Well, this is unusual. For the first time that we can remember, the desire to boost environmental credentials by Lexus has come at the expense of power and performance for the IS, and you have no choice in the matter.
The IS200d, which replaces the IS220d, retains the same 2.2-litre, four-cylinder diesel engine but with changes to its combustion chamber and piezo-electric fuel injectors. It also now has a diesel particulate filter to meet Euro 5 emissions standards. The result is a claimed combined economy figure of 55.4mpg (up from 50.4mpg) and a CO2 figure of 134g/km (down from 148g/km). However, power and torque have also been reduced. The IS200d's 148bhp and 251lb ft are 27bhp and 44lb ft down on the model it replaces.
In urban use, this isn't so much of a problem, because the spread of torque is sufficient for smooth progress. But out of town, the IS200d needs to be worked for its performance and, even then, it is slower than some rivals.
The mainstream petrol choice is a 2.5-litre V6. Despite the impressive capacity and number of cylinders, it produces just 205bhp and a feeble 186lb ft of torque, and then only at 4800rpm. Try anything more pressing than wafting and it really isn’t interested. Switching to Sport mode does improve the situation, but only slightly.