In my recent article “Record Diesel Prices – Will Car Drivers Move Back to Petrol“, I suggested that the current vogue for diesel cars of all sizes might be nearing an end. The premium price diesel vehicles command when new and the increased price gap between petrol and diesel mean that drivers need to do quite high mileages before diesels (with their better fuel economy) pay for themselves.

Just a couple of days later, I noticed this news release from Mercedes-Benz announcing that by 2010, all of its engines will be turbo-charged. It doesn’t specifically mention petrol engines, but since all Mercedes’ new diesel engines are already turbo-charged, this must be a reference to its petrol engines, many of which are still rather large and not turbo-charged.

Although most obviously of relevance to luxury car drivers, this is an interesting indicator of the way the market looks likely to go. I can easily see the same technology being applied to small, low-payload vans. Smaller, turbo-charged petrol engines – of the kind Saab have been using for years – offer comparable performance to larger, normally-aspirated engines and have lower emission ratings.

Reducing CO2 emissions, of course, is the primary motivator for Mercedes’ decision. Ever-tightening EU emissions rules mean that regular reductions will be required for manufacturers to escape fines in the years to come.

I look forward to seeing how different manufacturers meet this challenge.