The US ‘Big Three’ car makers are getting a serious kicking at the moment. Much of the criticism is centred on failing to build cars that matched the - mostly Asian - competition.

That, of course, and their notorious reliance on ‘gas-guzzlers’.

However, Ford has just let the press drive its new US-market Fusion Hybrid and the narrative could be about to change.

The Mondeo-sized Fusion (which is actually based on the Mazda 6) gets a mild hybrid set-up, with an electric motor/generator sandwiched into a CVT transmission, which is driven by a 2.5-litre four-cylinder petrol engine.

It's an updated version of the hybrid transmission in the Ford Escape SUV. The nickel-metal-hydride battery pack now weighs 70kg(23 percent less) and other changes will now allow the Fusion to hit 47mph in pure electric mode.

Amazingly, the first results from test drives in LA suggest the Fusion is capable of around 50mpg in UK gallons.

If this is replicated in real life use, switched-on European drivers will be wondering when an ‘Electric Mondeo’ will appear.

That’s because it’s not just about the fuel economy argument. One of the main reasons Toyota developed the hybrid is because it delivered better fuel economy without the tailpipe pollution of a diesel.

In fact, the previous-generation Escape Hybrid met Super Ultra Low Emission Vehicle (SULEV II) and Advanced Technology Partial Zero Emissions Vehicle (AT-PZEV) standards.

Indeed, so strict are Californian’s air pollution standards, diesel-powered cars were effectively banned in 1990 because of their particulate (soot) and nitrogen oxide (NoX) emissions.

Today, diesel cars can only be sold in California if they meet standards so strict that they’re equivalent to Euro 6 limits,  which are not due for introduction in Europe until 2014.

This is relevant to us Europeans, because there evidence that the EU will be following California’s lead and clamping down even further on the particulates and NoX emissions, particularly in city centres.

And while diesel engines can be cleaned up with complex NoX traps and urea injections, will it be easier – and cheaper – in the long run to switch to a Fusion-style petrol-hybrid drive train?

Will the electric Mondeo remain a dream, or could it kill the diesel?