Adding new technology has reduced rather than increased the price of some Mercedes-Benz C-Class models - by up to $2300.

Four-cylinder petrol sedans and wagons now have stop-start engine technology, returning 7.0L/100km.

This eliminates exposure to the luxury car tax, which applies to cars that use 7.0L/100km or more, cutting in at $57,466.

The fuel use on the C-Class four-cylinder petrol sedans drops from 7.2L/100km to 6.8L/100km, slicing pricing of the C200 by $300 to $58,600 and the C250 by $2300 to $65,600.

Among wagon models, the C200 is now $60,600 and the C250 $67,600.