BMW have announced they will be releasing thier most powerful diesel engine setup next year. Most cars are happy with 1 turbo, some use 2, a few have 3 turbos, but BMW decided 4 should be fun! No official statistics yet, but it's expected to get over 400 hp with monstrous amount of torque, probably enough to tow a small planet. Wonder if having quad turbos brings any economy benefits?
I think a big benefit of 4 turbos is that they'll lighten your wallet nicely
There are lots of people with the "more is better" mindset. Think Spinal Tap with their guitar amps that go to "11". Got 500 hp? Weenie! I can kick your butt 'cuz I have 600! Only two turbos? That's so yesteryear. I have 4! There was even a sports bike that sold a few years ago whose biggest selling point was its unusually high RPM! Yes, I'm serious. Imagine bragging that your bike's engine spins faster than the other guy's.
Truth be told, few people can take an average sedan to its limits on a track. But that doesn't sell bigger numbers to those for whom bigger numbers are important.
This is true to some extent, but ultimately I think the real reasons are probably emissions related, as Euro emissions standards tighten, car manufacturers want to reduce emissions and fuel consumption, but not loose any performance. You may notice cars getting smaller and smaller in the engine department, yet HP figures getting larger and larger. It's like manufacturers want to comply, but thier way of keeping the market alive is to make the engines as powerful as possible.
Draigflag: Your car seems to be getting great fuel economy without quad turbos. My 2015 Audi Q5 3.0 diesel gets 6.9 L/100km = 34.17 US MPG = 41 UK MPG, with 240 hp and 428 ft-lbs torque, 0-60mph in 6.7 sec, and it has only 1 turbocharger... and as a non-racer, I can't complain about turbo-lag.
As far as I can see, people have produced great engines without needing to resort to 4 turbochargers, just like they've created a lot of great guitar amps without needing the volume knob to go to "11" :-)
You make a good point, more power is not something we need, but for some, it's something they want, and so long as fuel consumption or reliability is not comprised along the way, there's no harm in having tuned up versions of every car, the more choice the better.
I used to have a Classic Fiat 126 with just 26 bhp, it was enough to keep up with traffic and down hill would do 72 mph! I too started asking if I needed any more power! Cars are getting lighter and lighter these days, as long as people use the power/weight ratio, there's no need for big engines anymore unless you need to tow things.