Why the Audi RS3 Concept Is A Big Deal

Yesterday VW revealed the A3 Clubsport Quattro – which is believed to be a concept prototype of the upcoming RS3 sedan.

The biggest news comes from the concept car is its 525hp 5-cylinder turbo engine. From my point of view, this is a revolution in the market. The reason is: VW is able to pump out 525hp from the 2.5-litre displacement, using only 1.5 bar pressure of turbo boost, this translates to 212hp per litre. For comparison, the Mercedes-Benz M133 engine which is used on the CLA45AMG, is using a much higher 1.8 bar of boost, but can only achieve 181hp per litre.

The VW engine has excellent torque curve too: 443 lb-ft available from 2300 to 6000 rpm. This engine is using an air-to-air intercooler, which is different from the Mercedes M133 (using a water-to-air intercooler). One thing we are not sure at this moment is: how is the turbo lag of this engine. For the Mercede M133 in the CLA45 AMG, the turbo lag is obvious, which can be proved by the big difference between the 0-60 and 5-60 rolling start time.

Some media claimed this VW engine is EA113, that is completely wrong. The engine on this RS3 concept  is using a CGI (Compacted Graphite Iron) cylinder block, and it is the only petrol engine in the world currently that uses such material in its construction. Because of the CGI material’s extra strength, the engine has great potential for turbocharging, this is an absolute advantage that the aluminum cylinder block turbo engine that cannot match.

It is estimated that the production version of the RS3’s output will be detuned to around 400hp, and maybe it will not use this 5-cylinder turbo engine seen in the A3 Clubsport Quattro concept (and instead use the I4 engine in the VW R400 concpet); but at the 400hp-level, this still sets a high bar for Audi’s competitors such as the CLA45AMG and the future BMW M2.

Note: by saying “1.5 bar of boost”, it means the total air pressure in the turbocharger is 1 + 1.5 = 2.5 bar, which is atmospheric pressure (1 bar) + extra pressure generated by the turbocharger (1.5 bar).