12 Mar 2013

Audi introduces cylinder shutdown to the A1 and A3

Audi introduces the new fuel efficient CoD engine across the A1 and A3 range.  CoD stands for Cylinder on Demand

No, it isn't Call of Duty, Audi style.  CoD stands for Cylinder on Demand and is an eminently sensible technology that has been available on high end cars, such as the Audi S6, for some time and that has, thankfully, filtered down to lesser models.  It is also something we highlighted as being a technology that really should be available on all road cars just one week ago.

The idea is simple.  When not actively accelerating two of the four cylinders are deactivated by means of sleeves placed in the cam area.  The sleeves come into action when acceleration isn't called for and provide zero lift for the cams - thereby preventing injection and combustion in those cylinders.  The sleeves rotate to provide normal lift when acceleration is required.  This happens in 13 to 35 milliseconds depending on engine speed.

The ultimate result is that less fuel is used and petrol engines start to produce mpg and CO2 results closer to their diesel siblings.  The 140PS 1.4TFSI models can now produce almost identical mpg and CO2 (and therefore tax benefits) as the equivalent 2.0TDI models.

The 140PS 1.4TFSI CoD engine in the A1 can do the 0-62mph run in 7.9 seconds and return 60.1mpg and 109g/km of CO2.

The same engine in the A3 also returns 60.1mpg and 109g/km of CO2 and does 0-62mph in 8.3 seconds.  All these figures are achieved with a 7 speed semi-automatic in the A1 and a 6 speed manual gearbox in the A3.

Prices for models with the CoD engine are slightly higher than their non-Cylinder on Demand counterparts so, for example, the A1 Sport with S tronic gearbox costs £18,190 and the A3 Sport with manual gearbox costs £20,055.

The great thing about CoD technology is that it should allow more company car drivers to buy petrol engined cars, which in turn means we get to hear less dreary diesel engines on our roads.  It's a win win situation.