8128 miles Per (US) Gallon

idletask writes: "Yes, you read well. This is the new record established this year in the Shell International Mileage Marathon (NOTE: English link, their figures are calculated using UK gallons), held this year on June 1st and 2nd on the Circuit of Nogaro, by a team from Université Paul Sabatier in Toulouse, France. This yearly contest, sponsored by Shell since 1977, consists in travelling the longest distance with only one liter of gas (the record is therefore actually 3494km with 1 liter), at a minimum pace of 25kph (~15mph). Full results of the contest can be found in a PDF file. The only US team who participated this year scored 69th, with 1136mpg (483km with 1l)."

Comments

More info

[DeadSea]

Junkyard wars had an episode in which the contestants had to build super fuel efficient vehicles. They showed some clips of these actual races. The basic premise is that you get very light, very aerodynamic, much lubrication, and thin tires with a large diameter to reduce rolling resistance. Most of the entrants burn their fuel in stages and build up speed and then cut the motor and coast because engines need some amount of fuel flow to keep running and their efficiency goes to where flow would be below this minimum.

The most fuel efficient car you can get in the US is still the Hybrid Electtric Honda Insight. I have about 63 mpg average over the two years that I've had mine.

Re:More info

[JabberWokky]

The batteries are charged and dumped in there... look in the background and you'll often see a pile of batteries that they pulled out of the junkyard and were dead. The engines in that corner of the junkyard that they scavenge from are the cream of the entire junkyard - basically, the few working engines, motors and other parts from a several square kilometer junkyard. They are also all newly dumped, so they haven't rusted.

Is it real junk from a real junkyard? Yes. Do they cream off the very top and concentrate it down in the corner they film in? Yes. Do they seed it with items from the junkyard that might be useful for that week's challange as recommended by the experts (sheets of material for hanggliders or hovercraft, screws/propellers for boats)? Yes. Is it still junk from the rest of the junkyard? Yes... unless it would be a safety hazard or just not found in a junkyard. In those few cases (high class solid rocket engines or parts for a steam engine) they are seeded with tested components.

That's a darn few cases, so most episodes feature real junk - prescreened junk, but real junk from the musch larger yard visible beyond the edges of the set. I've known a few people who went into a junkyard and, a few weeks or months later, had a working vehicle of some sort - dune buggy to functional (and butt-ugly) car. The parts are there, they just are a pita to find. The corner they film in is full of *just* the useful and working bits from a huge junkyard. Motorcycles with smashed front ends, vans with rusted out frames, etc.

--
Evan

Description is misleading

[GregWebb]

Unless they've recently changed the rules, they most definitely do _NOT_ give them their litre of fuel and tell them to keep going until they get bored. 8000 MPG, average speed of 20 MPH (say), that's over 2 weeks of continuous driving.

Last I heard they took the cars, ran them over an agreed course of a few miles maximum, excluded those who ran too slowly then measured the amount of fuel left in all the cars VERY CAREFULLY :-) and computed the MPG from that.

Re:Description is misleading

[Merlin42]

The rules state that the fuel tank can be no more than 750ml. In fact the maximum valume the rules allow depends on the type of system with some having a maximum of 50ml!

Re:Lack of information

[Christopher Thomas]

None of the links in the story provide any useful information at all, as far as I can see. The first is for a "Mileage marathon society" which doesn't appear to have any information about a particular recent contest. The second is for the location at which the event was held; the third links to a blank page inside Shell with some plugin that doesn't work in my Mozilla. Searching Shell for "Mileage Marathon" produces lots of results in other languages and from 1998-99, but nothing topical.

A few links in, there's more information. Here are the contest rules:

http://www.shef.ac.uk/~mms/rules.html

They have to do 6 laps of a 1.64 mile course with a minimum _average_ speed of 15 miles per hour. The vehicle with the lowest fuel consumption wins.

The vehicles have people in them, which puts a lower limit on their size. Engine technology can be anything that qualifies as a heat engine and runs on unleaded gasoline.

Supermileage

[Tablespork]

I participated in the Minnesota Technology Education Association's Supermileage Challenge in May. It was basically the same thing except it was just a bunch of high school teams. It really is a great competition, I learned a lot and had tons of fun.
My team ended up with a top mileage of 305 mpg, this was for the stock class. Fairly good considering we had limited time, budget, and experience.
The way our competition worked is this: Each team is given a fuel bottle and it is weighed before the start. You then go around 2 laps (of the 3 mile track at Brainerd International Raceway) for a total of 6 miles. They then weigh your fuel bottle again to determine how much gas is used (making sure there are no air bubbles in the fuel line). This ends up a pretty accurate way of determining gas mileage. The weight of the gas really shouldn't matter that much, since more weight would mean you carry your momentum longer. You have to complete 6 runs and they take the average of that.
Now since we are high school students, our main goal was to build a working car. You then focus on aerodynamics, good bearings so it rolls well, wheel alignment, steering, and driving practice. Getting practice is key. Not only to determine what will break, but also to get good at controlling your burns. Short burns at high rpm's get you up to speed(roughly 30, which was the max), at which point you cut the engine and coast down to around 10(you have to maintain an average of 15). By the end of the 2 day competition, you saw drivers getting very good at rolling to a stop inches over the finish line.
It was a really fun competition, we saw some very cool cars with everything from carbon fiber bodies, to computer sensors and lcd displays mounted on the steering wheel, and you could download all the data to a computer for analysis. Sweet stuff.

Re:Not entirely correct.

[tbmaddux]

Actually the Golf/Jetta TDIs don't even approach the top 10 of most fuel-efficient cars (by EPA combined mileage rating) ever sold in the U.S, going back as far as 1986 (when the numbers changed a bit). If you can't top 50 mpg, you can't play with the big boys:

1. 2000-02 Honda Insight 5spd (65 mpg)
2. 1986-87 Chevy Sprint Er (57 mpg)
3. 1988 Chevy Sprint Metro (56 mpg)
4. 2001-02 Honda Insight CVT (56 mpg)
5. 1990-94 Geo Metro XFI (55 mpg)
6. 1986-87 Honda Civic Coupe HF (54 mpg)
7. 1988-89 Honda Civic CRX HF (52 mpg)
8. 1992-95 Honda Civic HB VX (51 mpg)
9. 1990-91 Honda Civic CRX HF (50 mpg)
10. 1985 Chevy Sprint (50 mpg)
11. 1985 Suzuki Sa310 (50 mpg)
12. 2000- Toyota Prius (48 mpg)
13. 2003 Honda Civic Hybrid (48 mpg)

I think you can make a case for those 4 Civic models being essentially the same car. There may be some other older cars that I missed, but they'd have to be older than 1986. As far as overall "greenness," the batteries in the Insight are nickel-metal-hydride, not nickel-cadmium, as someone else pointed out, and the diesels are rated with a score of 1 out of 10 on emissions. The CVT Insight gets an 8 or a 10, the manual Insight gets a 5 or a 6, and the Prius gets a 7 or a 10. Until biodiesel is widely available, the VW diesels definitely aren't a good "green" choice, and we may have fuel cells before biodiesel...

Re:Measurements

[AndrewRUK]

483km/litre = 1.22*10^-8 lightyear/hogshead

Yes but...

[idletask]

EPA ratings, much like ISO ratings, reflect close-to-perfect usage conditions (flat roads, constant speed etc). They are far from reflecting everyday use where you have to slow down/accelerate/etc constantly. And then again there are curves/uphills/etc. I doubt any of the cars you have listed actually score their listed mileages in everyday use. As a matter of fact, most reviews of the Prius (sold here in Europe, unlike the Insight) score it at 35-40mpg rather than the listed 48mpg EPA rating.

Which is where modern Diesel engines take a clear lead: accelerations don't require as much energy as gas engines require. The reason is that Diesel engines spot a much higher torque. Provided that you don't drive hard, you can be sure that VW's TDIs announced mileages WILL be what you actually consume. And if you drive hard, the mileage of a Diesel engine will decrease far less steadily than with a gas engine as well, always because of superior torque. The same goes on if you carry more passengers than yourself alone.

Just for information, I'm the (very) lucky owner of a BMW 330d (WARNING - UK gallons! Following figures are calculated using US gallons though). Cruising at 60mph, mileage is 41mpg, whether the road be flat or not. Cruising at 75mph, mileage "drops" to 35mpg - and this is not surprising if you consider that at both of these speeds, the engine provides its full torque of 288(!) lbft (~1800rpm at 60mph, ~2100rpm at 75mph), and full torque means best fuel efficiency. Not bad for an engine which spots 183hp and has a 3l displacement, eh? (and the car weighs 1.6 ton!)

Another example: a friend of mine owns a Skoda Fabia TDI 100 (a VW TDI, since Skoda is owned by VW - 100hp, 180 lbft torque, 1.9l displacement, 1 ton) (sorry, couldn't find an online review). We swapped cars on a WE just for fun and I wanted to see how well the TDI performed... 46mpg at 60mph and 39mpg at 75mph (yes, greater gap here, but unlike the BMW 3l engine, the TDI isn't on its max torque curve at 75mph).

And as an added bonus, both of these cars are enjoyable to drive. This is not so the case with, say, the Prius (which is available in EU, unlike the Insight). Again, thanks to the torque.

There are still two weak points with the Diesel engines, though, but these are being addressed. Technologies exist and will make inroads into the EU market in the next 3 years:

• town mileage is fatally higher right now. Solution: the starter-alternator (unfortunately, scarce documentation on this thing on the net - it's dubbed STARTS by Valeo, and Energen by Delphi), which provides stop features: engine is off when you're idle at, say, a traffic light, then starter-alternator restarts it nearly instantly (less than 100ms) when needed. Added bonus, it removes the alternator from the picture (and therefore removes a strap belt from engine design, therefore lowering friction and increasing efficiency) and allows for 110/220V electrical plugs to make it into cars! The first car equipped with this in EU will be the Citroën C4, programmed for late 2003;
• particles (which is why Diesel scores so poor at emissions rating right now - this is not because of greenhouse gas emissions, which is considerably lower with Diesel engines due to their greater efficiency). The solution already exists: the particle filter, which has first equipped the Peugeot 607 back in 2000 and now equips several models from the PSA group. This filter will be compulsory on all new Diesel engines by 2003, Jan 1st. Combine this with the requirements for petrol makers to reduce the quota of sulfur in Diesel fuel (which IS the cause for particles) by 2005.

Of course, ultimately, fuel cells will replace Diesel and gas engines altogether, but it will be a good 10+ years before it gets viable (both cost-wise and reliability-wise). Both of the technologies above exist today and are [already on/close to make inroads into] the consumer market. Also consider that car manufacturers, by 2005, will have to obey "depollution" norms in EU which basically require engines to have a global mileage equal or better than 45mpg. Whatever the technology employed.