Porsche take the diesel fight to BMW with a 296bhp Panamera

It has taken a while, but finally Porsche have an engine for the Panamera which competes with BMW’s mighty 535d. The new Panamera Diesel delivers 13bhp less than the BMW at 296bhp but with 20Nm more torque at 650Nm (or 479 lb-ft).

That’s 50 bhp more than the outgoing car, resulting in a 20% increase in performance. The Panamera Diesel now accelerates from zero to 62mph in 6.0 seconds (down 0.8 secs) and 50 to 75 mph in 3.9 seconds, while its top speed increases to 161mph (up from 152mph).

The engine is all new, with a completely re-designed crankshaft and pistons. It also uses a water-cooled turbocharger for the first time, delivering increased air flow and a boost pressure of up 3 bar (an increase from 2.5 bar in the outgoing model).

The one fly in the ointment is the Panamera Diesel’s fuel efficiency. Average fuel consumption of 44.1mpg and CO2 emissions of 169g/km compares with 53.3mpg and 138g/km in the 535d. Of course the Panamera is bigger and more expensive, but nevertheless it’s the one black mark against an otherwise impressive looking powerplant.

Another plus point in the Porsche’s armoury is the new rear-axle differential lock, fitted as standard to the Panamera Diesel for the first time. Porsche Torque Vectoring Plus (PTV+) was previously reserved for petrol engine models, and as well as improving stability at higher speeds also provides a welcome boost in steering response and precision.

The system works by individually braking either the right or left rear wheel, with a welcome bonus of improving the Panamera’s ability to tow heavy trailer loads (now rated for 2600kg).

Overall though, the Panamera has been given a more sporty feel, with shorter gear ratios for the first four gears in its eight-speed Tiptronic S transmission and thicker anti-roll bars on the front and rear axle.

Unlike its competitors at BMW, Mercedes and Audi, Porsche sell just 15% of Panameras with a diesel badge. With 296bhp and 479 lb-ft now on offer, expect that figure to change when the new Panamera Diesel goes on sale in January 2014.