The Lexus GS will get a four-cylinder hybrid model in the near future, according to senior company sources.
Currently, the BMW 5 Series rival has a 286bhp V6 petrol-electric hybrid powertrain that averages 46.3mpg and emits 141g/km of CO2.
Its likely the new GS model will be powered by the 217bhp 2.5-litre four-cylinder petrol-electric hybrid powertrain that's used in the new IS300h, where it has emissions of 99g/km and average economy of 65.7mpg.
Fitted to the bigger GS, it should make the Lexus competitive with the BMW 520d Efficient Dynamics, which returns 119g/km and 62.8mpg.
Sources also admitted that the new Lexus IS 'does need a cheaper entry-level model'. Currently the IS range starts at 26,495 for a 2.5-litre V6 petrol model, while the 29,495 hybrid IS300h is priced slightly above its direct rival the less powerful, 109g/km BMW 320d.
Its possible that a new entry-level Lexus IS will have a non-hybrid petrol motor that will fall short of efficiency and performance offered by the IS300h, but will provide an affordable way into the range.