MX-5 Miata NA: 1.6L Vs 1.8L Engine Comparison

The original MX-5 Miata made its debut in 1989, ushering in a new era of affordable, lightweight sports cars. With its precise handling, open-top fun, and zippy personality, the first-gen Miata delivered the essence of the British roadsters that inspired it.

But which engine is best suited for the Miata NA – the 116 hp 1.6L or the 133 hp 1.8L?

While the 1.8L offers more power, the lighter 1.6L optimizes the chassis balance and handling. Ultimately, it comes down to your priorities – a rev-happy momentum machine or a torque-filled powerhouse. This in-depth comparison examines the strengths and weaknesses of both MX-5 Miata NA engine options.

We’ll analyze horsepower and torque output, weight distribution impacts, tuning potential, real-world fuel economy, reliability, and overall performance personality. By the end, you’ll have all the details to choose if the sweet spot for your NA Miata is the 1.6L or 1.8L engine.

Introduction to the MX-5 Miata NA

Before diving into the engines, let’s recap why the first-gen MX-5 Miata was such a hit. Mazda perfectly captured the classic British sports car vibe of the 1960s with a reliable, affordable, and modern roadster.

The NA Miata arrived at just the right time too. Sports cars had become bloated and complex. But the Miata recaptured the lightweight ethos of classics like the Lotus Elan and Triumph Spitfire.

Two trim levels were offered – the base model with crank windows and steel wheels, and the uplevel LE with power accessories and alloy wheels. But the main difference was under the hood.

The base Miata came equipped with a 1.6L inline-4 making 116 hp and 100 lb-ft of torque. The LE bumped up to a 1.8L inline-4 producing 133 hp and 114 lb-ft.

This gave buyers a choice between an engine focused on balance and handling purity or one emphasized power. Let’s see how they compare.

Specs Comparison

Spec	1.6L	1.8L
Engine	1.6L DOHC Inline-4	1.8L DOHC Inline-4
Horsepower	116 hp @ 6,500 RPM	133 hp @ 6,500 RPM
Torque	100 lb-ft @ 5,500 RPM	114 lb-ft @ 5,500 RPM
Redline	7,200 RPM	7,000 RPM
Compression	9.4:1	9.0:1
Weight	258 lbs	324 lbs
0-60 mph	8.4 seconds	8.1 seconds

Horsepower and Torque Comparison

The most obvious distinction between the 1.6L and 1.8L Miata engines comes down to horsepower and torque output.

With 133 hp and 114 lb-ft torque, the 1.8L produces 17 more horsepower and 14 lb-ft more torque than the 116 hp, 100 lb-ft 1.6L.

The additional power doesn’t radically transform the character of the car, but it provides a bit more punch, especially when revved out. Stomp on the throttle at highway speeds and the 1.8L pulls stronger into the higher RPM range.

This graph shows the horsepower and torque curves of both engines:

The 1.8L exceeds the 1.6L in both horsepower and torque output across the powerband.

You can see the 1.8L’s advantage in peak power. It also hits its torque peak 600 RPM sooner at 5,500 RPM.

Translated to real world driving, the fatter midrange gives the feeling of the 1.8L being livelier off the line and through the gears. It’s not a night and day difference, but the additional torque adds more punchiness to everyday driving.

For some context, let’s look at 0-60 mph acceleration times for each engine:

1.6L Miata NA – 8.4 seconds

1.8L Miata NA – 8.1 seconds

So in stock form, the 1.8L trims about 1/4 second off the 0-60 mph run. The extra power also helps maintain momentum when exiting corners.

While the 1.8L isn’t radically quicker, the added torque makes the Miata feel a bit more eager to rev and pull through the powerband.

Weight Distribution Impact

Beyond raw power numbers, a key consideration is how the engine affects overall vehicle balance and handling.

Here’s a quick refresher on the first-gen Miata’s specs:

RWD layout with 50/50 weight distribution

Double wishbone front / multi-link rear suspension
Near perfect chassis balance and precision handling

So any changes to weight distribution are very noticeable from behind the wheel. And the heavier 1.8L engine does influence balance to a degree.

The bare 1.6L engine weighs about 258 lbs while the 1.8L tips the scales at 324 lbs, a difference of 66 lbs.

Mounted way out front over the front axle, those extra pounds make the 1.8L-powered Miata a bit more nose-heavy.

How does this translate driving experience? The lighter 1.6L has a sharper turn-in and feels even more poised through quick transitions and tight corners. The 1.8L doesn’t handle poorly by any means, but it loses just a hint of that patented Miata agility.

If you plan to take your NA to autocross events or really push it through twisty canyon roads, the 1.6L’s nimbler reflexes give it an advantage.

But in casual driving, the 1.8L’s extra weight is tough to notice. It doesn’t drastically upset the handling balance, just dulls it slightly. For many drivers, the perk of extra torque outweighs the small deficit in weight distribution.

Tuning Potential Comparison

The MX-5 Miata was never the most powerful sports car. But the thrilling handling has always made it a prime target for modifications and added horsepower. What’s the tuning potential of the 1.6L versus the 1.8L?

With basic bolt-on modifications like intake, exhaust, headers, etc., you can expect to add 15-25 hp to either Miata NA engine. The 1.6L can be tuned to around 130-135 hp and the 1.8L sees gains to 150-160 hp.

For serious power upgrades, forced induction is the next step. Lightly modified engines can usually handle ~7 PSI from a turbo or supercharger kit safely.

With a basic bolt-on turbo kit, expect the following output:

1.6L – Around 180 whp
1.8L – Around 210 whp

The larger displacement of the 1.8L gives it more room to breathe when pushed to higher power levels. More aggressive builds exceeding 250 whp are also more reliably achieved with the 1.8L bottom end.

So while both engines are responsive to modifications, the 1.8L ultimately offers greater tuning potential. Chassis upgrades help handle the added power, especially wider tires to maximize grip.

Fuel Economy Comparison

Sports cars are rarely associated with good gas mileage. But one of the Miata’s charms has always been delivering fun without being too punishing at the pump.

The EPA fuel economy ratings are nearly identical between the two engines:

1.6L Miata NA EPA Ratings

City: 21 mpg
Highway: 28 mpg

1.8L Miata NA EPA Ratings

City: 22 mpg
Highway: 30 mpg

So on paper, the 1.8L holds a tiny 1-2 mpg advantage in city and highway driving. However, in real world conditions, the mileage is essentially a wash between the two engines.

Factors like driving style and transmission choice make far more impact on fuel economy than the engine size. Expect low to mid 20s mpg in mixed driving for either Miata NA.

For maximum efficiency, the 5-speed manual transmissions yield slightly better mileage than the available 4-speed automatic. The manuals are also much more engaging for the true Miata driving experience.

So when it comes to fuel consumption, neither engine gives the Miata NA a significant advantage. Running costs come down to maintenance and insurance more than gas.

Reliability Comparison

When buying an older Miata NA, reliability becomes a key consideration. Problems that may have been overlooked decades ago need to be addressed to keep your classic roadster running strong.

The good news is both the 1.6L and 1.8L engines have proven robustly reliable when properly maintained. There are examples of each powerplant exceeding 200,000+ miles.

However, when evaluating a high mileage NA Miata, be diligent about checking service records. Pay attention to:

Key Maintenance Items:

Regular oil changes

New timing belt, water pump, seals at 60k mile intervals
Transmission fluid changes
Replacing worn belts, hoses, gaskets

Tuning up ignition components

Problem Areas:

Tired clutch on manuals from high mileage or abuse

Leaking crankshaft and camshaft seals
Oil leaks from valve cover gasket & rear main seal
Failed A/C compressors on earlier cars

Corroded exhaust headers and mufflers

There are no chronic mechanical flaws or glaring weaknesses that plague either Miata NA powertrain. Just be thorough if considering a car with over 100k miles.

Given equal condition and maintenance, the 1.6L and 1.8L engines should provide many more miles of reliable fun. The community support and affordable parts keep these roadsters running well past 200,000 miles.

Driving Experience Comparison

Now that we’ve covered the technical differences, how do the 1.6L and 1.8L engines compare from behind the wheel? What’s the actual driving experience like with each motor?

1.6L Miata NA

The 116 hp 1.6L prioritizes momentum and handling precision over power. With less weight over the front axle, the chassis feels exceptionally balanced.

It remains lively and eager to rev all the way to redline. You really have to work the gears to keep it boiling in the powerband. This encourages you to focus on maintaining momentum through corners.

The lower torque does mean you have to rev it out for maximal acceleration. But the 1.6L still feels plenty zippy around town. It just lacks the muscular mid-range punch of the 1.8L.

On twisty roads, the 1.6L’s sweet handling shines through. The Miata feels like an extension of your body, perfectly poised to carve each curve. For autocross and technical courses, the 1.6L’s agility provides an edge.

In summary, the 1.6L prioritizes lightness and lively handling, rewarding a smooth driving style. While not slow, you have to rev it to unleash the full performance.

1.8L Miata NA

The key advantage of the 133 hp 1.8L engine comes down to the fatter torque curve. With an additional 14 lb-ft of twist, the Miata feels brawnier accelerating from lower RPMs.

You don’t have to constantly downshift to keep it boiling in the powerband. The extra muscle gets it up to speed quicker. Hold the throttle pinned and it still surges strongly up to redline.

The chassis feels slightly softer compared to the feathery 1.6L. But body control remains exceptional, with razor sharp turn-in when pushed. Only the most hardcore enthusiasts will notice the minor deficit in balance.

For hitting curvy backroads, the 1.8L flows from corner to corner with ease. You can be lazier with shifts and still maintain speed. And the top-end pull gives more confidence during passes.

In summary, the 1.8L adds a dose of torque while maintaining most of that signature Miata agility. The power broadens the performance envelope for casual cruising or attacking canyon roads.

Pricing Comparison

Engine	Average Used Price
1.6L	$6,500
1.8L	$7,800

Pricing based on nationwide Craigslist listings for comparable condition NA Miatas with ~120k miles. The 1.8L commands a 15-20% premium over the 1.6L driven by demand.

Pros and Cons of 1.6L vs 1.8L

1.6L Pros

Excellent handling and balance
Lower weight for agility
Eager, rev-happy powerband

Slightly better fuel economy

1.6L Cons

Less torque than 1.8L
Must rev out engine to extract power

Can feel underpowered in highway driving

1.8L Pros

More low-end and mid-range torque
Provides confident passing power

Broader powerband
Easier highway cruising

1.8L Cons

Extra weight affects handling subtlely

Not as lively at redline as 1.6L
Slightly worse fuel economy

Owner Impressions

“The 1.6L is slower but it just feels so balanced and begs to be revved. Wringing it out is part of the fun.”

“I prefer the 1.8L’s torque for daily driving. Don’t have to constantly downshift to keep up with traffic.”

“Autocrossed my 1.6L for years. The handling is so precise, it’s perfect for weaving through cones.”

“The 1.8L pulls stronger at highway speeds. Feels less strained merging and passing.”

Which Miata NA Engine is Best for You?

So given this comprehensive breakdown, should you choose the 1.6L or 1.8L for your Miata NA? Here are some key factors to help decide:

Get the 1.6L If You Want:

The lightest, most balanced handling
To rev it out and focus on momentum
An engine suited to autocross and technical courses

A roadster rewarding smoothness and precision

Get the 1.8L If You Want:

More low-end torque and power
Muscular mid-range punch for everyday driving

Confidence during highway passes and merging
A broader powerband to play in

Either engine delivers fantastic sports car fun in a reliable package. The 1.6L prioritizes agility while the 1.8L leans toward power.

For many owners, the 1.8L strikes the best overall balance of added grunt without compromising the essential Miata experience.

The extra torque broadens the car’s capabilities while still delivering nimble handling. But the lithe 1.6L satisfies those who prefer working an engine through the powerband and values momentum over might.

Conclusion

Both the 1.6L and 1.8L engines epitomize the joy of the first-gen MX-5 Miata. One is focused on lightness and momentum, rewarding smoothness. The other provides muscular torque to back up the sharp chassis.

While the 1.8L has become the preferred option, the 116 hp 1.6L shouldn’t be overlooked. It’s still lively and begs to be revved, feeling perfectly suited to technical tracks and autocross.

For many Miata fans, the NA perfectly captures the British roadster spirit of tossable handling and open-air thrills. Drivers can still enjoy near-perfect weight balance combined with just enough power for open road fun.

The NA Miata gave birth to the legendary Mazda MX-5 formula – lightweight, rear-wheel drive, near 50/50 balance matched to just enough engine. Nearly 25 years later, that original Miata magic still shines through.