The S550 is powered by a completely new engine, the 5.5-liter V8 that has gone back to a 4-valve-per-cylinder design. It offers extremely high levels of standard equipment, befitting its high market position. Virtually every comfort and convenience item is standard, with a huge option list to ease customization. The V8 engine comes mated to a seven-speed automatic. The new S-Class safety package is unequalled in the class, with all the usual brake and airbag technology upgraded and Pre-Safe accident-readiness equipment made standard. The Electronic Stability Program is back as standard equipment, with two new features: trailer stabilization, and tire-pressure monitoring.The Mercedes-Benz S-Class is fully re-designed for 2007.