Mercedes-AMG originally intended for the E 63 and E 63 S models to produce no more than 571 PS and 612 PS respectively. Yet, German tuner RENNtech had other plans.

Opting for the R800 performance package means increasing output to an impressive 800 PS at 6,800 rpm. Maximum torque is then limited at 1,050 Nm (774 lb-ft), considerably more than the 750 Nm (553 lb-ft) and 850 Nm (627 lb-ft) generated by the E 63 and E 63 S when stock.

Customers can also get the optional ceramic-coated downpipes with 200-cell sports cats, which add an extra 20 PS while further-boosting the soundtrack in Sport and Sport+ modes. Meanwhile, the noise levels in Comfort mode remain relatively the same as before, in both the E 63 and E 63 S.

As far as pricing goes, the R800 performance package will set you back close to €15,000 ($17,519) if you also go for the Vmax increase, TUV approval and engine and powertrain warranty (up to 3 years, 100,000 km / 62,000 miles), or just under €12,000 ($14,000) if you skip those steps.

In a straight line, the RENNtech E 63 S can cover a 1/4 mile in just 10.43 seconds, at 214 km/h (133 mph). That’s a personal best for any W213 E-Class, and an improvement over last year’s record time of 10.68 seconds posted by a 773 PS Mercedes-AMG E63 S at the Palm Beach International Raceway. However, that car only featured an ECU upgrade, whereas the R800-equipped one also came with a BMC air filter, BOV adapters, the previously-mentioned downpipes with 200-cell cats, a fuel system upgrade and upgraded turbo tech.