The 320's front seatbelts have an option will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The CLA-Class doesn't offer pre-crash pretensioners.
The 3 Series Sedan has standard Active Head Restraints, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the Active Head Restraints system moves the headrests forward to prevent neck and spine injuries. The CLA-Class doesn't offer a whiplash protection system.
For its top level performance in frontal, side, rear impact and roof-crush tests, the Insurance Institute for Highway Safety rates the 3 Series Sedan as a "Top Pick," a rating only granted to 170 vehicles tested by the IIHS. As of March, 2014, The CLA-Class has not been tested.
The 3 Series Sedan's corrosion warranty is 8 years and unlimited miles longer than the CLA-Class' (12/unlimited vs. 4/50,000).
BMW pays for scheduled maintenance on the 3 Series Sedan for 4 years and 50,000 miles. BMW will pay for oil and filter changes, lubrication, brake pad/rotor and fluid changes, drive belts and wiper blades. Mercedes doesn't pay scheduled maintenance for the CLA-Class.
There are over 12 percent more BMW dealers than there are Mercedes dealers, which makes it easier should you ever need service under the 320s warranty
FUEL ECONOMY and RANGE
Regenerative brakes improve the 320i Sedan's fuel efficiency by converting inertia back into energy instead of wasting it. The CLA-Class doesn't offer a regenerative braking system.
The 3 Series Sedan ActiveHybrid/diesel's standard fuel tank has 1.8 gallons more fuel capacity than the CLA-Class (15 vs. 13.2 gallons), for longer range between fill-ups. The 3 Series Sedan's standard fuel tank has 2.6 gallons more fuel capacity than the CLA-Class (15.8 vs. 13.2 gallons).
An eight-speed automatic is available on the BMW 3 Series Sedan, for better acceleration and lower engine speed on the highway. Only a seven-speed automatic is available for the CLA-Class.
INTELLICHOICE COST OF OWNERSHIP CALCULATES THE CLA250 WOULD COMMAND $1220 MORE TO OPERATE OVER 5 YEARS THAN THE 320i.