Subaru’s signature growling boxer four-cylinder WRX engine has been rumbling U.S. roads for nearly two decades. What has changed over the years?
The Subaru WRX and its engine are legendary parts of everyday driving as much as they are an iconic part of motorsports. You can not bring up any aspect of rally racing without discussing the legendary Subaru WRX. Furthermore, you’d be hard-pressed to make an appearance at any sort of car meet or club and not run into a WRX.
While their World Rally Championship-winning heritage and world-class all-wheel-drive system are definitely points to be discussed, one thing stands out to even those who don’t know the rally heritage of the WRX: the low, angry rumble of the Subaru flat four-cylinder boxer engine. It’s instantly recognizable and familiar to most car enthusiasts.
Like a Porsche engine, the WRX (and most other Subarus) use a flat engine layout (meaning the pistons go side to side rather than up and down).
The WRX and Subaru were a dominant force in rally in the ’90s and early-2000s. With driver Colin McRae heading the Subaru World Rally Team and collecting championship wins, demand for the road-going version of the turbocharged all-wheel-drive warrior continued to grow.
Though the Subaru WRX had previously existed for other markets, the U.S. did not get the rally car for the road until 2002. However, despite its controversial front-end design, the WRX was an instant hit in America.
Since its debut, the WRX and the signature sound of its boxer engine have grown in popularity. Let’s take a look at the different generations of the WRX and the specs of the engines available in them.
Subaru WRX Generations & Engines: U.S. Release
Second Generation Subaru WRX (2002-2003)
The first version of the WRX available here in the United States came with the model year 2002 Subaru Impreza. This is the second-generation Subaru Impreza and the first design of three throughout the generation. It is known as the “bug-eye” due to its round headlights.
The bug-eye WRX has a 2.0-liter turbocharged boxer four-cylinder engine, known internally as the EJ20. The EJ20 in the bug-eye makes 227 horsepower and 217 lb.-ft. of torque. Though not the most efficient, the bug-eye WRX does have EPA ratings of 18 mpg city and 25 mpg highway.
Second Generation Subaru WRX Facelift (2004-2005)
The first major change in the U.S.-delivered variants of the Subaru WRX came with the facelift of the 2004 Subaru Impreza. While the front-end redesign is substantial, the biggest change here is the addition of the STI model to the WRX.
The STI is the more track and/or racing-oriented version of the WRX. The STI has more aggressive suspension, more horsepower, and a six-speed manual transmission instead of a five-speed.
This facelift is known as the “blob-eye” WRX, and it maintains the EJ20 with the same power output at 227 horsepower and 217 lb.-ft. of torque, just like the bug-eye. It also sees fuel economy ratings up to 20 mpg city and 27 mpg highway.
The STI, however, gained a significant jump in power. This comes courtesy of a bump in displacement to 2.5-liters. This bigger variant of the same boxer engine is known as the EJ25. The EJ25 in the 2004 WRX STI makes 300 horsepower and 300 lb.-ft. of torque. Of course, the extra power comes at the cost of fuel economy, as the STI sees up to 18 mpg city and 24 mpg highway.
This isn’t the final stop for this generation of the WRX, either.
Second Generation Subaru WRX Facelift (2006)
The second generation got one more facelift with the model year 2006 Subaru Impreza. This change once again brought on a new nickname: “Hawkeye.”
For the Hawkeye, both the WRX and WRX STI remain available. However, the WRX got an upgrade and would now come standard with a slightly watered-down version of the EJ25 found in the blob-eye STI. Furthermore, the STI is also equipped with an EJ25.
The EJ25 engine has a power output of 230 horsepower, giving it only a three-horsepower advantage over the previous EJ20. However, the torque sees a significant increase to 235 lb.-ft. Still equipped with a five-speed manual, this generation WRX sees fuel economy ratings up to 20 mpg city and 26 mpg highway.
The STI also retains the power from the previous facelift at 300 horsepower and 300 lb.-ft. of torque. Additionally, fuel economy ratings remain the same at 18 mpg city and 24 mpg highway.
Third Generation Subaru WRX (2007-2014)
The third-generation WRX finally arrived with the model year 2007 Subaru Impreza. Meant to be more mainstream and user-friendly, the WRX grew a bit in size and lost a little bit of its raw driving feeling in place of more comfortable everyday suspension.
The third-gen WRX retains the EJ25 from the previous gen. In 2007 and 2008 models, the WRX has 224 horsepower and 226 lb.-ft. of torque. However, the 2009 Subaru WRX got a refined version of the EJ25 that bumps power figures up to 265 horsepower and 244 lb.-ft. of torque. This new power output took a toll on the economy, though, as it now has 18 mpg city and 25 mpg highway ratings.
The third-gen WRX STI and its version of the EJ25 also saw an increase in power to 305 horsepower.
Unfortunately, though, torque did drop to 290 lb.-ft. Fuel economy ratings for the third-gen STI are up to 18 mpg city and 25 mpg highway.
With the end of the third-generation WRX also came the end of the legendary rally-inspired care coming paired with the legendary EJ engine.
Fourth Generation Subaru WRX (2015-Present)
Just like with the last generation, the WRX took a turn to more run-of-the-mill standards with the 2015 model year. However, the WRX and WRX STI became their own model, dropping the name Impreza. Though they share the platform with the standard Impreza, the WRX and WRX STI have a much more aggressive styling outlook.
However, the biggest shift for the fourth-gen models, as we mentioned before, is the distinct lack of an EJ engine under the hood. That being said, the familiar boxer flat-four layout remains the same.
Instead of an EJ, the FA20 engine took over for the WRX family. This is the same engine framework found in the Toyota 86, Subaru BRZ, and Scion FR-S. Though, those models do not come turbocharged.
The fourth-gen WRX and its FA20 come standard with 268 horsepower and 258 lb.-ft. of torque. It has an EPA fuel economy rating of 20 mpg city and 27 mpg highway.
The fourth-gen WRX STI has 305 horsepower and 290 lb.-ft. of torque. It gets an EPA estimated 17 mpg city and 23 mpg highway.
Subaru WRX Engine Reliability
Is a Subaru WRX engine reliable? Unfortunately, the truthful and straightforward answer is; not really.
The EJ20 found in earlier WRX examples are about the least problematic of the two older generations of the WRX delivered to the U.S. However, they are still subject to rod bearing and head gasket failures. Especially with high mileage, it is important to maintain clean oil at a proper level. Most importantly, though, is not to push the engine too hard.
While it is amazing to watch WRXs fly around a rally stage, it is important to remember they have a trailer full of spare parts and big budgets backing up any accidents. If you blow the engine on your daily driver, you are not likely to have it back up and running in the same timeframe that they will.
The EJ25 is the most problematic WRX engine of them all. Unfortunately, they are so unreliable and prone to premature failure that WRX and WRX STI owners brought a class-action lawsuit against Subaru. The lawsuit alleges that the EJ25 has faulty rod and crankshaft bearings prone to failure long before the reasonably expected lifespan of an engine. This lawsuit explicitly cites WRX and WRX STI models from 2009 to 2014.
However, earlier variants of the EJ25 are prone to similar failures, and failures of the ring lands on the pistons. Any of these failures can lead to thousands of dollars in repairs and may even necessitate a complete replacement of the engine. The lawsuit was settled with Subaru agreeing to pay owners who had to pay for repairs as well as extend the affected vehicles’ warranties to a period of eight years and 100,000 miles.
Engine Reliability Issues
Unfortunately, the newest generation of the WRX and WRX STI equipped with the FA20 boxer engine is not in much better of a position. Currently, owners have given them an average reliability rating of just two out of five.
Like the EJ series engines, the FA20 engines in the fourth-gen WRX and WRX STI models are experiencing connecting rod failures. But most of these failures are coming due to modifications like aftermarket tunes and additional power.
While this may not be much of a worry when driving a stock WRX or WRX STI, many shoppers interested in these cars like them for their ability to be modified quite easily. So, this is something to watch out for if you’re shopping for a WRX or WRX STI to add power to or take racing.
Another issue some owners report with the FA20 equipped models is poorly mapped factory tunes. They claim that the tunes are too aggressive and run too lean, which means there is not enough fuel for the amount of air going into the engine. This can cause detonation issues that result in connecting rod failure.
As with any car, owners can avoid many issues associated with the FA20 engine entirely by driving it sensibly. But, when the car is inspired by actual rally cars, it makes it a little difficult to keep yourself from wanting to open it up and see what it can do.
Should You Buy a WRX?
Despite the well-documented issues associated with the Subaru WRX engines of all generations, they still have a cult following of fans who drive them every single day. As with any car, proper maintenance and reasonable driving go a long way in keeping a WRX alive.
That’s why, when shopping for a used car, we highly recommend running a vehicle’s VIN through our free VIN research tool to get its complete detailed history.
Furthermore, finding a well-maintained car with repair and service records is imperative when buying a car like this if you plan to use it every day. Nobody wants to hear that a car they are interested in buying is unreliable, but it is important to know what you’re getting yourself into before buying.
Despite their issues, the Subaru WRX is a fantastic experience of a car to drive. However, owners and potential buyers have to keep in mind that they are a bit more high-maintenance than your run-of-the-mill economy car.
Photos: Subaru, Wikipedia Commons: OSX; IFCAR
