Mazda cars with 2.5 SkyActiv G engine “This engine is installed on the Mazda CX-5, Mazda 6 and Mazda 3” are very popular with buyers because of their excellent performance and affordable prices. The current generation of these cars is very technological, stylish and dynamic, equipped with a powerful engine and very reliable.
Modern Mazda engines are small in volume, but thanks to the use of modern technology, they provide excellent power and excellent efficiency characteristics. This is a modern high-tech 2.5 liter engine that appeared in the proposal of the Japanese automaker in 2011. In fact, it is one of the first representatives of a new generation of Skyactiv engines.
Mazda 2.5 SkyActiv Engine Reviews
These power units replaced the 4 and 6 cylinder engines with volumes of 2.3 and 2.5 liters. While most car makers today are increasing the power of their engines by installing turbines, which always leads to a decrease in engine reliability, Mazda has taken a different path. Engineers at this Japanese car manufacturer have maximized the compression ratio of the fuel in their engines. The 2.5 liter unit has a compression ratio of 14 units. This is one of the atmospheric engine record figures.
This modification of the power unit is distinguished by the presence of a hydraulic lift, a variable valve timing system mounted on both shafts at once, innovative injection and an original piston shape. All this makes it possible to significantly improve the performance of the engine, reduce its vibration, while ensuring the maximum power of the power unit and excellent efficiency.
From the characteristic features of this engine, we can note its operation at 95 petrol, which distinguishes it well against the background of many modern power units that require the use of exclusively high-octane fuel.
The four-cylinder, 16 valve engine is made of aluminum and has excellent heat resistance. Thanks to the use of modern technology with a volume of 2.5 liters, 192 horsepower is obtained from this naturally aspirated engine. With this power, the engine shows excellent efficiency.
Mazda 2.5 SkyActiv Compression Ratio and Piston
The most basic change has to do with increasing the compression ratio, in 2.5 Skyactiv-G the value is “14” – that’s a lot! Because in ordinary gasoline engines only “10, maximum 12 units” (for comparison, in MZR2.0 – “10”).
What does such a high compression ratio provide? Yes, everything is simple – temperature and pressure rise in the cylinder (at the end of the compression stroke), due to which Efficiency, power increases, fuel consumption decreases.
As confirmed by the manufacturer – this engine has 15% more torque, and is also 30% more efficient than the old unit.
However, with enormous compression (for gasoline), there are big negative moments. It is an explosive ignition of the fuel mixture, in which the rings, as well as the entire piston group as a whole, suffer.
First, it changes the shape of the piston itself – it resembles a trapezoid (protrudes upwards, often a normal piston is just flat), but in the center there is a small indentation. It is made to form a uniform ignition mixture near the spark plug, with uniform ignition of the piston occurring, which reduces explosion.
Mazda 2.5 SkyActiv Problems & Reliability
- When the 2.5 SkyActiv engine is hot, visible vibrations are recorded.
As an alternative, we can recommend that you replace the high voltage coil. They fail quite often, have an affordable cost and change as a set. You will need 4 high voltage coils to solve the fine jitter problem at idle.
- The 2.5 SkyActiv engine loses power and fuel consumption increases.
Check the condition of the fuel system and injectors. 2.5 Skyactiv such problems are common with injectors, which become clogged when using low quality fuel. Comprehensive machine diagnostics need to be done.
- Insufficient oil pressure alarm appears.
In this case, stop driving, check the oil level and, if necessary, add lubricant to the engine. If the warning signal does not disappear, you will need to turn off the engine and bring the car to service in a tow truck. The technician at the repair shop will open the machine and determine the cause of the problem.
- The appearance of a rustling sound at low engine speed.
The appearance of such a sound indicated an extended time chain. You will need to open the engine, inspect the engine and replace the drive chain if necessary.
- You can use a suitable tuning of the chip, which involves flashing the control unit and removing the catalyst. This setup option doesn’t cause any difficulties and is performed in most dedicated setup offices. You can also install additional chips yourself, which will increase the efficiency of the power unit. As a result, it turns out that this power has increased to the level of 210 horsepower.
- It is possible to install a turbine, but it will be necessary to redo the ShPG (connecting rod piston group), which in turn leads to a decrease in the reliability indicator and the loss of all Skyactiv engine technology.
- Despite extensive use, these engine are reliable and durable. Car owners only need to carry out maintenance on time, including regular oil changes.
Mazda 2.5 SkyActiv Maintenance
The manufacturer recommends 2.5 Skyactiv doing such work every 15,000 kilometers. However, in reality, to ensure proper lubrication and cooling of the power unit and when operating the car especially in the city, it is best to change the oil every 7,500 kilometers.
From service work, we also noted the need to open the engine with a rotation of 75,000 kilometers. With such a run the first problems with timing can be noted. It is chained and, according to the automaker, maintenance free.
However, after 75,000-100,000 kilometers of running and operating the car in difficult conditions, 2.5 Skyactiv problems with chains can be noted, which are stretched and require adjustment or replacement. That is why it is still not advisable to neglect servicing and refurbishing cars on a 100,000 kilometer run.