Tyre pyrolysis oil (TPO) can be derived from waste automobile tyres by different methods and it can be used as a fuel blended with diesel in a diesel engine. In the present work, a study was made to use Tyre pyrolysis oil derived from vacuum pyrolysis oil as a fuel in a diesel engine with the help of an ignition improver. Experiments were conducted on a single cylinder four stroke DI diesel engine using TPO as a main fuel. The performance, emission and combustion characteristics of the DI diesel engine were investigated and compared with the conventional diesel fuel (DF). Diethyl ether (DEE) was admitted along with intake air at three flow rates viz 65 g/h, 130 g/h and 170 g/h. Results indicated that the engine performs better with lower emissions when DEE was admitted at the rate of 170 g/h with TPO. It was observed that NOx emission in TPO-DEE operation reduced by 5% compared to diesel fuel operation. HC, CO and smoke emissions were higher for TPO-DEE operation by 2%, 4.5% and 38% than diesel mode. (C) 2012 Elsevier Ltd. All rights reserved.