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Formula XL1 can travel up to 22 miles on battery power alone

We don't usually think of the Qatar Motor Show as a place where major automotive product announcements/advances are made, but Volkswagen used the show to unveil the latest in its line of vehicles aimed at extracting the ultimate mileage out of a single gallon of gasoline.

The German company today announced its Formula XL1 concept car that makes use of a two-cylinder turbodiesel engine, hybrid electric motor (with a lithium-ion battery pack), and a seven-speed dual-clutch transmission. The Formula XL1 has enough juice from its lithium-ion pack to travel for 22 miles on battery power alone, and gets a total combined fuel efficiency rating of 260 mpg.

When the subject of gasoline electric hybrids is brought up on DailyTech, there quite often is chatter from our European readers stating that they have been getting similar -- if not better -- mileage from turbodiesel engines for years in similar vehicle types. So it's nice to see that VW is taking the best of both worlds with this new vehicle concept. 

And it's not just the turbodiesel-electric hybrid powertrain that gives the Formula XL1 its impressive fuel economy; the vehicle also makes use of lightweight carbon fiber reinforced polymers for the body panels to further reduce weight. The driver and passenger also sit in a tandem arrangement -- the passenger sits slightly aft of the driver and behind the driver's seat (think McLaren F1) -- which allows the Formula XL1's body to cut through the wind more efficiently, which also improves overall fuel efficieny. 

There is no word if or when such a vehicle will be put into production, but we're sure that there are more than a few hypermilers here in the United States that wouldn't mind getting their hands on one.

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Efficiency ratings...
By Marlonsm on 1/25/2011 5:27:21 PM , Rating: 5
total combined fuel efficiency rating of 260 mpg.

Cars that run on battery alone before using fuel can easily mess up that rating. It would be interesting if they started measuring that after the battery run out of juice.
For example, if they run 40 miles with that car to get the rating, only the last 5 will have the engine on, actually using fuel, and the rating given would be 8 times higher than it should.

IMO, cars like that should have 2 ratings, one in miles/Kwh, for when its only using the battery and one in MPG, measured after the engine starts.

RE: Efficiency ratings...
By Jeremy87 on 1/25/2011 5:36:04 PM , Rating: 2
Wonder where they will go once they have electric cars at 8 mpg.

RE: Efficiency ratings...
By Jeremy87 on 1/25/2011 5:36:58 PM , Rating: 2
DailyTech made my infinite sign into an 8...

RE: Efficiency ratings...
By petpeeve on 1/26/2011 12:02:04 AM , Rating: 4
Since childhood, DailyTech only had 4 fingers on each hand. Hence, 8 is effectively infinity for it. Poor child.

RE: Efficiency ratings...
By ekv on 1/26/2011 3:29:50 AM , Rating: 2
And you thought octal died with DEC...

RE: Efficiency ratings...
By Visual on 1/26/2011 3:59:56 AM , Rating: 2
There is no "8" digit in octal...

RE: Efficiency ratings...
By JediJeb on 1/26/2011 11:54:54 AM , Rating: 2
That would be nonal if it ends in 8.

RE: Efficiency ratings...
By DrSpaceman on 1/27/2011 12:29:48 AM , Rating: 2
wow, don't know who's the biggest nerd... you guys or me cause I actually followed that...

RE: Efficiency ratings...
By Rasterman on 1/25/2011 5:37:31 PM , Rating: 3
Anyone who uses a MPG rating based on driving 40 miles is an idiot. Besides its a concept car, you will never see it, and if a version of it does make it to market, I'm sure the EPA rating will be a fraction of that 260mpg figure just as with the Volt and Leaf.

RE: Efficiency ratings...
By michael67 on 1/26/2011 7:47:41 AM , Rating: 3
Anyone who uses a MPG rating based on driving 40 miles is an idiot.

No this care is based on the challenge of the head engineer at VW, to develop a car that drives 100km on 1L fuel(235 mpg)

The original idea came from the One-Liter Car concept 10y ago
VW unveiled the slick two-seater concept six years ago at a stockholder’s meeting in Hamburg. To prove it was a real car, Chairman Ferdinand Piech personally drove it from Wolfsburg to Hamburg. At the time, he said the car could see production when the cost of its carbon monocoque dropped from 35,000 Euros (about $55,000) to 5,000 Euros (about $8,000) — something he figured would happen in 2012. With carbon fiber being used in everything from airliners to laptops these days, VW’s apparently decided the cost is competitive enough to build at least a few hundred One-Liters.

Old L1 article:

As its build following that concept, i presume this one also drives whit out plug-in support the rated 261 MPG.

Wired has a excellent article about this car.
New XL1 article:

I for one would for sure put this ore cars like it on my short list to replace my GS450h in 2 years time.

RE: Efficiency ratings...
By mars2k on 1/25/2011 6:08:18 PM , Rating: 3
Pretty car check out the original honda insight. The good news here is that is a VDub. I might be able to sit in it without folding myself in half.
I would like someone to explain having a diesel/electric combo and why that is more efficient. Is the combustion engine de-couple from the wheels here is it only driving a generator and keeping battercharged. Thereby keeping the engine running at its most efficient load and rpm. Now if we could get some organic solar cells painted on the surface to charge the battery during that 8 hr period waiting for me to geet off work and drive home.

RE: Efficiency ratings...
By Marlonsm on 1/25/2011 6:51:47 PM , Rating: 1
Usually hybrids have the combustion engine directly coupled to the wheels, having it to act just as a generator, IMO, wouldn't be much of an advancement, as there would be losses putting a generator, a battery and a motor in the way between the engine and the wheels. And that wouldn't be much better than the mechanical transmissions we have today.

What I really want to see are hybrids that use a turboshaft engine as generator, just like the ones in helicopters, but smaller. They are much more efficient than ordinary engines, but couldn't be used in cars so far because they can only operate at a small range of speeds, not suitable for the streets. But very good as a generator.

RE: Efficiency ratings...
By mmcdonalataocdotgov on 1/26/2011 8:08:48 AM , Rating: 2
There is a car manufacturer that released a concept vehicle with twin turboshaft engines. Dang, I forgot who it was. Anyway, remember those things have helacisouly hot exhaust gases, which would melt the cars behind it.

RE: Efficiency ratings...
By Marlonsm on 1/26/2011 9:20:36 AM , Rating: 2
Right after writing that post I watched Top Gear and there they showed that concept, a Jaguar.

I'm not saying we already have the technology to build such a car and sell it as any other. There are some problems to solve yet, the exhaust heat is one of them, but I've already seem concepts that use that heat to generate more power, cooling it in the process.
We aren't there yet, but I would say that in a few years it could be possible.

RE: Efficiency ratings...
By JediJeb on 1/26/2011 12:04:07 PM , Rating: 2
Actually it is much more efficient to have the diesel engine run a generator and then have that power the wheels. This is mainly due to the fact that the engine will always run at the same rpm which is optimized for efficiency. Locomotives have used this principal for decades.

With this configuration you would not need to constantly speed up and slow down the engine if driving in town, it would simply run at a constant rpm like when you are cruising down the freeway. That is why you get better mileage running faster on the freeway than when running slower in town. Also if you are charging a battery when stopped at a traffic light then you are not wasting the energy idling but instead you are storing it up for later use.

RE: Efficiency ratings...
By Marlonsm on 1/26/2011 4:19:59 PM , Rating: 2
You're right.
When I wrote that I was thinking about highway use mainly. But in the city, the engine as generator only has this advantage.

RE: Efficiency ratings...
By YashBudini on 1/27/2011 11:00:14 PM , Rating: 2
This is mainly due to the fact that the engine will always run at the same rpm which is optimized for efficiency. Locomotives have used this principal for decades.

So my question would be what kind of efficiency could an ICE achieve if it's camshafts, FI, etc, were also optimized to behave in this manner? Has anyone attempted this? And wouldn't a CVT allow/improve such a setup?

Locomotives have other issues as well. They require traction motors for startup, no transmission could possibly handle the requirements of an engine pulling xxx freight cars from 0 to 70+ mph. Still, what you said is correct.

A handle of locomotives that remain in yards have transmissions. They are not the norm.

RE: Efficiency ratings...
By YashBudini on 1/27/2011 11:01:33 PM , Rating: 2
Yeesh, handle. I meant handfull.

RE: Efficiency ratings...
By YashBudini on 1/27/2011 11:08:33 PM , Rating: 2
D'Oh! Handful.

RE: Efficiency ratings...
By walk2k on 1/25/2011 7:23:07 PM , Rating: 3
in before:

"its UGLY!!"

"its not safe if you get hit by a bulldozer!!"

"but I need 8000 horsepowers and seating for 30!!"

"global warming is DUMB!!111"

and something about "socalism" and/or Obama...

RE: Efficiency ratings...
By Helbore on 1/26/2011 6:35:58 AM , Rating: 2
You forgot "In Soviet Russia..."

Ok, you rarely see that one any more, but I kinda miss it!

RE: Efficiency ratings...
By shiftypy on 1/28/2011 8:51:24 AM , Rating: 2
In Soviet Russia engine is YOU!!!

ok kinda weak, but you get the point, pushing the car when it breaks down...

RE: Efficiency ratings...
By icemansims on 1/26/2011 11:12:58 AM , Rating: 2
You forgot Godwin's Law.

RE: Efficiency ratings...
By Major HooHaa on 1/26/2011 8:38:36 AM , Rating: 2
Defiantly a significant step in the right direction. The TDI Diesel technology has looked impressive since VW introduced it with the Golf Mk3. And this technology looks like a strong indicator of things to come. Imagine a family car with 100+ MPG figures.

At the very least it's an impressive stop-gap while we transition to something greener and more sustainable.

Cars with big supercharged V8's might be fun, but we have been using vast amounts of fossil fuels for the last century. It's probably time for a change.

RE: Efficiency ratings...
By Tabinium on 1/26/2011 12:55:42 PM , Rating: 2
IMO, cars like that should have 2 ratings, one in miles/Kwh, for when its only using the battery and one in MPG, measured after the engine starts.

AGREED! These "combined", "effective" and "average" fuel economy numbers that manufacturers spit out mean nothing.

Give us miles/kWh and miles/gallon and let us do the math!

An amazing concept: How to interpret it for YOU
By Emma on 1/25/2011 6:07:55 PM , Rating: 3
According to the VW press release
it goes 22 miles on electrics alone, and if you were to empty the tank, you'd get an avergage of 130mpg. So if you do long drives, that's what you can expect. If you drive mostly short trips, you can expect to hardly use any diesel at all.

Either way, it is a very interesting development of the L1. The whole drivetrain is a masterpiece:

The E-motor supports the TDI in acceleration (boosting), but as described it can also power the XL1 prototype on its own for a distance of up to 35 km. In this mode, the TDI is decoupled from the drivetrain by disengaging a clutch, and it is shut down. Meanwhile, the clutch on the gearbox side remains closed, so the DSG is fully engaged with the electric motor. Important: The driver can choose to drive the XL1 in pure electric mode (provided that the battery is sufficiently charged). As soon as the electric mode button on the instrument panel is pressed, the car is propelled exclusively by electrical power.

The use of CFRP, ceramic brakes, magnesium, polycarbonate combined with ABS and ESP means this is a very safe vehicle.

By Philippine Mango on 1/25/2011 8:43:47 PM , Rating: 2
130mpg isn't that special if you consider that the Aptera 2h is suppose to get the same fuel economy but on gasoline instead.

By Solandri on 1/26/2011 12:32:44 AM , Rating: 4
130 mpg is even less impressive if you compare fuel consumption instead of mileage. Say you have a 50 mile round trip daily commute. How many gallons per day would you burn in the following vehicles?

15 MPG SUV = 3.33 gallons
25 MPG sedan = 2 gallons
50 MPG Prius = 1 gallon
130 MPG VW = 0.38 gallons

So switching from a sedan to a Prius ("only" a 25 MPG improvement) saves you 1 gallon per day. But switching from the Prius to the VW (a "whopping" 80 MPG improvement) only saves you 0.62 gallons per day.

Or to think of it another way, if you drive an SUV now and are considering switching to a Prius or this VW, the difference in fuel savings is only 2.33 vs. 2.95 gallons per day. Only a 27% difference, even though the difference in MPG makes it seem like a 260% difference. Using MPG exaggerates the actual savings you get from high mileage vehicles, and auto manufacturer marketers and environmental groups are having a field day exploiting it to make us want to buy stuff which really doesn't help us that much.

The rest of the world measures fuel economy in liters per 100 km for this reason (it's the mathematical equivalent of 1/MPG). Only the U.S. relies primarily on mileage. Mileage is great if you're given a fuel budget and need to try to figure out how far you can go with it. e.g. You're given 10 gallons a week and need to stretch it as far as you can.

But most people don't drive like that. They drive a fixed number of miles per week, and are only concerned with how much fuel it will take to do that. For that type of driving, fuel consumption, or 1/MPG is the figure you want to be comparing.

By mmcdonalataocdotgov on 1/26/2011 8:03:56 AM , Rating: 2
21 MPG is the average mileage for a sedan in the US.

RE: An amazing concept: How to interpret it for YOU
By Wererat on 1/26/2011 8:30:28 AM , Rating: 2
Another way to interpret those figures is based on $3.10/gal gas and monthly (20 days/month) work-only commute costs:

SUV: $206.46
Sedan: $124.00
Prius: $62.00
1l VW: $23.56

"only" 2 gallons per day adds up, and these figures don't include any other driving.

RE: An amazing concept: How to interpret it for YOU
By Parhel on 1/26/2011 9:37:00 AM , Rating: 2
Diesel brings the the VW up to $26.22. And, that number assumes you started with a fully charged battery and then drove until the tank was empty. Electricity isn't free, so I'm not sure there's much if any savings there compared to the Prius.

RE: An amazing concept: How to interpret it for YOU
By bug77 on 1/26/2011 10:04:01 AM , Rating: 2
There's also the initial cost problem.

If I pay 25k toady for a car that needs zero fuel and you pay 20k for a regular car and 1k/year for fuel, after 5 years you still get the better deal.
I know, I've simplified the problem, but you get the idea.

By Wererat on 1/26/2011 4:18:43 PM , Rating: 2
Agreed on both counts; the $/gallon should use diesel fuel costs (currently $2.99 vs. $3.09 gasoline where I am, but this varies), and the per-month savings needs to be weighed against the initial cost and length of ownership. That's true whether you're buying a car or a water heater.

By Just Tom on 1/26/2011 10:20:41 AM , Rating: 2
Great post but it is not difficult to translate MpG to how much gas you will use is really easy. If I get 20 MpG and drive 350 miles per week I simply divide 350/20. How difficult is that?

By Paj on 1/26/2011 7:48:46 AM , Rating: 2
I thought exceeeding 50mpg was IMPOSSIBLE

RE: object
By silverblue on 1/26/2011 8:17:10 AM , Rating: 2
Nah. There are petrol cars out there that can manage more than 50mpg (US) average such as Fiat 500s using the 0.9l TwinAir engine. Diesels with larger capacity engines can easily achieve the same thing.

My diesel car achieves an average of 56.5mpg imperial (47mpg US) with a rather untuned 2 litre engine. With tuning, it'll get the 50mpg with little effort AND perform better, though I'm understandably wary of tuning.

RE: object
By Paj on 1/26/2011 10:00:09 AM , Rating: 2
Thats cool. Good to see progress is being made.

I was just being my cynical self, and referrring to a previous article where US automakers said it wasnt possible.

RE: object
By Just Tom on 1/26/2011 10:22:51 AM , Rating: 2
The question is not whether it is possible the question is whether anyone will buy them. Small cars are profit killers for American manufacturers and will be as long as legacy costs are so high.

RE: object
By silverblue on 1/27/2011 6:57:57 AM , Rating: 2
With the exception of cars like the Bluemotion VWs, I suppose, as these will carry a bit of a premium as a result of their better fuel consumption.

By chunkymonster on 1/26/2011 9:22:33 AM , Rating: 2
This is an idea who's time has come! Kudos to Volkswagen!

Currently driving a Jetta TDI and getting over 40mpg, it is not a stretch for me to imagine a diesel electric hybrid getting 200+mpg. Even if the production version of a diesel electric hybrid "only" got 100+mpg it is still a huge win!

In my opinion, a diesel electric hybrid is one of the few ways to end the need for petroleum based fuel. Using bio-diesel truly has the potential to reduce, if not eventually eliminate, the need for diesel distilled from petroleum.

This is an excellent idea and I would hope that American car makers recognize the potential for diesel electric hybrids and begin their own diesel electric hybrid car programs.

By Just Tom on 1/26/2011 12:13:51 PM , Rating: 2
There is no way bio-diesel will replace the need for petroleum based diesel.

By Suntan on 1/26/2011 12:47:53 PM , Rating: 2
I don’t want to rain on anyone’s parades, but at the same time, let’s look at some of the practical aspects of this situation without getting too bogged down in the technical minutia.

Namely, let’s have a look at this idea that 1) Diesels get good mileage, 2) hybrids get good mileage put 1+2 together and you get great mileage!

First off, let’s look at the traditional car with a spark ignition engine. One of the drawbacks of this design is that the spark engine makes relatively weak torque/power at low RPMs. This requires two things a an engine that is sufficiently large so that it can actually get the car moving, and a sufficiently complex transmission to allow the engine to stay out of the low RPM/low torque operating area as much as possible. This “overly large” engine then is normally working at a fraction of its optimum efficiency for the remainder of its working cycle once the car has finished accelerating up to speed and the engine is running at a high RPM where it normally develops much more torque. As such, most of the time you end up with much more engine than you need (and much more transmission) just to accommodate the periods where the vehicle must accelerate from a stand still. On their own, they tend to be a little cheaper than diesels (without needing the relatively expensive emissions components of a diesel) and obviously benefit (in the States anyway) from a much better public image.

Now let’s look at the diesel equipped car. Diesel engines tend to make substantially more torque at much lower RPMs than a spark engine of the same category, while the torque tends to peter out quickly as RPMs raise. This allows for a smaller engine that can be more effective at speed, but still allows a person to accelerate away from a standstill. They do tend to be more “efficient” overall than a sparker, so it isn’t just a matter of the smaller the engine the better the MPGs, but the main point is that for a given vehicle, a diesel can roughly do the job with less size, and less fuel. However, they tend to cost more for a couple of technical reasons (higher combustion pressures require more steel/aluminum, etc.) but mainly because they require expensive after treatment of their exhaust gases to meet the strict emissions requirements in the Sates (these requirements are much more lax in Europe, and as such European diesels do not get burdened with as much cost for emissions treatment.) Further, the transmission can be simpler (although it needs to have more substantial gearing in the first stage) in that it never really has to cope with the loads produced by running at higher RPMS, but it still needs a fair amount of gear ratios to keep the diesel engine running in its narrow powerband. All that said, as the TDI offerings clearly show, a carmaker can successfully make a small market out of charging more for a car that gets the better mileage when a more expensive diesel is used.

In comes the conventional hybrid (with spark engines.) The current hybrids are a complimentary design with an electric motor and a spark engine. As discussed above, the spark engine is weak at low RPM. As all these hybrid articles always point out, the electric motor works best at the low RPMs, petering out as RPMs rise. Put the two together and you can have a smaller, less thirsty engine for most operation, with the motor helping it get going at low RPMs. You also get a more uniform torque output (from both the engine and motor combined) across a broader RPM range. That allows you to have a simpler/cheaper transmission that doesn’t need a vast amount of gears to keep the drive train happy as the vehicle moves from standstill to normal speed. So even though you have to eat the cost of an added motor and battery, you recoup a bit of that in having a smaller engine and simpler transmission. That said, they still tend to cost a fair deal more than a comparable vehicle with just a spark engine, but they get more mileage while doing it.

Now let’s look at the diesel hybrid. As discussed, the diesel likes to make a lot of torque down in low RPMs… The electric motor also likes to make a lot of torque down low in the RPMs… Neither of them like to operate up in the high RPM range. So now you have a drive train that makes stump-pulling torque down in low RPMs, but quickly runs out of juice as RPMs rise. This means you still need a transmission with many gears, but now they also have to cope with substantial torque input, which does add cost. So now you have a diesel engine, which tends to cost more than its spark cousin, an extra motor/battery and a more expensive/high gear transmission that can handle prodigious torque. Those three components add up to a lot of cost that is hard to balance out, even with high MPG numbers. People would likely have a severe case of sticker shock if they saw the price of a production hybrid diesel and how much more of a premium it was over a hybrid with a traditional sparker (and that’s long after the CF skins and ceramic brakes were cut in the journey from concept to production.)

There’s a reason VW keeps making “prototype” and “concept” vehicles centered around the hybrid diesel. But I’d wager it has much less to do with looking forward to production, and a lot more to do with trying to get hybrid crazy Americans to start looking at their traditional TDI lineup.


By drewsup on 1/26/2011 2:46:00 PM , Rating: 2
There is one flaw in your argument, this is a 2 cylinder tdi, the cost and weight issues of a 4 cylinder do not apply.

By Suntan on 1/26/2011 4:44:28 PM , Rating: 2
This is a one-off prototype with carbon fiber panels and all the regular car show jazz. Don’t look to far into the specifics of this concept car and try to extrapolate it to what a real world diesel hybrid would look like.

In any case, the above comments hold for any model of car, 2 cyl vs 4 cyl doesn’t change the fact that hybrid spark ignition cars have a much more complimentary layout than hybrid diesel cars.


Wonder how well...
By theArchMichael on 1/25/11, Rating: 0
RE: Wonder how well...
By Amiga500 on 1/25/2011 5:59:41 PM , Rating: 2

As long as there is enough room in the wheel well, it won't present a problem.

Covered rear wheel arches were not unknown in the past.

The Citroen DS for example.

RE: Wonder how well...
By Souka on 1/25/2011 7:16:00 PM , Rating: 2
More recent, Honda insight (1st gen)

RE: Wonder how well...
By mmcdonalataocdotgov on 1/26/2011 8:09:38 AM , Rating: 2
My 1968 Buick Skylark.

RE: Wonder how well...
By kattanna on 1/26/2011 11:37:41 AM , Rating: 2
Covered rear wheel arches were not unknown in the past

while true, big difference here. in cars past you still had basic access to the lug nuts on the tires. according to the pic above on this vehicle, you dont. which would be an issue for me.

don't care for naming
By Souka on 1/25/2011 7:18:16 PM , Rating: 2
When I read the article title I picked up on "Formula" and "1" which led me to believe performance electric/disel.

The words "formula" and "1" should never be in a car's title unless it's the real deal... "Formula 1"


By silverblue on 1/26/2011 8:19:49 AM , Rating: 2
The MPG value in the title is likely Imperial, which translates as 216mpg US. Still impressive.

By Richard875yh5 on 1/26/2011 9:56:38 AM , Rating: 2
Just another story to grab headlines, unfortunately. Except this story is exaggerated even more than the Volt 220 mpg.

By espaghetti on 1/26/2011 2:10:37 PM , Rating: 2
Volkswagen used the show to unveil the latest in its line of vehicles aimed at extracting the ultimate mileage out of a single gallon of gasoline.

Strange place to unveil a new Diesel-Electric Hybrid car imo.

"Well, we didn't have anyone in line that got shot waiting for our system." -- Nintendo of America Vice President Perrin Kaplan
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