Are All Subaru WRXs Turbocharged? (And Do They All Require Premium Gas?)

All Subaru WRX models (which stands for World Rally eXperimental) are turbocharged and have been ever since the genesis of this rallying-inspired Subaru model's first generation in 1992. A turbocharger is an exhaust-driven compressor that feeds the engine larger volumes of intake air. When combined with additional fuel, this produces higher power levels than would normally be possible with a naturally aspirated version of the same engine. 

Turbocharging of performance cars became popular in the 1980s, thanks to engineering achievements related to turbo boost controls, intercooling development, and improved turbo metallurgy.  

Subaru had started with its Symmetrical All-Wheel Drive system and its flat-four engine, which already had a very low center of gravity. Тhen, it took its Impreza and added a turbocharger to boost the engine's power, thus making the Subaru WRX different from the Impreza. 

As a result, the Subaru WRX, along with its higher-powered WRX STI sibling, in itself the basis for Subaru's factory rally cars, became a force to be reckoned with in the World Rally Championship. Subaru went on to win three manufacturer's championships in a row, making it the first Japanese carmaker to ever achieve this feat. 

According to Subaru, performance models, including the Subaru WRX, WRX STI, and BRZ, all require premium, and will state this on a label located near the gas filler. The WRX owner's manual states that "The engine is designed to operate using unleaded gasoline with an octane rating of 91 or higher." 

If you're unable to find fuel of 91 octane or higher, you can use a lower octane fuel, as long as it is at least 87 octane. The lower-octane fuel will not harm your WRX's turbocharged engine. The WRX STI models require higher octane unleaded gas that is at least 93 octane.

The reason that the low-octane fuel won't hurt your car is because modern engines have very sophisticated computer controls that can sense when you have lower-octane fuel in a car that was designed to run on premium. When this happens, the computer can adjust the ignition timing to prevent any potential issues from occurring. 

The only downsides of this adjustment are reduced performance on the low-octane fuel, as well as poorer fuel economy while your engine is consuming it. If you have any questions about the recommended fuel required for your Subaru WRX or any other vehicle, please check your owner's manual for all the necessary information.

There have been five generations of the Subaru WRX. The first generation, built on the compact Impreza platform, was made from 1992 until 2000 and not sold in North America. The WRX initially produced 237 horsepower from its turbocharged flat-four, escalating to 300 hp in the WRX STI versions of the car. 

The second WRX generation was made from 2000 until 2007 and was the first version exported to the U.S., arriving here for the 2002 model year. Its 2.0-liter flat-four was turbocharged, as per the WRX formula, and put out 227 horsepower. A wagon body was also available on the WRX, and the higher powered STI version was also available. 

The third WRX generation was on the market from 2008 through 2014. Initially available only as a five-door hatchback, a sedan body style was added later. Performance aspects were somewhat lackluster and dumbed-down at first, but by its later years, the balance of power was restored. The 2009 WRX with a manual transmission produced 265 horsepower, while the WRX STI was rated at 305 hp in 2014. 

The fourth generation WRX ran from 2015 to 2021, and was no longer built on the Impreza platform, though they did share some parts. Its flat-four turbo now produced 268 horsepower, with the STI putting out the same 305 hp as before. The fifth generation Subaru WRX, available from 2022, has received a power boost to 271 horsepower, while the STI is discontinued. The WRX can be identified by its controversial black plastic fender trims.