The fact that Subaru has been able to announce the arrival of an automatic diesel Outback is news indeed. But there's much more to this than a single car with a new transmission.

It has been well-known that people in New Zealand spending more than $45,000 on a car don't really want to change their own gear ratios. This meant that the turbodiesel versions of recent Outback, Legacy and Forester models didn't sell as well as perhaps they could, because they were not available with an automatic transmission.

Subaru is to introduce its first automatic transmission diesel in the Outback early next year, and from that we can read a few other things. Firstly, it means that similarly equipped diesel Legacy, Forester and Impreza models will probably follow. Secondly, the fact that the new transmission is a CVT unit, like those fitted to Subaru's petrol fours means that as it has been created for the high torque output turbodiesel flat fours, this new generation Subaru Lineartronic Transmission (SLT) will also be capable of handling the company's more powerful petrol engines, like the turbocharged fours and of course the 3.6-litre flat six engine used in the Tribeca SUV and some Legacy models. These currently use conventional five-speed automatic units rather than CVTs.

Coupling CVTs with diesel is a brilliant blend, and I've driven Ford and Audi products with just such a set-up, with the pulley and belt unit able to match the engine's torque peak with speed and gearing much more accurately than a conventional automatic with all its inherent slippage. This not only adds up to seriously high levels of refinement, but also some excellent economy figures, something we all have to think about these days.

This will be the first time Subaru has offered an automatic diesel in New Zealand and the company's managing director for New Zealand, Wallis Dumper, says: "Our diesel Outback has been the most economical diesel 4WD at the last two Energywise economy rallies, but we also know the diesel market is dominated by automatic transmission models, so the addition of the diesel automatic Outback for Model Year 2013 is significant news for Subaru.

"We know there's massive pent-up demand for auto diesels, particularly in rural and regional areas, so its a great opportunity for us to meet the needs of those customers," said Dumper.

"The Lineartronic transmissions in our petrol cars are a huge hit, typified by the new XV and Impreza, so we can only see good things for Outback auto diesel."

It also has to be noted that the growth of diesel take-up in the non-truck area in the United States has taken off, and already Volkswagen, Mercedes-Benz and BMW are taking advantage of the trend, which is easily outstripping the growth in hybrid and plug-in electric car sales in the US, despite there being no subsidy for diesels. GM is looking at diesel Cruze models for the US, while Honda is developing a V6 diesel, and Nissan/Infiniti is investigating the use of its Renault-derived joint venture diesels for various models.

With the US having a predominantly automatic-leaning populace, like our market, the addition of diesel with CVT automatic is very sensible.

Minor RHD markets like New Zealand and Australia could suffer if Subaru's automatic diesels take- off in Britain, where historically the brand has had a very large take-up among the gentleman farming sets, because at one time Subarus were only available from farming outlet stores.

That segment has always been attracted to automatics and diesels, and with Subaru offering them a new no-brainer decision, Down-Under markets might just starve a little with supply.

Let's hope not - these Subaru diesels have already been judged among the best four-cylinder units in the business.

- © Fairfax NZ News