Mazda 1.5 SkyActiv-G Engine Specs, Problems, Reliability, Info

Mazda 1.5L Skyactiv-G Engine Info

The SkyActiv-G 1.5, also known as the P5-VPS, is a 1.5-liter, four-cylinder, naturally aspirated gasoline engine with direct fuel injection. This motor is part of Mazda's SkyActiv engine family. The SkyActiv series features a range of automotive technologies developed by Mazda that enhance fuel efficiency and engine performance. The 1.5-liter version was introduced in the Mazda3 (Mazda Axela) and Mazda2 (Mazda Demio) in 2014, replacing the previous 1.5 and 1.6-liter MZR engines. A few years later, it became available for the fourth-generation Mazda MX-5 (P5-VP or PR-VP RS engine for RWD applications). At present, this engine is widely used in both Asia and Europe. So let's take a look at the 1.5 SkyActiv-G engine design, its features, issues, and reliability.

Skyactiv-G 1.5 Design and Features

The Skyactiv 1.5 engine features a lightweight aluminum cylinder block, with a bore of 74.5 mm (2.93 in) and a stroke of 85.8 mm (3.38 in), resulting in a capacity of 91.3 cu in (1496 cc). Engines for FWD applications goes with a more common cast iron crankshaft inside, while all MX-5 engines have a more sturdy steel crankshaft to hold higher RPMs (redline is 7500 rpm). On top of the block, there is a 16-valve aluminum cylinder head with two chain-driven camshafts and roller rocker arms. It also has a Dual Sequential Valve Timing System (or Dual S-VT). The main feature of this engine is the combination of direct fuel injection and a very high compression ratio (13 to 1 or 14 to 1, depending on power output). Fuel injection is provided by special, electronically controlled, six-hole injectors that inject fuel directly into the combustion chambers. This type of injection requires a high-pressure fuel pump. It is mounted on the cylinder head and is driven by the exhaust camshaft.

It is also worth noting the unique shape of the intake ports, which helps to create a vortex effect within the combustion chamber. This effect provides a more uniform air-fuel mixture and more efficient combustion, resulting in better performance. All engines in the SkyActiv series have a 4-2-1 exhaust system, and the 1.5-liter model is no exception. The engine is equipped with a strangely shaped 4-2-1 exhaust header with long runners that lead to the catalytic converter (it is all one piece).

Engine Specs

The Most Common Problems

The 1.5 SkyActive-G engines are a small and reliable engine by modern standards. But at the same time, it is a very complicated motor, in which many things can fail.

• Spark plugs do not last very long on this engine, and ignition coils are also prone to failure, which can be expensive to repair.
• Direct injection requires premium gas. Using low-quality fuel can easily damage injectors, ignition coils, and the high-pressure fuel pump.
• Carbon build-up is a common problem for most GDI engines. Carbon accumulates inside the intake ports and, at some point, can lower the performance of the engine, its efficiency, and overall longevity.
• This engine features an electronic coolant control valve, instead of a traditional mechanical thermostat. This unit often has reliability issues.
• Even low-mileage engines may consume some oil. However, the engine oil consumption typically does not increase significantly with age.

Skyactiv-G 1.5 Reliability and Longevity

So is the Mazda 1.5 Skyactiv engine any good? Yes, it is a durable and reliable engine with plenty of power for its size. Like all modern engines filled with complex systems, it requires good care, high-quality fuel and oil. The average lifespan of this Japanese engine is around 150,000 miles (250,000 km).

Modifications

P5-VP (RS) - 131 hp (96 kW) / 7,000 rpm, 111 lb-ft (150 Nm) / 4,800 rpm - special version for Mazda MX-5 model. This engine has a steel crankshaft, as mentioned earlier, and light rotating parts, as well as different cam timing. The intake system has also been modified. It includes a variable-length intake manifold that increases power and torque by reducing the length at high engine speeds. Thanks to these modifications, the redline of the engine has been raised to 7,500 RPM.