Which is better maintenance cost-wise? I had a GT Volvo that gobbled up my wallet as I went through two turbos in six years.

 

I believe the turbo is more efficient therefor the engine has to work less to make power and I would think that helps keep the stress off the car.

 

I don't thing there's any categorical answer to that question. There's nothing inherently more or less reliable about a turbocharger or a supercharger. A badly-designed unit of either type will be a pain, a good one won't fail. Turbochargers use exhaust gases to spin the unit, so they are efficient, but there are high temperatures involved and there can be power lag. However, turbochargers came from the aviation industry, so the technology isn't a problem. Superchargers run off the crankshaft, so they use some power to produce more power. Maybe less efficient, but no lag.
I wouldn't worry about the difference; I would pay more attention to the particular car and its reliability record.

 

I remember hearing that the Turbo mini's have less lag then the supercharged ones.

 

You heard wrong...

There is no lag with the supercharger.

There is lag with the twinscroll turbo, but it's minimal...

 

What I heard was that the R56 had more low end torque the the R53 off the line.

 

Gear driven superchargers were first experimented with in the bi-pane era around 1914. The first production application in the US was by Prat and Whitney in the 1927 Wasp.... Both technologies trace thier origins to the aeronautic industry.....

Turbos are more efficient thermodynamically, but really cook the craap out of parts in the engine compartment (just look at all those melted hood scoops). while the supercharger is less thermodynamically efficient, it places a mechanical load on the accessory belt. But thermal stresses are greatly reduced. Personally, I think turbos take a little more care, but both technologies have come a very, very long way.

You can look around and find examples of both technologies that were problematic (Saab 900 turbos cooked with great regularity, as an example). But there are also tons of examples of cars where the turbo isn't what one worries about. The turbo Prince engine is new enough that the jury is still out, but initially it seems that the turbo isn't the problem with it.

Matt

 

That is true. The torque curves are different; it's shifted to the left on the R56, it kind of peters out at higher RPMs . The lower end of the twinscroll turbo kicks in at 1500 RPM's, hence low range torque. Makes the R56 a better around town car, but with any turbo there is a little lag.

 

Just read a book my father in law loaned me about this. It's amazing the technology that initially found it's way into automobiles in the 20's (superchargin, overhead cams, independent suspensions, etc, etc); it's also amazing some of the performance barriers that were passed--also in 1927, the 200mph barrier was passed at Daytona, and in 1935, 300 mph. To me, it's mind boggling...

 

IIRC, not only does the R56 MCS have more HP and torque than the R53, it also gets much better gas mileage.

The Alfa Romeo P2 had twin supercharges (one into the other) and won the world championship in 1925.

 

In either case you are running a pressurized engine, hence more stress on the engine and its internals. If the tc/sc is designed correctly and the engine and its components designed to take the extra stress and environment then it shouldn't be a problem.

 

It's all into how it's designed... that's why you see those early 90s Civics running reliably with 300+ horsepower. I'm sure the MINI is not as overengineers as those cars, but so far at 20,000miles, there is no hint of failure. Running smooth and strong, and I commute within a city!