The CLE’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The MX-5 Miata doesn’t offer pre-crash pretensioners.
In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the CLE are reminded to check the back seat. The MX-5 Miata doesn’t offer a back seat reminder.
The Mercedes CLE has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags help prevent the driver and front passenger from sliding under their seatbelts or the main frontal airbags; this keeps them better positioned during a collision for maximum protection. Knee airbags also help keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The MX-5 Miata doesn’t offer knee airbags.
The CLE has a standard front seat center airbag, which deploys between the driver and front passenger, protecting them from injuries caused by striking each other in serious side impacts. The MX-5 Miata doesn’t offer front seat center airbags.
Over 200 people are killed each year when backed over by motor vehicles. The CLE has standard Maneuvering Assistance that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The MX-5 Miata doesn’t offer backup collision prevention brakes.
The CLE has all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The MX-5 Miata doesn’t offer all-wheel drive.
Earlier warning of stopped traffic, traffic signals, dangerous road conditions, weather, or accidents, can keep driver's safer and prevent crashes. The CLE has Car-to-X Communication, a system that seamlessly communicates important warnings to the driver about impending danger, if they're available. The MX-5 Miata doesn’t offer a system that can receive automated systems from infrastructure or other vehicles.
The CLE offers an optional Surround View System to allow the driver to see objects all around the vehicle on a screen. The MX-5 Miata only offers a rear monitor.
Both the CLE and MX-5 Miata have rear cross-traffic warning, but the CLE has Active Brake Assist (automatically applies the brakes) to better prevent a collision when backing near traffic. The MX-5 Miata’s Rear Cross Traffic Alert doesn’t automatically brake.
The CLE’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The MX-5 Miata doesn’t offer a driver alert monitor.
Both the CLE and the MX-5 Miata have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, blind spot warning systems, rearview cameras, rear cross-path warning and available lane departure warning systems.
The Mercedes CLE weighs 1542 to 2120 pounds more than the Mazda MX-5 Miata. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts. Crosswinds also affect lighter cars more.

