Power figures remain unchanged at 108kW/110kW (Forester/Outback) and 350Nm of torque, but maximum twist now comes online between 1600 and 2400rpm, compared to 1800-2400rpm for the 2011 model.
Combined-cycle fuel consumption has also improved, dropping from 6.4 l/100km for both cars in 2011, to 6.0 l/100km in the 2012 model year.
The improvements come courtesy of changes to the diesel engine and to the six-speed manual transmission.
In the case of the engine, Subaru has tweaked the turbocharger and EGR cooling, along with the exhaust-cam timing, coolant circuit and vacuum pump efficiency.
There is also a larger coolant pump pulley, lighter connecting rods and new journal knock pins on the cylinder block.
The transmission gets a shorter stroke for 2012, along with low friction bearings, a baffle plate in the differential chamber, changes to the spline module, optimised diagonal gear changing, improved lubrication channels and a new over-revving warning system.
"These significant refinements to engine and transmission make an even more compelling case," Subaru Australia Managing Director Nick Senior said.
"The smoother gear change helps more efficient driving and better fuel economy, which is a major focus for Subaru diesel customers."
As for an automatic transmission to go with its diesel engine, Subaru Australia has confirmed that while an auto is on the company's wishlist, a timeline has yet to be confirmed by Subaru's Japanese headquarters.
- Forester 2.0D manual - $36,490
- Forester 2.0D Premium manual - $40,990
- Outback 2.0D manual - $40,990
- Outback 2.0D Premium manual - $46,990