Volkswagen Concept Car Averages 262 MPG

coolnumbr12 writes "The Volkswagen XL1 averages an amazing 262 mpg, and although it may never hit streets in the United States, the technology behind the car could impact future Volkswagen vehicles. The keys to the incredible mileage in the Volkswagen XL1 were reducing the weight of the vehicle and eliminating wind resistance. The XL1 only weighs 1,753 pounds — that's more than a thousand pounds lighter than the Toyota Prius, which weighs in at 2,921 pounds. The wheels on the Volkswagen XL1 are as thin as road bike's and wrapped in custom Michelin rubber. The XL1 chassis is a single piece of molded carbon-fiber, and has a drag coefficient of only 0.189 – similar to a bumblebee."

Comments

We need a new class of 'ultralight' cars

[BroadbandBradley]

We have very safe cars but they're also very heavy as a result. Granted gains can be made with expensive and exotic materials, but how about CHEAP and LIGHT cars that could be had for just a few grand, and get 80-100MPG? before you think no-one would want to drive something without airbags and side impact beams and crush zones, what about motorbikes? I really think it would be a big hit with consumers who don't wish to be exposed to the elements or have to balance a motorcycle, but would opt for BASIC transportation with a 500cc motor, 3 or 4 wheels, and enclosed cab. Current safety standards for 4 wheeled vehicles make basic and light car not an option.

Re:We need a new class of 'ultralight' cars

[140Mandak262Jamuna]

That is the concept behind Tata Nano. It is very cheap and you could barely call it a car. But its CEO (at that time, not sure who is running the show now) Ratan Tata said "It is not an unsafe car. It is a safe motor cycle with four wheels and a roof" (I am paraphrasing). In India it is common to see an entire family, dad+mom+two+kids all piled up in one motor cycle or a scooter dodging potholes and weaving in out of traffic. Yes, such cars exist. But it is very unlikely to pass any safety test in USA/Europe/Japan/Korea.

Re:We need a new class of 'ultralight' cars

[CAIMLAS]

If the goal here is to 'save money' or 'save resources' by having a high MPG/k/L, I don't really get the point of these 'ultra safe' cars.

I'm sorry, but I've seen dozens of what would've been considered 'minor fender benders' even 10 years ago result in the vehicles being irreparably totaled. I've personally been hit twice where the other late-model vehicle was put on a flatbed and (likely) scrapped: in both instances, I barely even noticed the impact in my 1980s-vintage vehicle, I had -maybe- $250 in total body damage each time, and nobody was hurt. These modern cars, to the exception of full size trucks, seem to lose pieces if they hit so much as a slightly sticky traffic cone. Considering the cost and resources that go into making them, and how easily they're totalled, I can't see this as a win for anyone but the automotive makers and insurers (through larger premiums).

Re:We need a new class of 'ultralight' cars

[ldobehardcore]

As far as I know, modern cars are designed to crumple, and smash externally in order to dissipate shock in an accident as much as possible.

For instance, if you have a very rigid-bodied vehicle and a crumply-bodied vehicle, you'll most likely experience more acceleration in an accident with the stiff bodied vehicle, as the crumply vehicle takes more time to come to a complete stop. Going from 60mph to 0mph in 100 milliseconds exerts ~27.34G on the occupant. If you can double the period of acceleration from 100 milliseconds to 200 milliseconds, you can half the G load to ~13.67G, which is much more survivable.

I don't know how much the crumple zones and pliability of the frame contribute exactly, but in life or death situations every little bit counts, as far as the highly risk averse public is concerned.

Re:We need a new class of 'ultralight' cars

[mjwx]

As far as I know, modern cars are designed to crumple, and smash externally in order to dissipate shock in an accident as much as possible.

This x 1000. Modern cars are designed to ablate and crumple as much as possible in order to protect the meat that crashed it.

People without a clue as to how physics works in a car crash often lament that their 19-dicket-2 car hardly gets a scratch in a low speed collision and completely forget that in a mid speed collision the car also harldy suffers a scratch, but the driver and passengers ended up going to the morgue.

The more bits that come off the car, the more crumpled it looks the less kinetic energy went into the occupants.

Re:And what's that in metric?

[Trepidity]

Which of the two widely used metric standards do you want? ;-)

If you're from one of the countries that uses the km/L measure (Netherlands, Denmark, Japan, Korea, etc.), then this Volkswagen prototype gets about 110 km/L.

If you're from one of the countries that uses the L/100km measure (Germany, Italy, Australia, etc.), then this prototype uses about 0.90 L/100km.

Neat, but unsafe.

[Anonymous Coward]

Given the drag coefficient, I assume this car exhibits Laminar flow. This can get disrupted by external factors (say getting passed by a buss) and result in localized turbulent flow. This would drastically increase the drag on one part of the car, causing a sudden unexpected side load, likely causing a turn (into the passing bus). An airplane bouncing around is not much of an issue, but when your car moves over 6 feet sideways on the freeway unexpectedly, it can be rather bad.

Generally maximally aerodynamic cars are not safe. They may not have gotten to that point, or may have cleverly worked around the issues, but given the lack of side mirrors, I think mileage was the priority over safety here. Its a neat technical feet, but as mentioned in the article, its dangerous in multiple respects.

Re:Proper units

[Anonymous Coward]

A mile is 8 furlongs and a gallon is 8 pints. So this car can do 262 furlongs per pint. That's quite an achievement considering it's mass is 125 stones.

Re:Of course it won't hit the US

[Chas]

Basically. The vehicle's so lightly built that a fricking DODGE OMNI will tear through you like you were toilet paper.

Over in Germany, if someone spatters themselves on (or by the side of) the road, it's the driver's fault for not knowing their car.

Here in the US, it's the manufacturer's fault for not making the car crash-survivable.

Re:One problem

[Cosgrach]

There is absolutely NOTHING wrong with rear wheel drive. (unless you don't know how to drive to begin with)

Re:Metric Units.

[ackthpt]

No it's because we had a working system and didn't need a new one. Long may it live!

Yeah... Nothing I enjoyed more than doing conversions of miles, feet, inches, tenths of inches, pounds, ounces (avoirdupois), gallons, fluid ounces and all that muck during Math, Chemistry and Physics classes, all the while there were these lovely decimal systems just itching to make everything much easier.

Not really

[Solandri]

From T3rdFA:

The XL1 has a 27-hp electric battery, which can propel it about 31 miles on its own, up to 62 mph. It can fully recharge, Volkswagen says, in an hour and a half. The maximum speed overall, using the full hybrid drivetrain, is 94 mph. Thereâ(TM)s a 2.6-gallon fuel tank, which lets the XL1 achieve a total range of 310 miles

So subtract the 31 miles on battery, leaving 279 miles on gas, and it can get 107.3 MPG on gas alone. The 262 MPG figure probably comes from a shorter test drive where the first 31 miles were on battery, the remainder on gas, then attributing the total distance to gas. Which if I did my math right is a 52.5 mile run.

Thing is, if you're going to cheat this way, why not just make it a 32 mile run and claim your car gets over 3400 MPG.

It's also worth pointing out that outside of research, these ultra-high mileage vehicles are rather pointless. MPG is the inverse of fuel consumption, so higher MPG means smaller savings. e.g. Consider a trip of 300 miles in a variety of different cars:

15 MPG SUV = 20 gallons consumed
25 MPG sedan = 12 gallons consumed
50 MPG hybrid = 6 gallons consumed
100 MPG research car = 3 gallons consumed
300 MPG super-car = 1 gallon consumed

So if you consider a switch from an SUV to a super-car on a 300 mile trip, where exactly do the 19 gallons of fuel saved come from?

8 gallons saved comes from the 10 MPG jump from 15 to 25 MPG.
6 gallons saved comes from the 25 MPG jump from 25 to 50 MPG.
3 gallons saved comes from the 50 MPG jump from 50 MPG to 100 MPG.
2 gallons saved comes from the 200 MPG jump from 100 MPG to 300 MPG.

The biggest fuel savings comes from the low end of the MPG range. The smallest savings from the high end. Or in other words, in a SUV to super-car switch:

42.1% of the fuel savings comes from the 15-25 MPG jump
31.6% of the fuel savings comes from the 25-50 MPG jump
15.8% of the fuel savings comes from the 50-100 MPG jump
10.5% of the fuel savings comes from the 100-300 MPG jump

Diminishing returns says the cost-effectiveness of improving mileage rapidly drops off above about 50 MPG. If we want to reduce overall fuel consumption, we should be concentrating on ad campaigns to get people out of gas guzzlers into smaller cars. Not concentrating on designing ultra-high mileage vehicles.

Re:And what's that in metric?

[Attila Dimedici]

You are missing his point. Since you apparently are someone who uses U.S. Standard Units, I will convert his point to those. It is easier to compare the gas efficiency of two cars if you use Gallons(Liters) per 100 Miles(Kilometers) than it is to do so using Miles(Kilometers) per Gallon(Liter). For example using mpg (or kpl) it appears that a vehicle that gets 40 mpg is as much better than a vehicle that gets 20 mpg as a vehicle that gets 20 mpg is better than one that gets 10 mpg. However, if you convert that the Gallons/100 Miles(gp100m) you discover that a vehicle which gets 10 mpg gets 10 gp100m, while a car that gets 20 mpg gets 5 gp100m and one that gets 40 mpg gets 2.5 gp100m. Meaning that you save 5 gallons per 100 miles traveled when you go from a vehicle which gets 10 mpg to one that gets 20 mpg, but you only save 2.5 gallons per 100 miles traveled when you go from a vehicle that gets 20 mpg to one that gets 40 mpg.
Understanding this makes clear how much it is costing us to make ever smaller incremental changes in improvements in gas usage by vehicles. Paying attention to that will allow us to more readily recognize when further improvements in fuel efficiency are not worth the cost. It is called the law of diminishing returns, a law to which we as a society pay too little attention.