For enhanced safety, the front seat shoulder belts of the Mitsubishi Eclipse Coupe 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 3 Series Coupe doesn’t offer height-adjustable seat belts.
Both the Eclipse and the 3 Series Coupe have standard driver and passenger frontal airbags, front side-impact airbags, front seatbelt pretensioners, four wheel antilock brakes, traction control and electronic stability systems to prevent skidding.
The Eclipse comes with a full 5 year/60,000 mile basic warranty, which covers the entire car and includes 24 hour roadside assistance. The 3 Series Coupe’s 4 year/50,000 mile basic warranty expires 1 year and 10,000 miles sooner.
Mitsubishi’s powertrain warranty covers the Eclipse 6 years and 50,000 miles longer than BMW covers the 3 Series Coupe. Any repair needed on the engine, transmission, axles, joints or driveshafts is fully covered for 10 years or 100,000 miles. Coverage on the 3 Series Coupe ends after only 4 years or 50,000 miles.
There are over 69 percent more Mitsubishi dealers than there are BMW dealers, which makes it much easier to get service under the Eclipse’s warranty.
The Mitsubishi Eclipse’s engines use a cast iron block for durability, while the 3 Series Coupe’s engines use an aluminum block. Aluminum engine blocks are much more prone to warp and crack at high temperatures than cast iron.
The engines in the Eclipse have a single overhead cam for simplicity. The engines in the 3 Series Coupe have dual overhead cams, which add to the number of moving parts and the complexity of the cylinder heads.
To lower fuel costs and make buying fuel easier, the Mitsubishi Eclipse uses regular unleaded gasoline (premium recommended on Eclipse GT for maximum performance). The 3 Series Coupe requires premium, which can cost 20 to 55 cents more per gallon.
The Eclipse has 1.6 gallons more fuel capacity than the 3 Series Coupe (17.7 vs. 16.1 gallons), for longer range between fill-ups.
For better traction, the Eclipse has larger tires than the 3 Series Coupe (235/45R18 vs. 225/45R17). The Eclipse’s tires are larger than the largest tires available on the 3 Series Coupe (235/45R18 vs. 225/40R18).
For better ride, handling and brake cooling the Eclipse has standard 18 inch wheels. Smaller 17 inch wheels are standard on the 3 Series Coupe.
The Eclipse has a standard space-saver spare tire so you can replace a flat tire and drive to have the flat repaired or replaced. A spare tire isn’t available on the 3 Series Coupe, it requires you to depend on its run-flat tires, which limits mileage and speed before they are repaired. If a run-flat is damaged beyond repair by a road hazard your vehicle will have to be towed.
For better handling and stability, the track (width between the wheels) on the Eclipse is 2.7 inches wider in the front and 2.2 inches wider in the rear than on the 3 Series Coupe.
The Eclipse GT Coupe handles at .87 G’s, while the 335i Coupe pulls only .84 G’s of cornering force in a Motor Trend skidpad test.
As tested by Car and Driver while at idle, the interior of the Eclipse GT Coupe is quieter than the 335i Coupe (44 vs. 49 dB).
The Eclipse Coupe has .1 inches more front headroom and 1 inch more front legroom than the 3 Series Coupe.
The Eclipse Coupe has a much larger trunk than the 3 Series Coupe (15.7 vs. 11.1 cubic feet).
The Eclipse Automatic 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 driver can also remotely turn on the heater or air conditioner. The 3 Series Coupe doesn’t offer a remote starting system.
The Eclipse’s standard power windows have a locking feature to keep children from operating them. BMW does not offer a locking feature on the 3 Series Coupe’s standard power windows.