on budget-friendly Federal Evoluzion ST1 tires. This lap time firmly places the Z3 1.9 in the territory of the NA Miata. While the performance of an NB Miata is undeniably attractive, the Z3 1.9 offers comparable power and a slightly heavier chassis. For those seeking a boost in performance from the Z3 1.9 without major modifications, ECU tuning presents an appealing option. While engine swaps to achieve 200hp M42B19 engines exist, street legality, especially in regions like California, often limits such drastic measures. Bolt-on modifications and ECU tuning offer more accessible and compliant avenues for enhancing the Z3 1.9’s performance.
BMW Z3 1.9 roadster demonstrating its handling capabilities on a race track during a track day event.
Unleashing Hidden Potential: The ECU Flash for the Z3 1.9
For enthusiasts looking to extract more from the M44B19 engine in their Z3 1.9, ECU tuning is a game-changer. Companies like Midnight Tuning Solutions, a Canadian specialist in BMW engine tuning, offer flash tunes specifically for the M44B19. Unlike older chip swaps, these modern tunes require sending your DME (Digital Motor Electronics) to them for flashing. However, the results are well worth the effort. For around $300, these tunes promise gains of approximately +18 horsepower and +12 lb-ft of torque, along with raising the rev limit to 7000 RPM. Imagine transforming the Z3 1.9 into a roadster boasting 156 horsepower, 145 lb-ft of torque, and a thrilling 7000 RPM redline.
This isn’t just wishful thinking; the transformation is real. While dyno figures haven’t been personally verified, the subjective improvement is undeniable. The Z3 1.9 feels like a completely different car, particularly in the mid-range and upper rev ranges, from around 4000 RPM upwards. The increased rev limit is also noticeable, potentially even exceeding 7000 RPM without the rev limiter engaging – something to be mindful of. Overall, the ECU flash provides a significant and satisfying performance increase. A 13% power boost is genuinely noticeable in a car that starts with modest figures, and the $300 investment is remarkably affordable for a modification that is both stealthy and emissions-compliant.
Close-up view of the BMW Z3 1.9 engine bay, showcasing the M44B19 four-cylinder engine, a key component for performance tuning.
Power-to-Weight Ratio: Z3 1.9 Tuned vs. NB Miata
To quantify the impact of the ECU tune, let’s revisit the power-to-weight ratio comparison, incorporating the performance enhancements:
| Model | Weight (lbs) | Wheel Horsepower (whp) | lbs/whp | Torque (tq) |
|---|---|---|---|---|
| Z3 1.9 (Tuned) | 2820* | 129.5** | 21.78 | 145 |
| NB Miata (Stock) | 2530* | 116.2** | 21.77 | 119 |
*Weight includes car, driver, and gear.
**Wheel horsepower estimated at 83% of crank horsepower.
As the numbers reveal, a lightly modified Z3 1.9 with an ECU flash achieves a power-to-weight ratio virtually identical to a stock NB Miata. Furthermore, the Z3 1.9 boasts a torque advantage of over 10% compared to the NB Miata (145 lb-ft vs. 119 lb-ft, a +22% difference). This translates to improved responsiveness and mid-range pull on both the street and the track.
Conclusion: The Z3 1.9 – A Smart Roadster Choice in a Miata World
The NB Miata remains an exceptional roadster and a benchmark in its class. “Miata is always the answer” is a testament to its enduring appeal. However, as NB Miatas become scarcer and prices continue to rise, the BMW Z3 1.9 emerges as a compelling and often more affordable alternative. For drivers who appreciate the charm of a slow roadster and prioritize a balanced and engaging driving experience, the Z3 1.9, especially when enhanced with an ECU flash, deserves serious consideration. It offers a refined interior, solid build quality, and, with a few smart modifications, performance that rivals the beloved NB Miata. So, while the NB Miata may be a fantastic answer, perhaps it’s time to ask a slightly different question and discover the merits of the BMW Z3 1.9. You might just find that the Z3 1.9 is the answer you were looking for all along.
