Possible to make/mod a 200 MPG highway cruiser?
 

I would like to know if anyone thinks it is possible to make/modify a car to get 200 MPG on the highway.

Here is the specs:

1000 miles unrefueled range
65 MPH average speed

Other than those specs, sky is the limit.

I don't think any production car car get 200mpg @ 65mph without extreme mods. Areo to the max, carbon fiber everything, and a small engine might just do it.

something like a 80-90cc scooter could probably do it if it had an aero body built for the sole purpose of getting mileage. I don't think it would be fun to drive though being wedged into an aerodynamic body with no ventilation and no room to haul anything except yourself.

The hard part is the 200 mpg (you'd need only 5 gallons to go 1000 mi.).

The specs for the Aptera at 55 mph with a parallel hybrid diesel are 230 mpg. At 65 mph, you'd need about 1/3 more hp and would probably get less than 200 mpg. It's not mass-produced yet but you can put a deposit on one.

Do you think a geo metro 3 cylinder with maxed out aero mods would do it. I mean radical aero mods.

http://www.cosmocentral.com/post/200...0-mpg-Car.aspx

Take this and mod it even more and see what you come up with. I'm guessing the best way would be to either take a turbine engine and tune it way down or taking a really small diesel engine and working with that.

That link looks interesting, but the car designs don't look very aerodynamic. When I compare Basjoos's car with those, there are no wheel skirts, air dams, or tail cone.

Next question:

To get to 200 MPG highway, what is the most important aspect.

1) powerplant/engine/fuel
2) aerodynamics
3) hybrid design
4) transmission

you can't just get if with one of those, you can have the best powerplant in the world but if your driving the empire state building around your not gonna get 200mpg, hybrid I think is the least of our worries, because we can get by on a turbine or diesel. Tranny is third.

Since we're traveling at 65, Im gonna go with aero, followed by powerplant, then tranny, and if we're doing a hybrid, so be it.

Oh, and the link, you take that car, then aeromod it. BOOM, better mileage. or you could take that and the aptera and combine the aptera's aero with this one.

I see what your saying, combine the aptera with the powerplant in the link. Off topic a little bit, but I think the Aptera should be 2 wheels only with outriggers that come down at slow speed. How cool would that be.

Aerodynamics, transmission, then powerplant/engine/fuel in that order. You can solve backwards for parameters to figure what ya need (lmk if ya need info/pointers). Based on my offhand calcs, you're probably gonna need the smallest Metro to have a drag coefficient of ~.12-13 and the best LRR tires pumped up a bit. Then, in order for the engine to operate as efficiently as possible the top gear ratio is going to have to be dropped significantly, the engine downsized, or both. Weight won't matter much compared to aero at that speed, so your best bet is to keep all the creature comforts and concentrate of aero then gearing. Basjoos could see ~130+mpg@65mph IMO w/ a taller fifth. You can also go diesel if you wanna "cheat" since diesel has ~12% more energy per gallon than gasoline and peak engine efficiency for gas/diesel is about the same.

and diesel has lower end torque, so you would keep the vehicle in motion with a lower engine speed, so you could run a higher last gear at around 1700 at 60 or so.

Low end peak torque depends more on displacement/cam than anything else, and gassers tend to have better air utilization rates than diesels so they can make more peak torque down low all things being equal.

you still benefit from a diesel than gas because a diesel has no throttle plate

Gas has no throttling at peak efficiency/torque anyway, which is what's needed for 200mpg@65mph in even a small car.

Next question:

It looks like the priorities would be

Aerodynamics
transmission
powerplant

Lets talk aeroeynamics first

Assuming that our base vehicle is a 96+ geo metro how would you mod it aerodynamically? Sky is the limit.

Half width, half height, tandom 2-seat, elongated teardrop overall shape, no exterior mirrors or doorhandles, fully faired skinny wheels with smooth fillets to transition right angles to the body.

A halving of reference are alone should put the vehicle within the 200mpg figure w/ a modest boat tail, something like that may be capable of breaking into the 300mpg arena w/ a steady state cruise.

Something shaped approximately like the Jet Car, or VW 1L car.

http://www.metrompg.com/posts/photos/jetcar.jpg

This was made with Gen1 smart car (diesel) running gear.

For reference, this vehicle is capable of about 100 mpg (US) at about 100 km/h average speed.

Has anyone thought of fitting an aircraft canopy to a mod. Here is link to canopies.

aircraft canopies

Based on the above, a narrowed Geo fitted with one on these canopies could be awesome.

For a simple shape, I like the idea of a split down the center ice cream cone from the low beltline up and then vertical slabbed below that with 3 wheels - tadpole styled. Rear direct drive at speed on the highway, hub motors up front that have no drag at speed for accel/decel.

I just don't know how aero the shape would be. The ice cream cone itself is extremely aero so whatever affect the vertical sides would have is the big question but it would keep it simple to fabricate.

Already been done

Google VW 1L car

250 + mpg

Holy cow! silverinsight2 - the link you originally posted has this photo:

http://darmowa-energia.eko.org.pl/pl...to/vw/vw_9.jpg

This is the first picture I've seen with a person in the frame. The 1L is much smaller than I thought (not that there's anything wrong with that!). And I had seen many pictures of it before this one.

http://www.recumbent-bikes-truth-for...e%20Closed.jpg

Something like this, but with bigger wheels and powered by a scooter engine.

WOW!!! Judging by the guy in the background, the car is only about 3 feet high! or less! I think my front bumper is taller than that! judging by the man sitting in it, my front bumper would smack him in the forehead, followed by the radiator in his skull... that's like the size of a shifter cart and as tall as a decent 4 wheeler!

Little over four, but yeah, it's essentially a Honda hatch cut in half. Here's another pik w/ the same person.
http://www.canadiandriver.com/news/0.../vw1litre7.jpg

I have some formulas that would help to figure out what is required to do that. Here are two useful ones:

MPG=2343.75/(BSFC*F)

P=F*V/375

We can guess that the BSFC will be about 0.5 lb/hp*hr and we know that the MPG=200 so I'll rearrange the first formula to determine F (force in pounds).

F*MPG=2343.75/BSFC
F=2343.75/(BSFC*MPG)

F=2343.75/(0.5 * 200)
F=23.4375

Now I can calculate horsepower from F and V.

P=F*V/375

F=23.4375 LB
V=65 MPH

P=23.4375*65/375
P=4.0625 HP

I heard on the radio that a Ford Taurus has such low drag that it requires only 21 HP to go 65 MPH. The 200 MPG car needs to have its total drag reduced to less than 20% of the Taurus. This would require a very small frontal area, low coefficient of aerodynamic drag, light weight and very easy rolling tires. It should be possible. There are some streamlined bicycles that can go 60 MPH on about 1 HP of human muscle power. It should be no big problem to adapt to engine power and go 65 MPH on less than 4 HP. Of course the car would have to have a much smaller than normal engine. A one cylinder engine with about 200 cc (0.2 liter) seems about right for making 4 HP efficiently.

I found some pictures of a streamlined bicycle here:
Coslinger special HPV streamliner recumbent bicycle

Here is a graph of MPG vs speed for super efficient vehicles:
Super-Mileage Vehicle Fuel Economy as a Function of Speed

isn't VW planing to build the 1 liter car? only using a more common plastic for the body instead of carbon fiber, and aluminum for the safety cage instead of magnesium, with a goal of 180-190mpg? I know that early on they weren't planing to build it because it would have to sell for around $17,000 but I suspect with the cheaper design it might sell for less.

I read that they will build a limited number of them starting in 2010. Check this article.

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