128-mpg Kubota Diesel-Powered Sports Car

[B Calm]

Centurion

128-mpg Diesel-Powered Sports Car
Centurion combines diesel-engine efficiency with the effects of high engine loading, reduced vehicle weight, and good aerodynamics to push fuel economy well past the 100-mpg mark. And one of the most straightforward ways to reduce emissions is to reduce the amount of fuel consumed. In reality, many other variables affect engine-out emissions, but assuming equal technology, reduced fuel consumption loosely translates into reduced emissions.

The technology used to produce Centurion's high fuel economy is very fundamental. An internal combustion engine runs most efficiently when it is operating at 60% to 90% of maximum output. When an engine is throttled, fuel economy plummets. Automobiles operate most of the time with the engine throttled to 5% or less of full power, such as when cruising at low speeds in urban traffic. Even on the highway, the average family sedan can cruise at 55 mph on a little as 8 to 10 hp, which is only a fraction of the power capability of the engine. An engine throttled into fractional power regions can use double or triple the fuel per horsepower output.

Centurion first reduces road load by keeping weight and aerodynamic drag to a minimum with its sleek shape and low, 1,200-pound curb weight. Minimum installed power, tall gearing, and a transmission with high ratio selectivity combine to allow for high engine loading. With its 17-hp, 3-cylinder Kubota diesel engine coupled to the 5-speed transmission with overdrive in each gear, the engine can be loaded into its region of minimum brake specific fuel consumption at just about any speed. These are the primary factors responsible for Centurion's fuel economy at cruise. Stop-and-start fuel economy benefits from low weight, which translates into less energy lost to inertia in urban traffic. Reduced fuel consumption at idle and during braking results from the small-displacement engine.

At 35 mph, Centurion delivers at 128 mpg. At 45-mph, fuel economy is 103 mpg, and at 55 mph it drops to 85 mpg. The poorest fuel economy recorded was 64 mpg, which occurred in downtown urban traffic. Turbocharging the engine would increase maximum power and performance, and improve fuel economy as well. As originally equipped, Centurion has a maximum speed of 65 mph.

Centurion is one of our most expensive cars to build, primarily because of the cost of the diesel engine - new, about $2,500. Its Triumph Spitfire chassis, however, is relatively inexpensive if you purchase it from a wrecking yard or private party. The remainder of the cost is in fiberglass, paint, fixtures, and accessories. Total cost will be in the order of $5,000 - $7,000, depending on how the car is detailed. Using the original Spitfire engine, instead of the Kubota diesel, could save about 50% on costs. If you would like more information on building Centurion's body, click on One-Off Construction Using FRP/Urethane Foam Composite.

Centurion was built in 1981 and featured on the cover of Mechanix Illustrated magazine in February 1982. It appeared as a background vehicle in the movie Total recall.



Specifications

Length: 156 inch
Width: 62-1/2 inch
Height: 44 inch
Wheelbase: 83 inch
Front Tread: 51 inch
Rear Tread: 50 inch
Brakes: Disc front/Drum rear
Curb Weight: 1200 lbs
Ground Clearance: 6 inch
Turning Circle: 24 feet
Fuel Capacity: 10 US gallon
Seating: Two, side-by-side
Power train: Kubota #D 750 BB Diesel
Power: 17 hp @3000 rpm
Displacement: 46.5 cubic inches
Bore: 2.68 inches
Stroke: 2.76 inches Compression Ratio: 22:1
Number of Cylinders: 3 in-line
Type: Vertical water-cooled 4-cycle
Weight: 181 lbs
Transmission: 4-speed, manual-shift, full syncro with overdrive
Final Drive Ratio: 3.98:1
Body: Foam/Fiberglass sandwich
Fuel Consumption:
128 mpg @ 35 mph
103 mpg @ 45 mph
85 mpg @ 55 mph
65 mpg in city traffic
Top Speed: 65 mph (in overdrive)
Special lubricants: Transmission filled to factory specs with Torco MTF fluid. Final drive filled to factory specs with Torco Hypoid 90 gear lube.

http://www.rqriley.com/cent.html

[burrowowl]

1. K&R

Very interesting!

[B Calm]

2. On the same website, The XR-3 Hybrid gets 225 mpg on combined diesel and

electric power and performance like a conventional automobile.

http://www.rqriley.com/xr3.htm

[mitchtv]

3. I loved my Kubota B210

dependable

[B Calm]

5. Today I bought the BX2230 with a front loader, rear grader blade and

a 60 inch mower deck. Suppose to deliver it tomorrow, I can't wait!

[mitchtv]

6. Mine was good as new the day I sold it

after ten years

[Mugu]

8. Have had mine 14 years and have only replaced blades and one set of U-joints.

[B Calm]

9. I was all set to get John Deere utility tractor. After checking out Kubota

I was sold. I couldn't pass up on a good deal on a two year old tractor. I was curious why the original owner was selling it. When I found out it was because he was getting divorced, it made sense. I hope my Kubota holds up like yours did. My tractor will get a lot of work, mowing, snow removal, grading, etc etc and taking care of my 12 acre estate.

[lumberjack_jeff]

16. I have a New Holland 1720. Great little tractor.

Little diesels are great. I think my lawnmower burns more fuel.

[Mugu]

12. With 60" mower deck I can get almost 9 MPH.

[Clear Blue Sky]

4. Wish diesel was cheaper and we had more diesel vehicle options in the US.

[Canuckistanian]

7. Looks like a "car of the future" - designed in the 70's

Still, there's some smart thinking there about how cars are ACTUALLY driven.

[Selatius]

10. It looks like a cousin of the DeLorean from Back to the Future.

[alfredo]

21. Looks like a Bricklin.

[CRF450]

11. Sorry but I cant even consider that a "sports car".

A sports car (for me atleast) is a low sitting vehicle with gobs of power that nails you into the seat under acceleration. And their are times, that I'd like to go more than 120mph on an empty highway or race track.

I like my current sports car.

[B Calm]

14. Did you check out XR 3 Hybrid on the website? It's pretty cool, for

a 3 wheeler.

[EOTE]

15. Seriously...

It certainly seems like an interesting example of technology. However, I'd be hard pressed to see this thing have sporting intentions. Granted, 1200 lbs is feather light, but with 17 hp (I assume a good deal more torque, but I didn't see that figure), that thing has to haul more than 70 lbs per horsepower! My far heavier GTi (2800 lbs) only has to lug about 11 lbs per horse, and I still wouldn't consider it to accelerate like a sports car.

[CRF450]

17. I'd like to see the torq numbers too.

And yeah, 1200lbs is damn light weight for a car. Mine weighs around 3500lbs, but with 350hp it'll still do 0-60 in 5 seconds. Is your car a Lancer, or something like that? Whats the your getting? My Trans Am averages around 22-23mpg, and I have reached 31mpg on the interstate. Pretty good for a high powered v8 huh? The Corvettes now have over 400hp, yet they get the same fuel milage I'm getting.

[Selatius]

18. According to this, you can double horsepower and double fuel efficiency and cut emissions

You just have to replace the tranny and engine block in your firebird with a V-8 diesel, probably a Duramax, since Pontiac is a division of GM. If it's a Duramax, you need a 5-speed Allison transmission that goes with it. That alone could get you up to 40% more fuel efficiency because diesel engines are inherently more fuel efficient. Then you cut the diesel with either hydrogen gas or methane gas in the combustion chamber. The gas itself displaces up to half the diesel injected, effectively doubling fuel efficiency on top of the fuel efficiency gains from simply switching to a diesel block.

Your car could be both green and mean. You can read the full article below. It's quite fascinating.

"Johnathan Goodwin can get 100 mpg out of a Lincoln Continental, cut emissions by 80%, and double the horsepower. Does the car business have the guts to follow him?"

http://www.fastcompany.com/magazine/120/motorhead-messiah.html?page=0%2C2

[CRF450]

19. Thats gonna be a crap load of work though.

And something that I do not want to undertake. I highly doubt the stock computer would work with a Duramax, and if thats removed, the guage cluster is not going work, and many other electrical accessories wont either. If ethonal can be a viable alternative, I can easily have the car converted for it. All thats needed is a good raise in the compression ratio, swapping the fuel pump and other fuel-injection parts, and retuning the computer and spark timing.

[AdHocSolver]

13. Hybrid-electric technology is the BEST way to reduce oil consumption and reduce pollution.

Moreover, hybrid-electric vehicles can be developed and mass produced with existing technology.

The maintenance costs for electric vehicles is far less than for internal combustion (IC) engines. No mufflers, no complex transmission is needed, no complex cooling system, no complex fuel system, and no regular oil changes.

Electric motors have a mere handful of moving parts compared to the hundreds of parts in an internal combustion engine. This means less parts to go bad and have to be replaced. This also means less frictional losses.

A major problem with internal combustion engines is the low torque they produce especially at low RPM. This necessitates a complex transmission to convert high RPM to the higher torque needed to get the vehicle moving from being stopped. This requires increasing the RPM (using more fuel) when starting out from being stopped ("stepping on the gas"). To get proper operation, the IC engine requires being maintained at a relatively high operating temperature. Energy, and fuel, is wasted to keep up this temperature, AND removing the excess heat constantly being generated by the engine constantly running (the cooling system). The IC engine is a highly inefficient, wasteful, and expensive means of propulsion.

Electric motors have few moving parts so they are low friction devices compared to IC motors. When the vehicle is not moving, such as at a stop light, the electric motor can be turned off. Since it is off, it draws no power, uses no fuel, and produces no heat.

Electric motors can produce high torque even at low RPM so that no complicated energy using, heat producing transmission is needed.

Maintenance costs for electric vehicles would be a fraction of the cost needed to maintain an IC engine vehicle.

Electric motors do need a source of electricity. Electric vehicles use batteries to store the electricity. However, the electricity must come from plugging the vehicle into an electric power outlet or having an on-board generator or alternator to charge the battery.

The most optimal solution is to use both techniques. Have plug-in capability and have an on-board alternator to continually charge the battery. A small, low horsepower, fuel operated engine could be hooked up to drive the alternator and NOT to drive the wheels. This means it could be designed to run on any kind of fuel to run at one speed for highest fuel efficiency and least polluting effects.

Such a combination should be able to achieve fuel efficiency figures of 100 MPG or more. The expertise derived from the manufacture of diesel-electric train engines could be used to manufacture trucks with comparable fuel efficiencies.

The knowledge to implement this technology exists today. It is doable and affordable. The oil companies and their "cousins" over in the auto industry don't want to do this because it will reduce maintenance costs and oil consumption, and therefore corporate profits. They prefer to put off implementation by promising pie-in-the-sky promises of "magical" hydrogen fuel cell vehicles in 2015, or "whenever". That is pure hype and merely stalling tactics. Moreover, the planet cannot sustain the continual pollution with its bad effects on living creatures.

What about performance? The Tesla electric car can go from zero to 60 MPH in 4 seconds. High torque output, fewer moving parts, and less friction make for high performance capabilities.

[flvegan]

20. 17 horsepower? Good luck with that.

Maybe with a good nitrous hookup, one could turn left without an oncoming moped obliterating your ride.