BMW is extending the 1 Series line-up in the UK with a new model consisting of a brace of high performance twin-turbocharged engines and a diesel capable of a frugal 58.9mpg.

The new BMW 1 Series Coupe goes on sale in November and will be available in 120d, 123d and 135i guises.

The 135i marks the first time a twin-turbo petrol engine has powered a 1 Series, while the launch of the 123d heralds the introduction of the world's most powerful production four-cylinder diesel engine.

The flagship of the range is the BMW 135i with its 3.0 litre twin-turbocharged petrol powerplant. Offering 306hp from its light alloy and magnesium straight-six engine, the 135i is capable of accelerating from zero to 62mph in 5.3 seconds before going on to an electronically-limited top speed of 155mph.

Peak torque of 400Nm from just 1,300rpm through to 5,000rpm ensures smooth yet rapid progress and in-gear flexibility.

The 2,979cc engine posts a 30.7mpg figure on the combined cycle and a CO2 emissions figure of 220g/km.

The BMW 135i is joined in the range by another twin-turbocharged model to offer a unique blend of performance and economical motoring. The 204hp four-cylinder engine in the BMW 123d Coupe sets a benchmark for small diesels.

Its 1,995cc powerplant is the world's first all aluminium diesel to have an output per litre figure in excess of 100hp - something only BMW M cars usually attain. It is also the first four-cylinder production diesel to come with twin-turbo technology.

Peak torque is 400Nm from 2,000rpm, while the engine revs to in excess of 4,400rpm where peak power is attained. This performance equates to a zero to 62mph time of 7.0 seconds and a top speed of 148mph - previously unheard of figures in such small capacity production diesels.

By comparison the output of the four-cylinder BMW 123d betters that of established six-cylinder diesel engines from both Audi and Mercedes.

The BMW 123d Coupe also makes financial sense. Its 138g/km emissions figure sees it fall into the Band C Vehicle Excise Duty tier while the fuel consumption figure on the combined cycle is 54.3mpg.

It is aided in this by the use of elements from BMW's renowned EfficientDynamics programme. The 123d comes with Auto Start-Stop technology, brake energy regeneration, third-generation common-rail fuel injection, a diesel particulate filter, active aerodynamics, electric power steering and low rolling resistance tyres.

For customers seeking an entry point into the new 1 Series Coupe range, the 120d offers another option of style, driving dynamics and parsimonious motoring. Its 1,995cc four-cylinder engine mixes a 177hp output and a zero to 62mph time of 7.6 seconds with 58.9mpg economy and emissions of just 128g/km.

Prices for all three models will be announced closer to the on sale date.