gsobol

There are so many differences between supercharged and turbo charged engines. It really all depends what you are going for. Considering that both types are much more expensive to produce than naturally aspirated engines, the only reasons why we have them available in such an abundance now is fuel efficiency. When choosing between the two, manufacturers usually tend to go with turbo rather than a supercharger. Turbo charged engines have more packaging options, and are easier to tune to specific applications. They also appear to be marginally more fuel efficient than supercharged ones. However, supercharged engines deliver torque and horsepower much quicker making them comparable and an ideal choice as a replacement for naturally aspirated V8. The Audi 3.0 TFSI has such a flat curve, it's amazing that you really almost can't tell when it goes through it's RPM gauge and when it upshifts it's still pulling the same way. Forgetting turbo lag, turbo and naturally aspirated engines have a much steeper power curves with a much more pronounced power increase usually around 3K RPM.

Chances are that Audi will eventually go with turbo engine. Chances also are that it may be a slightly larger 4 banger than the ubiquitous 2.0T that's in the car now. It's all about the money at the end. VW group has other brands to put larger (more expensive) engines in, such as Porsche and Bentley. I would personally be sorry to see such a great engine go (unless we could get the Tri-Turbo 4.0 V8 diesel - fat chance at that ....)

Jim Jistel

BigKutta curious why you're not a turbo fan. The new generation twin scroll turbos have almost instant response. I'd be hard pressed to tell the difference vs a supercharger. And no squeaky clutches with a turbo.

BigKutta

I guess just from the butt dyno feel. The turbos I've driven certainly have a lag that's greater than the Supercharger lag (minimal). I'm just impressed with this surpercharger's near linear output when i hit the gas. Again, this is all from feel from my persepective, not based on charts, etc.

Force-1

I love the SC motor in my S5 and Q7; however, I would be better off with a turbo where I live. Albuquerque sits at 5400', and a turbo maintains better boost at elevation than a supercharger.

gsobol

Actually, this may be the effect of Roots type supercharger. These are not as efficient as Centrifugal superchargers (effectively similar build like turbo). I think Audi engineers chose this type of supercharger for it's quiet operation and ease of packaging. the goal was to get the blown V6 to feel like a naturally aspirated V8. With that design come some compromises, such as a lower efficiency at altitude. Turbos and centrifugal superchargers are much more efficient at altitude, however they do loose boost as well due to aerodynamics. You can only spin them so fast to produce the boost at altitude, before you start hitting over-spin. Similar problems that propeller driven aircraft face with increased altitude.

But you right. I think the car would have a closer feel to being at sea level if it had a turbo (twin preferably )