For enhanced safety, the front seat shoulder belts of the Subaru WRX are height-adjustable to accommodate a wide variety of driver and passenger heights. A better fit can prevent injuries and the increased comfort also encourages passengers to buckle up. The BMW M3 doesn’t offer height-adjustable seat belts.
The WRX has all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The M3 doesn’t offer all-wheel drive.
To help make backing safer, the WRX Limited’s optional cross-path warning system uses wide-angle radar in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The M3 doesn’t offer a cross-path warning system.
Both the WRX and the M3 have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, available crash mitigating brakes, lane departure warning systems and blind spot warning systems.
For its top level performance in all IIHS frontal, side, rear impact and roof-crush tests, and with its optional front crash prevention system, the Insurance Institute for Highway Safety grants the WRX its highest rating: “Top Pick Plus” for 2015, a rating granted to only 64 vehicles tested by the IIHS. The M3 has not been tested, yet.
Subaru’s powertrain warranty covers the WRX 1 year and 10,000 miles longer than BMW covers the M3. Any repair needed on the engine, transmission, axles, joints or driveshafts is fully covered for 5 years or 60,000 miles. Coverage on the M3 ends after only 4 years or 50,000 miles.
There are over 67 percent more Subaru dealers than there are BMW dealers, which makes it much easier should you ever need service under the WRX’s warranty.
The flat cylinder configuration of the boxer engine in the WRX lowers its center of gravity, enhancing handling stability (That’s why Porsche uses boxer engines.). The M3 doesn’t offer a boxer engine configuration.
The WRX STI handles at .99 G’s, while the M3 pulls only .98 G’s of cornering force in a Road & Track skidpad test.
For better maneuverability, the WRX’s turning circle is 4.6 feet tighter than the M3’s (35.4 feet vs. 40 feet). The WRX Premium/Limited/STI’s turning circle is 4 feet tighter than the M3’s (36 feet vs. 40 feet).
The Subaru WRX may be more efficient, handle and accelerate better because it weighs about 150 to 250 pounds less than the BMW M3.
The WRX is 3 inches shorter than the M3, making the WRX easier to handle, maneuver and park in tight spaces.
As tested by Car and Driver, the interior of the WRX is quieter than the M3:
The WRX has 1.3 inches more front legroom and .3 inches more rear legroom than the M3.
The WRX Auto offers a remote vehicle starting system, so the vehicle can be started from inside the driver's house. This allows the driver to comfortably warm up the engine before going out to the vehicle. The climate system will also automatically heat or cool the interior. The M3 doesn’t offer a remote starting system.
In case you lock your keys in your vehicle, or don’t have them with you, you can let yourself in using the WRX Limited/STI’s available exterior keypad. The M3 doesn’t offer an exterior keypad entry system, and its BMW Assist can’t unlock the doors if the vehicle doesn’t have cell phone reception or the driver can’t contact the service.
To shield the driver and front passenger’s vision over a larger portion of the windshield and side windows, the WRX Limited Auto offers optional extendable sun visors. The M3 doesn’t offer extendable visors.
To keep a safe, consistent following distance, the WRX Limited Auto offers an optional Adaptive Cruise Control, which alters the speed of the vehicle without driver intervention. This allows the driver to use cruise control more safely without constantly having to disengage it when approaching slower traffic. The M3 doesn’t offer an adaptive cruise control.
Insurance will cost less for the WRX owner. The Complete Car Cost Guide estimates that insurance for the WRX will cost $1845 to $7025 less than the M3 over a five-year period.
The WRX will cost the buyer less in the long run because of its superior resale value. Kiplinger’s estimates that the WRX will retain 44% to 52% of its original price after five years, while the M3 only retains 42%.
Intellichoice estimates that five-year ownership costs (depreciation, financing, insurance, fuel, fees, repairs and maintenance) for the Subaru WRX will be $14879 to $31575 less than for the BMW M3.
The Subaru WRX won three awards in Kiplinger’s 2015 car issue. The BMW M3 didn't win any award.
J.D. Power and Associates rated the WRX second among compact cars in owner reported satisfaction. This includes how well the vehicle performs and satisfies its owner’s expectations. The M3 isn’t in the top three.
The WRX is ranked first in its class and received the 2015 “Total Quality Award.” The M3 is not ranked.
The WRX was chosen as one of Automobile Magazine’s “All Stars” for 2 of the last 13 years. The 3 Series hasn’t been picked since 2014.