Archive

Posts Tagged ‘VW’

Quattro Formaggio

December 20th, 2009 Comments off

For 37 years, I lived in the south.  (And technically I still do, though most would call my current locale the Mid-Atlantic.)  And in the south, we only get snow once – maybe twice – a year.  And when we do, it’s typically an inch or two (and the governor still usually declares a state of emergency).  Despite this, all three vehicles in my household’s garage have all-wheel- (or 4-wheel-) drive.  I’ve insisted on it.

Now, many folks believe all-wheel-drive is only useful in snow or mud (or otherwise slippery conditions).  I recall about 8 years ago, when I test-drove a VW Passat, I asked the salesman about 4Motion – Volkswagen’s all-wheel-drive system.  His reply was, “You can’t get that down here!  Those are only for up north!”  (…We then went to the Audi dealer and bought an A4 Avant – with Quattro all-wheel-drive – instead.)  And sure, the biggest advantage for a vehicle in which all 4 wheels are driven comes when the weather gets treacherous.  …I’m thinking about this now, because I recently had the opportunity to drive through the middle of The Blizzard Of ’09.  It took 6 hours to go what is normally a 2-hour drive.  Toward the end, I saw rear-wheel-drive cars pirouette across icy bridges, front-wheel-drive cars struggle to exit nearly level parking lots, and even an overturned tractor-trailer.  Overall, I probably witnessed over 50 vehicles nosed into a guardrail, stuck on the shoulder, or otherwise scarred and motionless.  (Quiz:  What do you think the car was that stood out to me out as being the most unusable in the snow?  Answer at the end of the post.)  The A4 soldiered on, as if the event were simply a light rain.

Audi Ski JumpOf course, an AWD vehicle isn’t the only way to handle snowy roads.  A capable driver with a front-wheel- or even a rear-wheel-drive car (especially with a limited-slip differential) and proper tires can maneuver quite well.  (An even smarter driver may decide to stay inside and enjoy some hot buttered rum!)  But physics dictates that the more contact-patches moving the car along, the more likely it is to move at all.  (Stopping is a different matter.  All cars have 4-wheel-brakes.  Unfortunately, it’s the loose nut behind the steering wheel that is often the weak link!)  The fact that I saw a few 18-wheelers (with two driven axles, totaling 8 wheels) spin their tires and go nowhere on the slightest incline testifies to the road conditions 2 nights ago.

But what about the 99% of the time when you don’t need all-wheel-drive?  I mean, doesn’t it just add weight and inefficiency?  Well – yes, it does.  But, it’s still worth it.  Drive a front-wheel-drive car near the limit – try to accelerate while turning.  The front-end will just plow (that is, understeer, or in NASCAR-speak:  push) to the outside of the turn.  A rear-wheel-drive car is much more sporting in that regard, but apply too much power and the opposite effect occurs:  oversteer, when the rear-end breaks loose.  But an all-wheel-drive car can make even the worst driver look talented.

And what about that other 1% of the time when the weather dictates that an all-wheel-drive system might be beneficial? Absolutely worth the price paid (which is usually no more than a DVD or a navigation system).

QUIZ ANSWER:  I saw several of the latest generation Dodge Magnum wagons during my drive.  I think every one of them was stuck.  If you live north of the US/Mexico border, you probably shouldn’t buy one.

Single File, Please

December 6th, 2009 Comments off
VW L1

Volkswagen L1 Concept

Back in September, at the 2009 Frankfurt Auto Show, Volkswagen displayed its L1 Concept vehicle, claiming an astounding fuel economy of 170 mpg.  How did they do it?  Well, they start off with an ultra-efficient hybrid powertrain comprised of a 0.8-liter turbodiesel (TDI, which I discussed here) and a 10kW electric motor.  (No plug needed here!)  They use an ultra-light-weight body of carbon-fiber and plastic.  And they designed it with an incredible drag coefficient (Cd) of 0.195.  Improving on the aero efficiency (a topic I discussed here), is a small frontal area, accomplished by arranging the two occupants of the L1 in tandem.  (Remember, the amount of power needed to overcome the air resistance when moving a vehicle is directly proportional to the frontal area, just as it is to the Cd.)

Nissan Land Glider Concept

Nissan Land Glider Concept

At the Tokyo Motor Show a little over a month ago, Nissan unveiled its Land Glider concept.  Unlike VW’s L1, the Land Glider is a pure electric vehicle, with two motors powering the rear wheels.  (No word on the energy efficiency of the vehicle.)  It also has novel technology, such as the handling-improving capability of leaning in the corners, and crash-avoidance sensors to maneuver the vehicle around objects with which it would otherwise collide.  The Land Glider also (presumably) is aerodynamically efficient – at least it looks that way.  And like the L1, this is achieved partly through the use of tandem seating.

Could this be the shape of things to come? Two-passenger vehicles have existed for a while, from sporty roadsters (like the Miata) to econo-boxes (like the Smart).  So, why not cut the frontal area down, and place the passengers fore and aft?  Is this just too impractical – or too unusual – for the average consumer to handle?  With many pushing for purpose-driven vehicles (rather than cars that can do everything, like what most of us drive today), we may eventually see a lot more variety in the types cars on the market.  It’s not so far-fetched that we may see a derivative of the L1 or Land Glider for sale in a few years.  And although tandem seating doesn’t really lend itself to a romantic time at the drive-in, it certainly can play a part at improving the fuel-economy once the wheels are in motion.

Questions

September 9th, 2009 Comments off

A friend of mine recently asked me a few car-related questions via email.  I thought I’d answer them here.

Why can’t I get a Jetta turbo diesel sport wagon?  There are waiting lists for this car all over the country.  Seems crazy. Well, that’s easy.  It’s because the demand has exceeded supply.  Ah, but you knew that.  …It’s ironic: wagons haven’t been very popular in the U.S. in recent years, and neither have diesels (which I spoke about here).  But VW can’t seem to build enough Jetta TDI Sportwagens to satisfy the American market right now.  I chalk it up to the fact that folks are finally realizing the benefits of smaller vehicles, as well as modern diesel engines.  In concluding that a wagon is a perfect replacement for their SUV, they’re finding there’s really only one vehicle that fits the bill – the VW sportwagen really doesn’t have any competition out there right now.  I’m still not sure what it will take, though, for them to increase production (are they already at capacity?) or shift more of the allotment to the U.S.  (As a curious sidenote, I think I read somewhere that the vast majority of VW Jetta Sportwagens that are ordered are of the TDI variety.  I may be making that up.)

So which brands of car are we loosing due to the GM collapse?  Which cars will we never see again and good riddance and which one’s would it have been nice to keep around. We’re losing Pontiac – they’re vanishing completely.  And good riddance to them.  We’re losing Hummer – that brand is being sold to Tengzhong Heavy Industrial Machinery.  It’s not clear to me if we’ll continue to see the brand in the U.S., but my guess is that we won’t.  And that won’t be a loss, either.  Saturn also gets the axe, although to a lesser degree – it is being sold to Penske Automotive Group.  GM will continue to supply Penske with the Aura, Vue, and Outlook for a couple of years, and other models will eventually be outsourced from other auto manufacturers.  (Unfortunately, the Saturn Sky didn’t make the cut.  This 2-seat, rear-wheel-drive roadster, sharing the Kappa platform with the Pontiac Solstice, is a completely irrational, impractical automobile – but it’s beautiful, sporty, and is a big loss in my mind.  The Outlook is a good vehicle, but might be a little too diluted, being virtually the same as the GMC Acadia, Buick Enclave, and Chevy Traverse.)  The Penske deal is an interesting one to me, since it’s different than anything else I’ve seen in the auto industry.  Another interesting deal is the sale of Saab to Swedish supercar-maker Koenigsegg along with Beijing Automotive Industry Holdings.  My guess is Saab will remain, but its focus will shift to the Asian market, and they may vanish from the U.S. altogether.  Unfortunately, Saab never really caught on in the U.S. – and that’s our loss.  Finally, GM may be selling off its Opel unit, though it’s not clear at this point.  Doesn’t really affect us over here, though…

And lastly why do Americans hate the hatchback?? I don’t know.  Call it an extension of the anti-wagon sentiment.  Although, hatchbacks have been successful here in the past.  The original hot-hatches, the Honda CVCC and VW GTi, were hugely popular.  And the Ford Focus hatchback sold well here, I believe.  I’m excited for the 2011 Ford Fiesta (in hatchback form) to make its arrival.  What do you think?

2011 Ford Fiesta Hatchback

2011 Ford Fiesta Hatchback

Rudolf’s Invention

August 20th, 2009 Comments off

In 1892, Rudolf Diesel invented the compression-ignition (i.e., diesel) engine.  The big difference between diesel engines and gasoline engines is that gasoline engines are typically of the spark-ignition type, relying on a spark-plug to ignite the air/fuel mixture, whereas compression-ignition simply relies on physics to cause the air/fuel mixture to ignite when it is compressed to around 5% of its original volume.

VW Jetta TDI Sportwagen

VW Jetta TDI Sportwagen

Diesel engines are significantly more efficient than their gasoline-powered counterparts, and have enjoyed more popularity in most parts of the world.  Unfortunately, the U.S. is not one of those parts.  Although a few manufacturers have offered diesel engines in their light-duty vehicles in the past, about the only mass-market diesel vehicles you can find in the U.S. today are powered by Volkswagen’s TDI technology.  It seems other manufacturers would follow VW’s lead, given the sustained success of the TDI engines.

What’s the problem here?  Maybe it’s marketing: American consumers still remember the horrible diesel engines of a few decades ago, and think of them as noisy, polluting, and slow, when in fact modern diesel engines are quiet, clean, and powerful.  Maybe it’s cost – diesels generally cost a tad more than their gasoline counterparts; however, diesel engines are usually built “tougher” to withstand higher compression ratios, and frequently have greater lifetimes as a result.  And then there’s the efficiency benefits.

…In a past season of Top Gear, the hosts had a contest to see who could drive from Basel, Switzerland, to Blackpool in the UK, driving any car of their choice, but using only one tank of fuel.  Jeremy Clarkson figured it couldn’t be done, so he chose a car that would actually be enjoyable: a Jaguar XJ6 TDVI (diesel) with a fuel economy rating of 35 mpg, and a theoretical range of 655 miles.  James May chose a Subaru Legacy diesel with a rating of 50 mpg, and a theoretical range of 706 miles.  Richard Hammond chose a VW Polo Bluemotion with a 3-cylinder 1.4L engine that gets 74 mpg, but equiped with only a 10-gallon tank.  Before setting off, they properly adjusted their tire pressures, and (in the ultimate display of hypermiling) even sealed the body-seams with tape!

The result?  Richard arrived first, followed by Jeremy, who drove like a bat out of hell with the A/C and all accessories on to demonstrate that it couldn’t be done – proving himself wrong in the process.  …Captain Slow didn’t quite make it.  But, it was an excellent demonstration of the efficiency of diesel vehicles.  Unfortunately, none of these cars are available in the United States.  What will it take to change this?

Doppelkupplungsgetriebe

July 5th, 2009 Comments off

I noticed in the mid-1980s, about the time I became of legal driving age, that cars with manual transmissions get slightly better fuel economy than their automatic transmission equivalents.  I was surprised recently to find out that this wasn’t common knowledge.  And I’ve long wondered, what if we all drove stick-shift?  How much fuel would that save, given that nearly 3/4 of the vehicles sold in North America come equipped with automatic transmissions and the associated 1-2mpg penalty?

A friend recently asked me, why are automatics less efficient?  Now, automatic transmissions are one of the most mysterious components on a vehicle to me.  Inside the transmission are a collection of planetary gearsets, clutches, bands, hydraulic pumps, plates, valves, modulators, and pixie dust that make the car go.  All of this is typically heavier than the components of a manual transmission, and uses a portion of the engine output in its operation.  But the thing which enables the automatic transmission to work (besides the pixie dust) is the torque remover converter.  This is the device that provides a fluid coupling between the engine and transmission, and allows your engine to idle while you’re sitting still with your foot on the brake pedal … and which also accounts for some of the efficiency loss in automatics.

A proper manual gearbox is much more straightforward:  You have a clutch which engages/disengages the connection between the engine and the transmission via your left leg, and gears on the input shaft (from the engine) which engage with gears on the output shaft (to your wheels, through a differential).  No pumping losses, inefficent fluid couplings, pixie dust, or other such nonsense.

Green Technology?

Green Technology?

Blurring the line between manuals and automatics, dual clutch transmissions (DCTs) have been introduced to the mass market in recent years.  VW‘s is called DSG (direct shift gearbox); Audi calls it S-tronic; BMW calls theirs DKG, abbreviating the German “doppelkupplungsgetriebe” (literally, double clutch transmission); Porsche‘s is called PDK (Porsche DoppelKupplungsgetriebe).  These are effectively manual transmissions in which a computer does the shifting for you.  (Of course, they also have a manual mode, allowing the driver to be more involved in the process.)  Note, these boxes are vastly different than the “manumatics” of the past, such as Dodge’s “autostick” and Porsche’s “tiptronic,” which are actually planetary gearset, torque converter-based automatics that pretend to let the driver be in charge.  The new gearboxes are both more efficient than traditional automatics, and often even higher performance – faster shifts – than even the best driver-actuated manuals.  This is achieved by essentially encasing two manual transmissions (one for even gears, one for odd) in a single case – hence, the “dual” nature.  By the computer anticipating and preselecting the next gear to be chosen, shift-time is dramatically reduced.

Could these be a replacement for traditional automatics?  In my opinion, YES, and I back that up with an anecdote: A friend of mine recently bought a DSG-equipped VW Jetta.  He told me it was an automatic, for which I belittled him.  Upon seeing it, I realized it was a DSG and informed him of that fact.  He had no idea, even after driving it a few thousand miles.

A recent article in Automative Engineering International (a publication of the Society of Automotive Engineers) mentions that such gearboxes have been around since the early 1980s, but have only recently become commercially viable because of advances in electronics, sensors, and computing power on-board the vehicle.  New technology has enabled better fuel efficiency AND better performance.  …Ain’t technology great?!