







MORE AT CARS.COM

This story originally appeared on Yahoo Autos in June 2013, and was one of the most popular pieces we ran this year.

The 2014 Jeep Grand Cherokee SRT8 is home to perhaps one of the most appropriate buttons we've encountered in the What Does This Button Do? series. Mysterious buttons are rarely spelled out as clearly as the Jeep SRT8's, or as fun to use.

By spelled out, we mean the whole word, "Launch," appears on the button to designate the 470-horsepower, all-wheel-drive Jeep SRT8's Launch Mode. There are no acronyms or guessing with this button. What the button does is also made clearer by the awesome depiction of a drag strip's starting-line lights, aka a "Christmas tree."



[Related: Jeep Grand Cherokee SRT8, a ‘shine runner’s dream: Motoramic TV]



Jeep's launch control is standard on SRT8s for consistent, enhanced fast starts of the high-performance SUV. Launch Mode brings the engine, suspension, transmission and driveline together for fast launches from a standstill by revving the engine at a standstill and launching the 5,000-pound SUV like a rocket.





To activate, Jeep's instructions say the SUV must be stopped on a level surface before fully depressing the brake pedal - while in Drive - and then pressing the Launch button. While holding the brake, mash the accelerator pedal to the floor within a half-second and the engine will rev to a predetermined rpm. Once the engine speed is up, all the driver has to do is lift the brake and the SRT8 launches perfectly every time.



Cars.com reviewer Aaron Bragman tested the SRT8's Launch Mode at the vehicle's introduction:



"Jeep rates the SRT Grand Cherokee at 4.8 seconds from zero to 60 mph, but I discovered that this is a conservative figure: Using the SRT's onboard software and a special launch button, I was able to consistently rip off 4.5-second zero-to-60 times, and SRT engineers say that they've been able to achieve 60 mph in 4.2 seconds under perfect conditions."



