MAZDA D51J-51-720 Nameplate

( Manufacturer Part Number: D51J-51-720 ), ( Genuine Oem: Yes ), ( Manufacturer Warranty: 1 Year ), ( Fitment Type: Direct Replacement ), ( Parts Included: Only Part Reference 5 On The Diagram Is Included )

Review MAZDA Genuine Nameplate fits CX-3 2021

The **Mazda D51J-51-720 nameplate** represents a rare and highly sought-after piece of automotive heritage, embodying the engineering prowess and design philosophy of Mazda during the late 1960s and early 1970s. This nameplate refers to the **1970 1972 Mazda RX-3 (first generation)**, specifically the **1.3-liter (51 horsepower) or 1.5-liter (72 horsepower) models**, depending on the market and year, with the **D51J** designation marking the inline-four engine variant. The **51-720** in the nameplate likely references the engine displacement (510cc or 720cc, though more accurately, it aligns with the **517cc** or **720cc** variants in some regional contexts) and the model s unique positioning as a lightweight, fuel-efficient sports car designed to appeal to both enthusiasts and practical drivers.

At its core, the Mazda RX-3 (D51J) was a revolutionary departure from Mazda s traditional lineup, blending Japanese precision with European-inspired styling and performance. The car s **1.3-liter (510cc) or 1.5-liter (720cc) inline-four engine** depending on the market was a product of Mazda s early experiments with overhead camshaft (OHC) technology, delivering a smooth, high-revving character that was uncommon in its time. The **D51J engine** featured a single overhead camshaft, twin SU carburetors (in later models), and a lightweight aluminum block, contributing to its compact yet robust nature. With power outputs ranging from **51 horsepower (RX-3 1.3L) to 72 horsepower (RX-3 1.5L)**, the engine was paired with a **four-speed manual transmission** (or optional three-speed automatic in some markets), allowing for spirited driving despite its modest displacement. The **720cc variant**, in particular, was a standout in its class, offering a balance of efficiency and performance that set it apart from contemporary kei cars and compact sports cars.

The RX-3 s **styling** was a bold fusion of futuristic and retro aesthetics, reflecting Mazda s ambition to create a car that felt both modern and timeless. Designed under the guidance of **Shiro Nakamura**, the RX-3 s **fastback silhouette** was inspired by European sports cars of the era, with a **long hood, short deck, and aggressive rear overhang** that gave it a presence far beyond its size. The **two-tone paint schemes**, often featuring a contrasting roof or lower body panels, added a touch of luxury and personality, while the **chrome-detailed grille, round headlamps, and sleek body lines** exuded a sense of sophistication. Inside, the cabin was minimalist yet functional, with a **bench seat (or optional bucket seats in later models), a simple but effective dashboard, and a gearshift that was both precise and engaging**. The **lightweight construction**, achieved through the use of steel and aluminum components, contributed to its nimble handling and efficient fuel consumption an impressive feat for a car of its time.

Performance-wise, the RX-3 was a **track and road-friendly machine**, capable of **0-60 mph in around 12-15 seconds** (depending on the engine variant) and a **top speed of approximately 90-100 mph**, which was remarkable for a car under **1,000 kg (2,200 lbs)**. The **D51J engine s high-revving nature** made it a joy to drive, with a **peppy throttle response** and a **distinctive exhaust note** that added to its character. The **front-wheel-drive layout** (a rarity in sports cars of the time) provided excellent weight distribution, while the **MacPherson strut suspension** and **solid rear axle** ensured a balance of comfort and responsiveness. The RX-3 was also **exceptionally fuel-efficient**, averaging **around 30-40 mpg (imperial)**, making it a practical choice for daily driving while still delivering sporty performance.

Beyond its mechanical and aesthetic merits, the Mazda RX-3 (D51J) holds a **cult following** among automotive enthusiasts for its **rare and collectible status**. Produced in limited numbers particularly the **1.5-liter (720cc) variants** these cars have become **highly desirable** over the decades, with well-preserved examples commanding **significant prices** at auctions and private sales. The **D51J nameplate** itself is a nod to Mazda s early engineering experiments, marking a transitional period where the company was pushing boundaries in both performance and design. Today, owners and collectors cherish the RX-3 for its **unique blend of nostalgia, innovation, and driving excitement**, making it a true icon of Japanese automotive history.

For those seeking a piece of this legacy, the Mazda RX-3 (D51J-51-720) is not just a car it s a **time capsule of Mazda s boldest ambitions**, a testament to the brand s ability to merge practicality with passion, and a **rare gem** that continues to captivate drivers and historians alike. Whether admired for its **engineering ingenuity, striking design, or spirited performance**, the RX-3 remains a **timeless symbol of Japanese automotive craftsmanship** and a **must-have for enthusiasts** who appreciate understated elegance and mechanical purity.

### Mazda D51J-51-720 Nameplate Overview

The Mazda D51J-51-720 refers to the engine code for the **2.5-liter inline-4 turbocharged engine** used in several Mazda models, including the **CX-5 (2017 2020), Mazda3 (2017 2020), and Mazda6 (2017 2020)**. This engine was part of Mazda s **Skyactiv-G** lineup, designed to balance performance, efficiency, and reliability. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

---

### **Pros of the Mazda D51J-51-720**

1. **Skyactiv-G Technology**

The D51J is built on Mazda s **Skyactiv-G platform**, which emphasizes high compression ratios (14:1), lightweight materials, and optimized combustion for better fuel efficiency and power output. This design reduces friction and improves thermal efficiency compared to traditional engines.

2. **Turbocharging for Performance**

The engine features a **single turbocharger** with a variable geometry turbine (VGT), delivering **184 200 horsepower and 186 lb-ft of torque** (depending on the model and year). This provides a good balance of power and efficiency, making it suitable for daily driving and light towing (up to 1,500 2,000 lbs with proper setup).

3. **Fuel Efficiency**

The D51J is one of the most efficient turbocharged engines in its class, achieving **around 20 25 MPG combined** in the CX-5 (depending on transmission and driving conditions). This is competitive with naturally aspirated engines of similar power output.

4. **Reliability and Durability**

Mazda s Skyactiv engines are known for their **robust construction**, including **forged crankshafts, high-strength cylinder heads, and a robust turbocharger**. Early reports and long-term owner feedback suggest that the D51J is **less prone to catastrophic failures** compared to some competitors (e.g., Ford EcoBoost or GM Ecotec turbo engines). However, like all turbocharged engines, it requires proper maintenance.

5. **Lightweight and Compact Design**

The inline-4 layout keeps the engine **low and centered**, improving weight distribution and handling in Mazda s front-wheel-drive and AWD models. The compact size also makes it easier to work on compared to larger V6 engines.

6. **Low Maintenance Costs**

Mazda s dealer network and aftermarket support for Skyactiv engines are well-established. Common issues (e.g., oil consumption, turbo wear) are relatively easy and affordable to address. Parts are widely available, and labor costs are often reasonable.

7. **Good for Daily Driving**

The power delivery is **smooth and linear**, with the turbo spooling up quickly but without the lag that plagued older turbo engines. This makes it suitable for commuting, highway driving, and light off-roading (e.g., CX-5 with optional AWD).

8. **Potential for Modifications**

The D51J has a **strong aftermarket support**, with options for **turbo upgrades, exhaust tuning, and fuel system enhancements**. However, modifications should be approached carefully to avoid voiding warranties or causing reliability issues.

---

### **Cons of the Mazda D51J-51-720**

1. **Oil Consumption**

One of the most common complaints is **oil burning**, particularly in higher-mileage examples. Mazda has acknowledged this issue and offered **extended warranties or buybacks** for affected engines (primarily in 2017 2018 models). Symptoms include **blue smoke from the exhaust, low oil levels, and check engine lights**. Addressing this requires **regular oil changes (every 5,000 7,500 miles) and potential valve cover or piston ring replacements** in severe cases.

2. **Turbocharger Reliability**

While the turbo is robust, **long-term turbo wear** can occur if the engine is not maintained properly. Issues like **oil starvation, carbon buildup, or turbo failure** can arise if the engine is neglected. Replacing a turbo on the D51J is **expensive ( $1,500 $2,500)** and labor-intensive.

3. **Timing Chain vs. Belt**

The D51J uses a **timing chain**, which is more durable than a belt but requires **periodic inspection** (typically every 100,000 120,000 miles). Unlike belts, chains don t need replacement but can stretch or wear, leading to timing issues if ignored.

4. **Suspension and Interior Wear**

The D51J is found in models like the **CX-5, which is known for suspension wear** (especially in off-road or aggressive driving). Bushings, struts, and control arms may need replacement earlier than expected in high-mileage examples. The interior materials (e.g., plastics, upholstery) are **budget-friendly but not premium**, which may show wear faster than in luxury competitors.

5. **Resale Value**

While not a dealbreaker, the D51J-powered Mazdas (especially the CX-5) have **moderate resale value** compared to more premium turbocharged engines (e.g., BMW B58 or Audi 1.8T). This is partly due to the engine s reputation for oil consumption and the CX-5 s position as a mid-tier SUV.

6. **Limited High-Performance Potential**

While the D51J is strong for daily driving, it is **not a high-revving or extreme performance engine**. Redlining at ** 5,500 RPM** limits its potential for serious modifications or track use. For enthusiasts seeking **high horsepower**, other Mazda engines (e.g., the **SKYACTIV-R 2.0T in the MX-5 or CX-5 Turbo**) may be better choices.

7. **Early Model Teething Issues**

Some **2017 2018 models** had **software or calibration issues**, leading to rough idling, stalling, or reduced power. Mazda addressed these through **firmware updates**, but buyers should ensure the vehicle has received all updates.

8. **Towing Limitations**

While the D51J can handle **light towing (up to 1,500 2,000 lbs)**, it is **not designed for heavy towing**. Mazda s **official towing capacity** for the CX-5 with this engine is **1,500 lbs**, and exceeding this can strain the engine and transmission.

---

### **Conclusion**

The Mazda D51J-51-720 is a **well-engineered, efficient, and reliable turbocharged engine** that excels in daily driving applications. Its **Skyactiv-G architecture** provides a strong balance of power, fuel economy, and durability, making it a **solid choice for buyers who prioritize practicality and longevity**. However, **oil consumption and turbocharger reliability** are critical factors that require **diligent maintenance** to avoid costly repairs.

- **Prioritize fuel efficiency and low operating costs**,

- **Want a smooth, turbocharged engine for commuting or light adventure**,

- **Are willing to monitor oil levels and address minor wear items proactively**,

the D51J is an **excellent and undervalued option**, especially in models like the **CX-5 or Mazda3**.

- **Plan to tow heavily or modify the engine aggressively**,

- **Are sensitive to oil burning or turbo issues**,

- **Seek a high-revving or performance-focused engine**,

alternative engines (e.g., the **SKYACTIV-R 2.0T, Ford EcoBoost, or Toyota 2.0T**) may be more suitable.

---

### **Recommendation**

- You are looking for a **reliable, efficient, and low-maintenance turbocharged engine** for daily use.

- You **inspect the vehicle thoroughly** for oil consumption issues (check for blue smoke, low oil levels, or service records).

- You **commit to regular oil changes (every 5,000 7,500 miles)** and basic maintenance (e.g., air filter, spark plugs).

- You prefer **Mazda s Skyactiv technology** for its balance of performance and efficiency.

- The vehicle has **high mileage (>120,000 miles) without proper maintenance records**.

- You **plan to tow frequently or heavily** (consider a more robust engine).

- You **intend to modify the engine significantly** without proper tuning and support.

- **Mazda CX-5 (2017 2020)** Ideal for AWD daily drivers and light off-roading.

- **Mazda3 (2017 2020)** Great for hatchback buyers who want turbo power without sacrificing efficiency.

- **Mazda6 (2017 2020)** A solid choice for sedan buyers who want a refined turbo engine.

The D51J

Details:

Shipping Carrier substitutions may be made at our determination in an attempt to reduce shipping cost the customer. Electrical parts are not returnable. Parts must be resalable and in the original packaging.

part #: d51j51720 prices

• $19.64-$52.33

specifications emblico:

• for models: Cx-3
• for makes: Mazda
• for years: 2021
• mpn: D51j-51-720
• genuine oem: Yes
• manufacturer warranty: 1 Year
• fitment type: Direct Replacement
• parts included: Only Part Reference 5 On The Diagram Is Included

shipping emblico:

• cost: $20.52
• service: Standard
• transit: 4-7 Days
• class: Standard
• type: Fixed

returns emblico:

• policy: Returns Accepted
• time: 30 Days
• paid by: Seller

seller emblico:

• # reviews: 1088
• rating: 99.3%
• city: Port Charlotte, Florida

payments emblico:

• credit card: Diners-club
• wallet: Apple-pay
• other

general emblico:

• Car Truck Parts Accessories > Exterior Parts Accessories > Emblems Ornaments
• condition: New

offer emblico:

• availability: In Stock
• started: March 21, 2026
• options: Ship-to-home
• quantity: 4
• sold: 0

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