Do MX-5 Miatas Have Rotary Engines? The Surprising Truth

With its lightweight chassis, near-perfect balance, and top-down thrills, the Mazda MX-5 Miata has captured the hearts of driving enthusiasts for over 30 years. This plucky little roadster represents the essence of the sports car – a pure, driver-focused machine.

But one question has long dogged the beloved Miata – does it have a unique rotary engine under the hood?

The short answer is no, MX-5 Miatas do not have rotary engines. Since the first generation ND Miata launched in 1989, all variants have come equipped with traditional inline 4-cylinder piston engines.

In this in-depth post, we’ll uncover why Mazda decided against using their signature rotary engine in the Miata. We’ll explore the history of the Miata’s engines over the generations. And discuss why the inline-4 is the perfect match for the Miata’s driving dynamics and personality.

By the end, you’ll understand the method behind Mazda’s engine madness when it came to powering the world’s favorite roadster.

A Brief History of the Miata’s Engines

While never outfitted with a rotary engine, the Miata has seen its share of inline-4 powerplants over its storied history spanning 30+ years across four generations. Let’s take a quick tour through the engines that have powered the pint-sized Mazda over the years:

1st Generation MX-5 Miata (NA) – 1989 to 1997

The original NA Miata launched in 1989 with a 1.6L dual overhead cam (DOHC) inline-4 cylinder engine code-named B6ZE(RS). This all-aluminum engine produced 116 hp at 6,500 rpm – modest but peppy in the lightweight Miata chassis.

For the 1994 model year, Mazda introduced a larger 1.8L DOHC inline-4 making 128 hp in the new BP-ZE(RS) variant. This additional power better matched the Miata’s sports car personality.

2nd Generation MX-5 Miata (NB) – 1998 to 2005

The second-gen NB Miata continued with the 1.8L DOHC inline-4 first introduced in 1994 NA models. Power output remained unchanged at 128 hp.

For the 1999 model year, Mazda bumped up displacement to 2.0 liters in the all-new FS-DE engine. This more powerful 2.0L made 142 hp and proved a worthy upgrade for the new curvaceous NB body style.

3rd Generation MX-5 Miata (NC) – 2006 to 2015

The third-gen NC Miata launched for 2006 with an overhauled version of the 2.0L inline-4 now producing 170 eager horses thanks to variable valve timing. This new engine, coded MZR L8-DE, provided an noticeable boost in power over the 2nd generation.

Mazda continued tweaking the 2.0L, squeezing out 167 hp in later NC Miata models. While not radical, the engine refinements kept the Miata competitive against rivals like the Toyota 86.

4th Generation MX-5 Miata (ND) – 2016 to Present

The current fourth-generation ND Miata continues the tradition with an advanced 2.0L SkyActiv-G inline-4. This engine pushes 181 hp in up-level trims – the most powerful Miata engine ever from the factory.

As you can see, while the Miata’s engine displacement and power numbers have progressed over the generations, it always remained faithful to the inline-4 configuration.

Now that we’ve traced the Miata’s engine history, let’s address the rotary question once and for all…

What Exactly is a Rotary Engine?

Before we discuss why Mazda decided against using their signature rotary engine in the Miata, let’s quickly cover what exactly a rotary engine is and its unique attributes.

A rotary engine, also known as a Wankel engine after its inventor Felix Wankel, is a unique type of internal combustion engine that uses a revolving triangular rotor instead of reciprocating pistons.

Here is a quick rundown of how rotary engines work:

• The rotor spins on an eccentric shaft inside an oblong chamber known as the housing.
• As the rotor spins, its apex points create chambers that continuously expand and contract.
• Like a piston engine, these chambers intake, compress, combust, and exhaust to produce rotational power.
• The rotor keeps spinning continuously through these cycles unlike pistons that stop and change direction.

Some standout benefits and drawbacks of rotary engines include:

Pros:

• Compact size and lightweight construction compared to displacement
• Smooth operation without vibrations inherent in piston engines
• High-revving abilities and tunability for big power gains
• Generally oil-burning engines so no spark plug changes needed

Cons:

• Poor fuel efficiency as compressor side seals wear
• Carbon buildup issues as rotor seals wear out
• Apex seal failures require expensive rotor rebuilds
• Burns oil by design requiring more frequent top-offs
• Not as durable or reliable as piston engines generally

Now that you understand the fundamentals behind these unique Wankel rotary powerplants, let’s unpack why Mazda decided not to use them in their legendary MX-5 Miata roadster.

Why Doesn’t the Miata Have a Rotary Engine?

Given Mazda’s close association with rotary engines, including being the only automaker to mass-produce them for decades, you’d think the Miata would be a prime candidate for a rotary. Especially considering the rotary’s compacts dimensions and ability to spin to 9,000 rpm seemingly perfect for a lightweight sports car like the Miata.

However, Mazda determined the Miata’s character and driving dynamics were best matched to traditional piston engines. There were several factors behind this decision:

Fuel Efficiency

One of the Miata MX-5’s core design principles was exceptional fuel efficiency – especially for a nimble, open-top sports car. This was to keep the car affordable to own and operate for regular driving. Rotary engines are inherently less fuel efficient than piston engines.

The Miata’s best fuel economy is achieved around 28-30 mpg city and 35+ mpg highway with its inline-4 engine and manual transmission. Even when driven hard, real world MPG rarely dips below 25 combined.

In contrast, rotary engines struggle to crack 20 mpg in most applications. The last Mazda RX-8 with a rotary got just 16 mpg city and 22 mpg highway. Not ideal for everyday transportation.

Manufacturing Costs

Another goal with the Miata was keeping pricing accessible to attract a wide audience of driving enthusiasts. Inline-4 cylinder engines are relatively simple and cost effective to manufacture at scale.

Rotary engines require complex machining, tight tolerances, and expensive materials like titanium apex seals to produce reliable powerplants. This would have driven up costs on the budget-minded Miata significantly.

Mazda itself stated manufacturing costs for rotary engines are 2-3 times higher per unit than traditional reciprocating types. Those costs would have to be passed to consumers in the form of large price increases on lower volume Miata models.

Reliability Concerns

Reliability is crucial for any daily driven vehicle. Unfortunately, rotaries have battled durability issues and service headaches since their introduction. Carbon buildup, flooding, premature apex seal wear, and eccentric shaft wobble plagued first generations engines.

Even modern rotary engines require meticulous care and maintenance to achieve reasonable lifespan. Short oil change intervals, Seal Conditioner additives, and Banjo bolt filters help but can’t prevent inherent issues.

Compare this to the stout reliability of the Miata’s inline-4 engines that can easily run over 100,000 miles with basic maintenance. Plus piston engines have vast aftermarket support for rebuilding that can’t match rare rotary components.

In summary, Mazda decided the finicky nature and specialized care of rotary engines conflicted with the Miata’s mission as an affordable, everyday sports car. The Miata deserved a fuss-free, durable engine to match its accessible character.

Why the Inline-4 Was the Miata’s Perfect Engine?

Rather than force feeding the Miata an ill-fitting rotary, Mazda designed the ideal inline-4 cylinder engine tailored specifically to the car’s driving dynamics and personality.

While lacking the sex appeal of a high-strung rotary howling to 9,000 rpm, the Miata’s inline-4 delivers where it matters most:

1. Linear Power Delivery

The Miata prioritizes momentum and handling over raw power. Unlike the peaky powerbands of high-revving rotaries, inline-4 engines make torque and horsepower in a linear, predictable fashion.

This allows better control and quicker launches from lower RPMs – important for navigating tight turns and technical sections. Peak torque arrives at just 4,600 rpm in the latest 2.0L SkyActiv engine.

2. Compact, Mid-Engine Layout

The inline-4’s small, narrow dimensions permit an optimal front mid-engine, rear-wheel drive layout in the Miata chassis. This places the engine’s mass centered behind the front axle for ideal 52/48 weight distribution and balanced handling.

Accommodating the rotor housing of a rotary would have required suboptimal front-engine placement shifting weight forward. Also challenging in the Miata’s cramped engine bay.

3. Lower Reciprocating Mass

With fewer moving parts than large V6s or V8s, inline-4 engines have less reciprocating mass shaking the chassis. This pays dividends in balance and precision for a sports car like the Miata.

The rhythmic impulse vibrations of a rotary would have diminished the Miata’s smooth handling and subtle communication.

4. Tunability Potential

While rotaries can make big power with basic mods, the Miata’s inline-4 proved more tunable for serious enthusiasts. An entire industry of turbocharging, supercharging, and engine swaps exists to push inline-4 Miata’s well past 200 hp to the wheels.

Doing this reliably and cost effectively would be near impossible with the limited aftermarket for rotary engines.

5. Economy and Reliability

Lastly, the inline-4 engine’s proven durability, affordable maintenance, and excellent fuel efficiency cemented it as the best match for the Miata’s everyday drivability. A finicky rotary would have sabotaged the car’s broad appeal.

Would a Rotary Work in the Miata?

Hypothetically, could Mazda have engineered a rotary to work in the Miata package had they dedicated the resources? More likely earlier in the Miata’s history before emissions and fuel economy became priorities.

However, the business case to invest millions reinventing an engine unsuitable for the Miata’s character just doesn’t make sense for a low volume product. Mazda made the right call sticking with their proven inline-4 engines.

Perhaps if Mazda brings back the rotary engine in their rumored upcoming RX-9 sports car, we could see an experimental Miata outfitted with one by the factory or an ambitious tuner.

Until then, the iconic high-revving rotary remains separate from the Miata lineage – despite the wishes of some enthusiasts.

The Miata’s Winning Formula Endures

In the end, Mazda struck gold with the MX-5 Miata formula – minimal weight, impeccable balance, and an eager inline-4 powerplant perfectly in tune with the chassis.

This package spawned the world’s most successful two-seat convertible sports car, selling over 1 million units across four decades.

While a rotary engine under the hood may have burnished the Miata’s uniqueness and pedigree, it would have upended the car’s winning balance.

Here’s to another 30 years of the Mazda MX-5 Miata’s formula staying true to its roots with an inline-4 cylinder engine up front motivating driving purists and autocrossers alike!

Conclusion

The MX-5 Miata has never needed gimmicky powertrain choices to cement its legacy. As the world’s best selling roadster exceeding 1 million sales, the Miata’s formula of a lightweight chassis, near perfect balance, and just enough power clearly resonates across generations.

Under the hood, smooth, tunable inline 4-cylinder engines reward skilled drivers while remaining accessible and economical for daily use. Never flashy, always effective.

While a high-revving rotary engine spins an intriguing story, realities of efficiency, reliability, and manufacturing costs preclude it from powering the people’s roadster. The Miata will likely stay true to its roots – an honest enthusiast’s car focused on the journey, not showy engines.

Here’s to another 30 years of momentum carrying happy MX-5 drivers through the turns, top down, inline-4 wailing. No smoke and mirrors needed.