It was just a matter of time before BMW took the thinking that went into the N54/N55 direct injected turbocharged six cylinders and applied it to the naturally aspirated N52 six. And the result is a direct injected two liter turbocharged four cylinder that will roll out in the North American market in the X1 and, before long, probably all other vehicles that use that currently the N52B30 six.
Odd thing is, if you look at the rated HP/Tq numbers for the N52 they vary by installation. The 128i/328i show max HP as 230 and torque at 200 lb ft (at 2750 RPM). The new ‘X3 xDrive 28i’ (can they make the naming
any more ridiculous?) is 240 max HP and 221 lb ft (at 2750-4000 RPM). The 528i is 240 max HP and 230 lb ft (at 2600 – 3000 rpm). So, it would appear that the engineers are optimizing torque for the platform the
engine is used in.
BMW N52 6-cyl shown here
What we know about the turbo direct injection motors is that they start with bags of torque off idle (~ 1300 RPM) and the torque curve stays flat to at least 4000+ RPM. Stump pulling amounts of torque. The new four compares quite favorably with an NA six for power output.
For instance the Mercedes Benz C300 Sport uses a 3 liter V6 that produces 228 HP and 221 lb ft of torque from 2700 to 5000 RPM. That’s decent power. Lose a liter gain a turbo and you get slightly better HP and significantly better torque right off the line (1250 RPM) with the new BMW engine.
So it’ll be a decent substitute for the N52 from a power production standpoint. Because it’s shorter, it may also contribute to even better handling dynamics. And since it’s a turbo, there will be after market mods galore for it and within five months of it appearing in the US market some tuner will be bragging about hitting 325 HP with the thing.
Any downside? Yeah, just a bit – the N52 seems to be the swan song of the naturally aspirated inline six (even Volvo may walk away from their NA inline six if rumors are correct). And in the grand scheme of things,
while the new engine will be more powerful and more frugal, it’ll still bring a wisp of sadness when the N52 is no more . . .