The Lexus LS has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags helps 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 CLS doesn’t offer a front passenger side knee airbag.
The LS has standard Secondary Collision Brake, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The CLS doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.
Over 200 people are killed each year when backed over by motor vehicles. The LS has a standard Parking Support Brake that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The CLS doesn’t offer automatic braking for stationary objects directly to the rear.
The LS’ standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. A lane departure warning system costs extra on the CLS.
To help make backing out of a parking space safer, the LS has standard Rear Cross-Traffic Alert and Parking Support Brake automatically engages the brakes to help avoid a collision. Mercedes charges extra for Rear Cross-Traffic Alert on the CLS.
Both the LS and the CLS have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front and rear seatbelt pretensioners, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, blind spot warning systems, rearview cameras, driver alert monitors, available all wheel drive and around view monitors.
The Lexus LS weighs 441 to 838 pounds more than the Mercedes CLS. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.