Why so few new supercharged cars?

Lots of turbo this-n-thats, but few superchargers.

Turbos have lag–even the Saturn Sky Redline has a noticable lag that drove me nuts when I drove one. I know a SC is always “on” and so saps power even when not in use, but is the effect really that bad considering you get your boost now when you want it? If I want a gas-sipper I’ll buy a non-boosted car and drive it like an old man. But if I’m in a 2-seater I have a different agenda, and I don’t want to wait for my boost.

You figured it out. Gas mileage is the problem.

Plenty of people want cars that are powerful and fun, yet still economical to drive. That’s why there are a lot of smallish cars in the $25,000-$35,000 range with turbochargers - like the Volkswagen GTI.

Ford is now selling an F-150 with a turbocharged V6 that outperforms their conventional V8 in power, torque, and efficiency.

Even BMW now uses twin-turbo inline sixes and V8’s in their high-end models. Again, efficiency without sacrifice in power is the reason. The lag in these is minimal, I’ve driven them several times.

High-performance naturally-aspirated engines are fast enough these days for any normal person (who needs more than 340 hp in a two-seat sports car?), but given current fuel prices, their poor mileage matters to a lot of people. Turbochargers provide a way to improve efficiency with a minimal ( if any) penalty in performance. Superchargers produce extra power (which is unnecessary), and kill mileage even further. They’re just the wrong side of the spectrum in today’s world.

Don’t forget that, independent of consumer preferences, many companies are also obliged to maintain a certain minimum fuel economy due to government regulation.

Even naturally-aspirated, traditional sports cars (the Nissan 370Z, Porsche Cayman, etc.) are selling poorly - slapping on a supercharger and reducing their mileage even further would be a bad business decision.

Personally, I like the sound and feel of a turbocharged engine. Modern turbo systems have minimal lag - the Saturn Sky could very well just be a turd of a car, which would not surprise me. I really liked the engine in the Volkswagen GTI, which I test-drove just last week. The lag was just enough to remind you the turbo was there, but not enough to be annoying.

For people who must have instant power at the expense of all else, there are plenty of aftermarket tuners who will gladly bolt a supercharger onto pretty much any car you’d like.

Basically what Absolute said. In addition to being “on” all the time, mechanical-driven superchargers are just less efficient overall because they’re a load on the engine, whereas turbochargers mostly use energy that would otherwise be wasted.

I suspect a big reason why superchargers were popular in production cars for a while was the same reason why they’re more popular in the aftermarket-- it’s relatively easy to just basically bolt a supercharger onto an existing engine in an existing engine bay. But you have to either plan to accommodate a turbo from the start or do some major modifications to add one in. But these days more engines are designed from the ground up with at least optional turbos in mind, so there’s a lot less call for superchargers.

They require premium fuel, too.

The VW example is a good one.

The TSI engines they use are a combination of Turbo and Supercharger.
The result is great power and economy from tiny engines.

I’ve driven the Skoda Yeti 1.2 Tsi (they are a VW group company) and it is phenomenal.
plenty of power and over 40mpg.

I liked the car so much I’ve ordered one, though I’m going for the Turbo Diesel version which will give me 60 mpg

There’s also not that many places you can actually drive them at anything like their full potential, unless you live in parts of Europe with an Autobahn or equivalent thereof.

Blown engines are more common than you think. The Corvette ZR1, Cadillac CTS-V, upcoming Camaro ZL1, Mustang GT500, Australian Ford Falcon, on the European side VAG has gone to a supercharged 3.0l V6 on a wide variety of their new products ranging from the S4, A6 and A8 to the (Chinese market) Porsche Cayenne and will probably be in more too, and Jaguar-Land Rover has used supercharged versions of their excellent AJ-V8 engines for a while. Toyota also has a few supercharged variants of their GR-series V6 on various models in the Japanese and Australian market.

You’ll note that there are a few common theme here.

  • All the engines are “V” engines. Because a Roots type supercharger fits quite neatly in the “V” valley right on top of the intake, it makes for a very nice package in the engine bay, much more so than a turbo. Turbo-in a V engine is somewhat tricky, most companies use twin turbos, one for each bank of cylinders, and this usually results in a mass of jumbled air piping. The old twin turbo V6s on Audis and 300ZXs were maintainance nightmares. I’m also told that they cause problems with NOx emissions due to the way the cylinders fire, although I can’t claim to understand that particular argument. The new BMW twin turbo V8s have a unique layout - intake is on the outside of the V while exhaust and turbos are on the inside. I can’t imagine the kind of problems those suckers will have out of warranty.

  • Modern Roots type supercharged are very efficient at idle. A bypass valve in the intake tract basically allows the blower to freewheel when the engine is at low loads, meaning that at idle, the power draw of the blower is negligible. The Audi supercharged V6 cars are much more fuel efficient than the V8 models they replaced while offering similar or superior power and torque. A more important metric than power draw is heat produced from the compression process, and in this respect, Roots blowers also produce very little heat when not under load. All the above-mentioned cars use this type of blower.



The other common type of supercharger is the twin screw type. Without going into too much detail, a twin screw blower is quite a bit more efficient (read produce less heat) under load than the Roots type, so are great for power, but do not have the bypass valve and thus are quite inefficient under low loads. Last generation Mercedes AMG cars used the 5.5l V8 with this type of blower, as did the Ford GT super car. They are…powerful, but quite the gas guzzlers. Twin screw superchargers are popular upgrades for cars already equipped with Roots blowers, if one is looking for more power at the expense of worse fuel economy.

So I would disagree with Absolute. Superchargers offer all the advantages of turbocharging, are just as efficient in terms of power, and also offer more efficient packaging and less need for screwy exhaust and intake piping, especially in V-type engines. Car manufacturers are increasingly turning to supercharging, with Audi being the prime example of a marque that has actually gone from turbos to superchargers on their newest models.

The Yeti does not use the Twincharger engine, they only made one Twincharger engine, it’s a 1.4l and was only used in a few VW models around 05-06. It ultimately proved too complicated and expensive.

Mercedes still use supercharged engines. The C180 puts out about 150bhp and gives 40mpg, while for the C200 the figures are about 180bhp and 39mpg.

In 2009 the 180/200 switched to a turbo direct injection engine and are badged “CGI” instead of the old “Kompressor”.

Oh hello forum poster Inigo Montoya. You are correct in your preference for supercharged vehicles. May I suggest a Ford Mustang GT500? The last generation model with the iron block engine is coming up for quite reasonable prices on the used market.

With the money you save over buying new, you can then pick yourself up a Hellion twin turbo kit. One additional advantage of a supercharger that I didn’t mention is that superchargers essentially operate as a “multiplier” of the pressure differential between the intake and output air, so when you have two turbos blowing into the supercharger, the supercharger applies additional compression to the compressed output of the turbos and you get the magic of compound boost!

aha! you are right. They just didn’t change the suffix. They still call the engines “Tsi”
but now they are sophisticated turbos only with direct injection.

Ignorance fought (and it is still a cracking little engine)

But what I really want is a MkIV Toyota MR2. The concept is an affordable, tiny, powerful, agile platform for a SC 4-banger. I want 200 HP pushing not much more than 2000 lbs of car. And this thread is me bitching.

I think it is partly the way people drive. Turbo lag is a problem passing on a 2 lane road. When you are stuck behind a slow poke you wait to get over the hill or around the bend. The more instant power you have, the less open road you need to get around them safely. Same deal with the 16 valve DOHC 4’s I have been driving. It takes too long to get the rev’s up. But too many people or their car lack the guts to pass. Instead, they fall in behind so closely to force anybody else to pass both. Before long, you have a string of 4-5 and passing is dicey.

If you aren’t going to pass, you won’t demand a car able to.

May I suggest you test drive a Ford with an EcoBoost engine? The EcoBoost is a turbo supercharger, and you’ll see that lag is pretty much eliminated versus older turbo superchargers.