Yes it is, but the N53 is not in your car. I was talking about you having the latest N52 (which you have) is better than the original.
IF you had the N53 engine - economy would be better again.
Compared with its N52 predecessor which was port-injected, the N53 uses direct injection (consisting of Piëzo-electric injectors directly in the cylinder) with a stratified lean mixture operation.
The N53 has variable valve timing (called double vanos by BMW). Unlike the N52, the N53 does not contain variable valve lift (called valvetronic by BMW) due to space limitations in the cylinder head.
..sweet torquin' diesel!