The recent Geneva Motorshow was packed with a lot of new releases so much so that it’s impossible to cover each one with any degree of detail. Detail to many readers is tedious and full of corporate facts. But we can at least distill one or two releases of interest. Take the Audi SQ7, it features the first electric diesel supercharger.
So what makes Audi’s SQ7 different from the traditional clan of turbochargers. Think of the SQ7’s supercharger as an air compressor that increases the density of air supplied to an internal combustion engine. In layman’s terms, the more air the more power.
The supercharger is usually belt or chain driven. This is in contrast to a turbocharger which uses the waste exhaust gas of an engine to power a turbine which provides more power and therefore more fun.
But turbocharged engines typically suffer from turbo-lag which is caused by those exhaust waste gases taking time to spool up the turbines.
Superchargers benefit the driving experience by offering a good low rpm boost but because they are belt driven i.e. powered by the engine they do suffer from a slight loss of bhp.
The Audi SQ7 will see the debut of a 4.0-litre V8 diesel that is fitted with two turbochargers and an electric supercharger/compressor. Audi say it will be the most powerful diesel engine of its type.
And for once Audi might be right with 435bhp and 900 Nm of torque from as low as 1,000rpm and 3,250rpm the SQ7 can romp from 0-62mph in 4.8 seconds and is limited to a top speed of 155mph.
Audi claims the SQ7 can return 38mpg and has a CO2 footprint of 194g/km. In essence, the electric supercharger is designed to assist the SQ7’s traditional twin-turbochargers.
This ‘assist’ eliminates turbo lag and because the electric supercharger/electric compressor isn’t belt driven that means no loss of power associated with a traditional chain-driven supercharger.
To power the electric supercharger (compressor) Audi has installed an additional power supply which comes in the form of a 48v lithium-ion battery which is located underneath the boot floor.
The flagship SQ7 also receives a few minor external and interior design updates and will arrive in UK showrooms by August costing an eye-watering £70k.