The Mazda MX-5 ND (Mk4) was widely considered a return to form at introduction: it’s smaller, lighter, and sharper than the NC. It remains one of the best value driver’s cars, however since the oldest models are now over a decade old, there are specific things you need to watch out for.
1. The Choice: Soft Top vs. RF (Retractable Fastback)
The ND comes in two distinct body styles. Your choice depends on how you plan to use the car.
| Feature | Classic Soft Top (Roadster) | RF (Retractable Fastback) |
|---|---|---|
| Roof Action | Manual (one-handed, ~3 seconds). | Electric (targa-style, ~13 seconds). |
| Look | Classic silhouette; completely open air. | Sleek “fastback” look; targa-top opening. |
| Weight | Roughly 50kg lighter than the RF. | Heavier, with a slightly higher center of gravity. |
| Refinement | More wind noise; more “connected” to the road. | Quieter with the roof up; better for motorways. |
| Boot Space | 130 Litres (standard). | 127 Litres (slightly smaller due to roof storage). |
Get the Soft Top if you want the purest driving experience. The RF may suit more if this is your daily driver and you do frequent motorway miles or you have security concerns, the extra soundproofing and “coupe” security make a difference in British winters.
2. Engine & Performance: 1.5 vs. 2.0
| Model & Engine | Redline (RPM) | Power (PS / BHP Approx) | Character |
|---|---|---|---|
| ND1 1.5L (2015–2018) | 7,500 | 131 PS / 129 BHP | Highly “revvy”; requires constant gear changes to keep it singing. |
| ND1 2.0L (2015–2018) | 6,800 | 160 PS / 158 BHP | Punchier at low speeds, some say it feels “strangled” at the top end. |
| ND2/3 1.5L (2018–Present) | 7,500 | 132 PS / 130 BHP | Virtually identical to the ND1, just slightly refined for emissions. |
| ND2/3 2.0L (2018–Present) | 7,500 | 184 PS / 181.5 BHP | Mazda raised the rev limit by 700rpm. It now feels as eager as the 1.5 but with significantly more “shove.” |
PS vs. BHP
When browsing listings, you’ll see power quoted in both PS and BHP. They are very similar, but not identical.
- PS (Pferdestärke): This is the metric “horsepower” used by German and European manufacturers.
- BHP (Brake Horsepower): The imperial measurement standard in the UK.
- Conversion: 1PS is approx 0.986BHP.
3. What to Check Before You Buy
Water Ingress & Roof Drains
In the UK, dampness is the MX-5’s greatest enemy.
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Feel the carpets in the footwells and behind the seats. If they’re damp, the roof drain filters are likely blocked with leaves or road grime.
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If water pools in the cabin it can cause electrical gremlins in the ECU and sound system..
The “Roof Rub” (Soft Top Only)
On some soft tops, the roof material can rub against the plastic roll-hoop covers when folded down, leading to premature wear or holes.
- Fold the roof down and see if there is a gap between the fabric and the plastic hoops. Many owners fit spacers or “bump stops” to prevent this.
Suspension & Rust
While the ND has more aluminium and high-tensile steel than earlier models, road salt still takes a toll.
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Inspect the rear subframe and suspension arms for surface corrosion. It’s rarely structural yet, it is worth getting it undersealed once you buy it.
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Alloy Wheels: Mazda’s OEM “Gunmetal” finish can exhibit “bubbling” or peeling. Check for corrosion around the centre caps.
Spherical Bearing Problem
The spherical bearing problem (often incorrectly referred to as spherical bushes) is one of the most common mechanical headaches for ND owners. It refers to the premature failure of two specialised bearings located within each rear hub carrier (also known as the rear knuckle).
The issue is caused by the rubber seals on these bearings. In the UK’s wet and salty climate, the seals perish or split, allowing water and road grit to enter the bearing.
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The lubrication washes out.
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The metal-on-metal joint begins to corrode and wear down.
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Eventually, the joint develops “play” (movement), which ruins the car’s precision and creates noise.
This problem primarily affects the ND1 (2015–2018), but it has been reported on early ND2 (2019) models as well. Mazda reportedly made improvements to the seals on more recent cars though it is worth keeping an eye on them.
When you are test-driving a used ND, keep your ears open for:
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The “Clunk”: A distinct metallic knocking or rattling from the rear when going over speed bumps, potholes, or uneven road surfaces.
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Vibration: A strange “buzz” or vibration felt through the seat at motorway speeds.
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Rear-End Wander: On a straight road, the car might feel slightly “loose” or like it’s self-steering from the rear (this is because the play in the bush is changing the wheel’s alignment as you drive).
If you find a car you love but it has this issue, don’t panic. The aftermarket has developed solutions which are significantly cheaper than replacing the whole hub carrier.
- Individual Replacement Bearings: Various companies now sell replacement spherical bearings specifically for the ND hub.
Buying Tip:
When inspecting a car, look through the spokes of the rear wheels with a torch. If you see orange/brown rusty staining weeping from the rubber boots on the rear hub, the bearings are likely on their way out.
Window Regulator Failures
Another thing to look for involves the power window regulators, which are prone to failure due to internal corrosion. The design features a steel cable housed within a plastic guide; over time, water seeps into the door cavity and gets trapped inside the cable housing. Because the cable doesn’t always have sufficient grease, it rusts, frays, and eventually snaps.
Listen for a “crunching” or “grinding” sound when the window moves, or notice if the glass seems to travel slower than usual. If the window “drops” into the door and won’t come back up, the cable has likely snapped.
During a test drive, cycle both windows up and down multiple times. They should move smoothly and quietly.
- Many owners proactively spray a lithium-based grease or silicone lubricant into the window tracks and onto the regulator assembly (accessible by removing the door card) to ward off the dreaded crunch.
Replacement regulators are not expensive however care needs to be taken when replacing them not to inadvertently ‘unwind’ it.
There may have been a component update in more recent cars, time will tell whether this continues to be an ongoing issue.
4. Trim Levels to Look For
In the UK, the trims have evolved over time, but generally:
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SE / SE-L: The base/mid trims.
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Sport / Sport Nav: 2.0L models in this trim usually come with Bilstein dampers, a Limited Slip Differential (LSD), and a front strut brace.
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Special Editions: Look for the 30th Anniversary (Racing Orange) or the Homura for Brembo brakes and Recaro seats.
Buying Tips Summary
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Check the Drains: Always check for dampness. If the car smells “musty,” walk away.
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Service History: Ensure it has had annual oil changes, even with low mileage.
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Tyres: The ND is very sensitive to tyre choice. If it’s on mismatched “budget” rubber, it’s a sign the owner might have skimped on maintenance. A set of good quality matched tyres is a positive sign.
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Check the spherical bearings, look through the spokes of the rear wheels with a torch. If you see orange/brown rusty staining weeping from the rubber boots on the rear hub, the bearings are likely on their way out.
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Check the window operation is smooth on both sides, if not the window regulators may be failing.
Please PM any suggestions for additions or edits, this is an information post rather than a discussion topic.