Normally, when you're talking about downsizing, you might be thinking of going from a 2,0-litre to a 1,4 turbocharged engine.
However, when your talking about downsizing with the full-size SUV's, it tends to go differently. The previous Q7 had a 6,0-litre V12 TDI with two turbo's as top of the range-engine,
and you can't have that nowadays. So, the new Q7 comes with a new top-diesel. A 4,0-litre V8. That might sound a little small, but in return you get three turbo's, active roll bars and a little "S" in front of it's name. Please meet the Audi SQ7, the most powerful diesel car in the world.
All of the power comes from a 4,0-litre V8 TDI, and that's quite a special engine. Why? Because it has three turbo's. Actually, that isn't really correct.
There are two exhaust-fumes turbo's. A smaller one which operates at the lower RPM's. The valvelift enables the second exhaust valve at higher RPM's, and that's when the fumes reach the bigger turbo.
That's also the point the engine reaches it's maximum output. That technology isn't anything new. However, the third turbo is special, because it actually isn't a turbo. It's an electrical compressor.
Instead of exhaust fumes, it's operated by an electrical power-unit. That comes with two advantages. First, it reacts madly quick. Within 250 milliseconds it's producing all of it's pressure, which makes the gas response very quick.
And because the compressor doesn't depend on the exhaust fumes to deliver energy, it's active at very low RPM's. The maximum torque, 900 Nm to be exact, is available at 1,000 RPM's.
and it stays that way until you reach 3,250 RPM's. When you get to 3,750 RPM's, you get the full 435 horsepower. Those horses will keep going until you hit the rev-limiter at 5,000 RPM.
But what do you notice when you drive? It pulls like an electric engine, it goes like a rocket and it sounds, especially for a diesel engine, pretty good.
It's like an American Muscle you know. A big V8 with that signature thumping. Of course, it's all show, because from the outside it's much more civilized, but from the inside it's pretty cool.
Those figures are crazy as well. I mean, 0-100 within 5 seconds...
and then all the way to it's top speed of 250 km/h. It's very impressive for a SUV which weighs 2300kg. The gas response is also pretty good if you consider it's a diesel which delivers more than 100 horsepower per litre,
Audi claims that because of the the electrical turbo, the turbo lag is gone. That isn't the case. You still experience some delay, a minimal amount, but it's still there.
But besides that, it's a very funny experience to drive this drivetrain.
That perfectly fits in with the suspension. Audi has really gone out of it's way to make this car a S-model. It's packed with technology, air-suspension, a sports-differential with torque-vectoring and active anti-roll bars.
Those use a 48-volt electrical system, you'll need that to power the electrical compressor as well. The active anti-roll bars get adjusted, dependant on the terrain you're driving and the Drive Select-system you're using.
So, if you're driving straight ahead on a bad road, it's very comfortable because the anti-roll bars are softer. But, when you engage the Dynamic Mode for example, the air-suspension and anti-roll bars get a bit more agressive.
And then it's like you're in a Tim Burton-film. Very absurdistic, but enjoyable at the same time. A minute ago it was a very comfortable SUV, but now it's a cornering machine.
Every time you think you've reached the limit, the car goes one step further. You really have to convince yourself that you can go faster than this.
So, when you're flying through a corner it's pretty crazy and fun at the same time.
But, with a Porsche Cayenne you notice it's been built to be a sporty SUV. This car however really is dependant on the fancy systems, because the car itself still feels quite heavy, especially when braking. You feel it pushing through.
Another little thing is the steering, typical Audi-like. It's pretty senseless. That isn't really a big issue, but the power-steering is not consistent,
One moment you'll have to pull very hard, and the other it steers very smoothly. That inconsistency isn't very nice to handle.
Another disadvantage is that this car is dependant on it's systems. And it's an Audi, so a lot of the systems are options. The air-suspension and electrical compressor are standard, but the active anti-roll bars are, just like the sporty differential
and carbon ceramic brakes. So, there are a lot of things you'll need to push this car to it's limits. And that means spending money. It might not be a V12 TDI anymore, but 189 grams of CO2 per kilometre means a lot of BPM,
it means a starting price of just below €121.000, and then you'll still have add the options. I don't thing you're going to see this SQ7 very often.
As technical masterpiece it sure is impressive. An electrical compressor is a fine piece of engineering, so if that technology were to be used in 'normal' cars, this might become a big thing.