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Cast of new six-pot engines for BMW

POSTED BY Nigel Andretti ON 18 May 2016

GERMAN premium automaker BMW has announced new petrol and diesel engine technology will be on the road soon.

BMW said its refreshed M135i and M235i models will be renamed the M140i (main pic) and M2401 once they get the more powerful six-cylinder turbocharged petrol engines under their bonnets.

The new in-line six cylinder 3.0-litre unit develops 336hp at 5500rpm and 500Nm from 1500-4500rpm, representing a 13hp/50Nm increase over the outgoing versions.

The new engines will start rolling off the production lines in Europe in July.

The M140i and M240i – part of BMW’s M Performance stable – feature further developed TwinPower Turbo technology and use an eight-speed Steptronic Sport dual-clutch automatic transmission, although manual fans can order a six-speed gearbox as a no-cost option.

BMW says it has improved the gearbox, which now features a throttle blipping function on down-shifts, while the auto has also been enhanced for greater fuel efficiency.

Performance and fuel economy gets a lift with the M140i completing the 0-100km/h dash in 4.6 seconds when matched with the auto, a 0.3s improvement over the M135i hatch. The manual is 0.2s slower.

The M240i Coupe’s 0-100km/h has dropped by 0.4s to 4.6s for the auto (4.8s for the manual), while the drop-top is 0.3s quicker at 4.7s (4.9 in manual guise).

The all-wheel drive xDrive versions are even quicke.

Fuel use has also improved, with auto versions of the M140i down from 7.5 litres per 100km to 7.1L/100km (7.8L down from 8.0L in the manual), while the M240i is also down from 7.6L to 7.1L for the auto Coupe (7.8L for the manual) and the Convertible has dropped from 7.9L to 7.8L (8.3L for the manual).

BMW says the new engine features an aluminium crankcase and cylinder head, and that refinement has been further improved by the use of new near-source acoustic shielding. Electric wastegate control and the close-coupled arrangement of the catalytic converter help to lower emissions, according to the car-maker.

Responsiveness and efficiency is improved thanks to the latest version of the Valvetronic fully variable valve control and the M Performance models also get Double-Vanos variable camshaft timing on both the intake and exhaust sides.

The all new quad-turbo, six-cylinder diesel (below), will be used by the 750d xDrive and BMW 750Ld xDrive, BMW said.

The new diesel generates maximum output of 400 hp and peak torque of 760 Nm.

bmwdiesel

The 19 hp (5%) increase in output and peak torque up by 20 N·m are accompanied by a 11% reduction in average fuel consumption and emissions over the predecessor model. Combined cycle fuel consumption is 5.9 – 5.7 l/100 km (39.8 – 41.2 mpg US); the corresponding CO2 emissions are 154 – 149 g/km. The engine comes standard with intelligent all-wheel drive.

The new unit’s BMW TwinPower Turbo technology includes multi-stage turbocharging with four turbochargers and common-rail direct injection, the latest update of which generates maximum pressure in excess of 2,500 bar.

The new BMW 750d xDrive accelerates from 0 to 100 km/h in 4.6 seconds (BMW 750Ld xDrive: 4.7 seconds)—an improvement of 0.3 seconds over its predecessor.

Much credit for this even sharper dynamic edge can go to a new form of multi-stage turbocharging, which now brings together four turbochargers in place of the previous three. This enables boost pressure to be built up even more quickly at lower engine speeds and therefore prompts incredibly swift responses to throttle applications from idle.

The engine develops its maximum output of 400 hp at 4,400 rpm. Its optimised performance characteristics are reflected most prominently in torque development that gathers pace rapidly and from low engine speeds.

The engine delivers more than 450 N·m of torque at just 1,000 rpm and puts its maximum 760 N·m on tap between 2,000 and 3,000 rpm.

The engine’s eight-speed Steptronic transmission has been tuned to ensure that instant and ferocious bursts of pace can also be achieved under throttle inputs at higher speeds. The BMW 750d xDrive and BMW 750Ld xDrive have an electronically limited top speed of 250 km/h (155 mph).

The effectiveness and performance characteristics of the new engine are determined largely by the first use of a fourth turbocharger and—above all—the precisely coordinated interplay of all the components in the turbocharging system. As with the outgoing engine, the performance-boosting flow of compressed air into the combustion chambers is generated by multi-stage turbocharging.

The high-pressure stage revolves around two compact turbos with variable turbine geometry integrated into a single housing, while a single, very large low-pressure turbocharger has been replaced by two smaller—and therefore faster-responding—units.

The two low-pressure turbochargers and one of the two high-pressure turbos are permanently in action. Only under hard acceleration from idle will the two low-pressure turbochargers be bypassed by means of a flap control system.

This allows boost pressure to be built up even more quickly. The second high-pressure turbocharger is brought into play at an engine speed of about 2,500 rpm.

To enhance efficiency, the engine also employs an indirect system of charge air cooling with higher capacity than that used by the outgoing engine, as well as additional compressor backplate cooling for the low-pressure turbochargers.