With the extraordinary C111, Mercedes set a string of diesel world speed records. The original C111 had a record low drag of 0.18 cf and used a Wankel rotary engine to propel it to 180mph. This was itself eclipsed by three future versions using turbo-diesel engines of up to 500bhp. In 1979, The twin turbo V8 Mk IV achieved an astonishing average top speed of over 250mph.