As the name suggests, the 308 GT THP 175 uses the same 1.6 litre 175bhp petrol engine as the 207 GTI THP 175.
Developed with BMW, this unit features an overboost facility which boosts torque from 180lb/ft to 195lb/ft.
As a result, on-paper performance is similar to the 2.0 307 Feline 180, with the sprint to 62mph taking 8.3 seconds and a top speed of 140mph.
However, it’s more economical than its predecessor.
Fuel economy is up from 33.6 to 37.1mpg, and emissions have fallen from 200g/km to 180g/km, meaning a £40 saving on road tax compared to the 307.
To go with the performance boost, the 308 has gained a deeper front bumper and rear spoiler, and sits closer to the road than the rest of the range.
This is continued inside with an aluminium gear knob, foot pedals and a new steering wheel.
The 308 SW offers a more spacious alternative, with a 100mm longer wheel base and 124mm extra overhang compared to the hatch.
This extra space means the SW can accommodate an extra row of seats, or up to 2,149 litres of load.
Like the 307 SW it also features a panoramic glass roof, which now extends beyond the second row of seats, and the rear hatch glass can now be opened independently.
Buyers can choose from a range of petrol and diesel engines, including the 175bhp turbocharged unit from the 308 GT hatch.
The GT THP 175 will go on sale in April, with the SW following in June. Pricing and full specification will be released closer to the launch date.