The Lotus 81 effectively replaced the Lotus 79 as a simpler version of the failed Lotus 80. It was only intended as a stop-gap until the twin-chassis Lotus 86 was ready. But with the banning of the Lotus 86 and the Lotus 88 it had to struggle on before being replaced by the Lotus 87.
The new Essex livery...
TGP F1, Donington Park, May 2004
TGP F1, Donington Park, August 2003
TGP F1, Brands Hatch, August 2002