2013 Volkswagen XL1: The Whole Story of a Real-World 261-MPG Car

That looks like the GM impact!!

Even if it only gets 100 mpg, that is still very impressive and I like a two seater. Not every American like driving tanks. An American engineer, I believe this magazine carried the article, developed a converter that allows you to get 763 mpg. He had it on his Nissan. I believe he said that the converter would cost over 2,200 dollars until production. Why didn't any auto manufacturer pick up on that converter?

@Warren - I'm with you! Just boggles the mind how efficient a narrow, two-wheeled machine can be. And Fast? Forget about it!

As for the name.. yeah, more than a bit confusing. I say stick with "Tracer" and call it a day! Maybe G for gas and E for electric if they really need both. But once folks get to experience the E, the G won't be made any longer. Who wants to mess with the clutch and gears and pulling into a gas station?

@JJJ - agreed! One of the amazing things of cycling, motorcycling, driving a Tango, driving a Tracer, etc... is the astonishing visibility afforded by having either no windows, or having them right next to the driver on all sides. There are many benefits to tandem seating that shouldn't be ignored just because we're so used to side-by-side seating in our automobiles.

Hi JJJ
Tandem is the way to go for reduced frontal area, and can lead to lower Cd, compounding the effect. In a three wheeler, there can be crush space on both sides, improving crash worthiness. But, as I say in my website, the obvious advantage is that your girlfriend rides with her legs wrapped around you.

Hi Ex-Ev1,
>>?First the TDI, now this.<<
You write as if this is a bad thing. If the LX1 can get 100-110 MPG on gas, then it will get 10 miles per kilowatt hour on electricity. (Making it, ostensibly, as efficienct as my avatar car, which is less than half the mass, and which uses 90% efficient, permanent magnet motors and a 98% efficient controller. One could wonder where their efficiency is coming from.). That electrical consumption makes the LX1 2.5 times as efficient as the LEAF and Volt, and twice as efficient as the EV1 was.

The TDI is the most efficient ICE used in any car (42% at peak) and can be run on biodiesel, unlike a Prius or 99% of the cars on the road in the US. The European Polo offers 70 MPG in the Euro test, so will be about 60 MPG here. VW has its own pure electric on the way (with Martin Eberhardt, the guy who designed your Tesla's batteries) working with them on battery design.

There are plenty of Johnny-come-latelies in the efficienct car and EV biz. VW is not one of those.

@Ken Fry - I sure wish there was a way to communicate privately on these forums! Hate to do this... can you contact me off-list, please? darell*at*evnut . com.

>> Your girlfriend/wife is used to seat on your side, would she enjoy being in your back? <<
Can't let this one go!
1. Just because we might be "used to" something sure doesn't mean we should continue it! We were "used to" keeping the races separated. We were "used to" not letting women vote. We are "used to" burning gasoline. Fear the change!
2. And this is my favorite - no, my wife is NOT used to being seated at my side. I don't drive in a car much. She's used to being on my tandem bicycle: http://darelldd.smugmug.com/Bicycle/2008-Rides/2008-Tour-De-Cure-1/08050...

And as we all know, I'm rarely the "target audience" for mainstream product.

@ ex-EV1,
The TDI has been around for a long time, and has done its a share in saving fuel.

Regarding average efficiency for the TDI, I think your 20% figure is very close, and probably a little generous. The actual efficiency depends upon the installation, with higher efficiency in heavier cars, and of course on driving patterns. I mentioned the peak figure because it is a good yardstick for relative efficiency: the engines in a Prius, a Ferrari, a VW and a Honda Civic are all 5% efficient part of the time, 10% efficient part of the time, etc. Peak efficiency does not tell you everything about an engine, but can help separate the highly-efficient ones (like the TDI at 42% and the Prius at 38%) from the lower efficiency ones (like general aviation engines at 27% and lawnmower engines at 25%.) Peak efficiency is shorthand for a description of specific fuel consumption, which requires a fairly complicated graph to communicate -- and even that graph does nothing to describe operating efficiency as installed in a vehicle.

I've run hot and cold re VW over the years, but think their EVs could do well. One of my favorite VW's was built by a friend of a friend in engineering school, decades ago. It was a dragster with a 40 hp engine driving a hydraulic pump which charged an accumulator so big that it effectively was the chassis/body. By the time the car was at the starting line, the accumulator was charged and this "40 hp" VW would smoke all four tires via hydraulic motors at each wheel.

My avatar car is now in limited production. I don't want to hijack this thread with a sales pitch, so will email you off line.

Hi Laurent,
>> most couples enjoy to sit side by side <<
I had a friend who had an old Triumph motorcycle, which vibrated incessantly. His girlfriend loved riding behind him. Decorum prevents my giving a full description here, but suffice it to say that she almost fell off the back as a result of a certain peak experience induced by the vibration.

>> Like all diesels, its efficiency is at its best at idle or at lower RPM with the considerable advantage over an Atkinson gasoline engine of making much more torque. <<
Actually, at idle, efficiency falls to 0%: if the engine is idling, it is doing no work. Peak efficiency (of 200 g/KwH = 42%) in the TDI is reached in a range from 1400 rpm to 2100 rpm. A series hybrid could be easily constructed so that the engine operates only in this range, or not at all. The Prius could be slightly more efficient with a diesel, measured in MPG terms (because the peak efficiencies are 42% vs 38%, and the Prius system tends to keep the engine well-loaded most of the time). But in terms of resource usage (and in the US, fuel cost) there is no advantage, because the energy content of diesel fuel is higher: in terms of BTU per gallon, diesel is a more valuable fuel.

Of course, biodiesel could be used in a TDI-engined Prius, which could be a large environmental advantage, depending upon how the biodiesel is made.

Here is a good discussion of TDI engine efficiency: http://forums.tdiclub.com/showthread.php?t=208125
Post #14, in particular, shows that with the TDI, it is almost always better to use the highest gear (lowest rpm) possible, supporting your point that 2000 rpm would be a good rpm limit. Also notable is that at powers between 20 and 70 hp, consumption of 210g/kWh or better can be obtained. That is a very broad range of high efficiency operation.

There are large gasoline engines that operate at about 10% efficiency at 20 hp. The TDI engine, at that hp, is about 4 times as efficient. The Lamborghini Murceliago gets a stunning 8 mpg in the city, despite being only 20% heavier than a Jetta TDI.