Without the electric motor and batteries the Prius would require a larger gas engine. Also the tricks like regenerative braking wouldn't be there any more. 44 MPG is about as good as it's going to get no matter what car you choose.

It seems very logical that when driving with few stops on near level roads the hybrid paraphenalia is just dead weight. It would be helpful to know when the hybrids are more economical. I feel sure that driving on West Texas interstates would cost more in a hybrid than a similar non-hybrid.

Hybrids achieve their best mileage in stop and go traffic. The electric motor generates ample torque to get the car moving. Electic motors get less and less effiecent the faster they go, and generally don't have gearboxes to compensate. So on the highway a hybrid car must use it's gasoline engine almost all the time to maintain speed.

Hybrids achieve their best mileage in stop and go traffic. 

That isn't true of all hybrids. The Civic Hybrid gets better fuel economy on the highway because, unlike the Prius, it runs primarily on the gasoline engine and the electrical engine only kicks in with you need extra power. If the OP is going to use the car mostly for highway driving, he should look at the Civic hybrid.

They do make cars that get really good highway mileage. They're called diesels. A VW Rabbit or Golf should easily get over 50mpg on the highway.

A Civic Coupe should get you about 40 mpg on straight highway driving (my brother gets 38-42) for way less money than a Prius. Don't worry about 40 vs 44 mpg, there's very little money involved - Drive 20,000 miles at 40 mpg = 500 gallons, at 44 mpg = 455 gallons, a difference of 45 gallons or about $180. Nothing compared to the thousands more you'd pay for a Prius.

Agreed, everyone needs to do the math! We purchased a Camry 2 weeks ago. For the cost difference up front and insurance savings in our town, the break even for a hybrid was out at 8 1/2 to 10 years! We looked at a Fusion, I've bought nothing but Ford for the past 25 years and the Camry was obly costing us $638 more after 4 years. Yes the Camry was 2700 more up front, but again, the gas savings and insurance made up for it. And frankly, there was no comparison between the 2 in ride comfort, amenities and performance. I'm very disappointed in Ford............

Please fill me in on how many miles/year, what fuel price, and fuel mileage you based your calculations on.

As has been said or implied already, someone who does primarily highway driving is not going to derive enough benefit from a hybrid vehicle to justify the higher sale price. If you buy a "conventional" car that is highly fuel efficient, such as a Civic, a Corolla, a Sentra, a Versa, etc., your highway gas mileage will be almost as good as that of a Prius, and you will pay thousands of $$ less for it. For the saving of a few thousand dollars, you can buy a whole lot of gas if the very minor difference in highway mpg of these other cars bothers you.

Just as there are electric trains getting their power from overhead wires, and third rails, cars could use something similar. Since a third rail, carrying power, is potentially dangerous, the power could be transmitted by inductance, with the inductors embedded in the roadway. The cars would have electric motors designed to be energized by the inductors. These cars wouldn't have to carry batteries.

But we citizens would have to pay for the millions of miles of "track" required to make this dream a reality.

And the electricity has to come from somewhere. It is not free or pollution free.

True, but it would be a lot more efficient and create much less pollution.

Millions of miles of highways times millions of dollars per mile is, um, what is the name of that number, oh yea, trillions of dollars.

How can I give you an idea of just how much money a trillion dollars is? Let's give this a try, imagine twenty million pounds of $100 dollar bills.

Can the circuit be reversed to recover braking power?

I average 44 mpg in my 2001 Honda Civic HX (10% city, 90% highway driving routine -- that's at 65mph employing cruise control). The Honda Civic HX w/ manual 5spd is EPA-rated 39/44 pre-revision, 31/39 revised. Personally, I find the revised EPA projections to be overly conservative. The 2001-2005s have cruise control, which, vs. just your foot, makes a significant mpg difference on the highway.

I should mention the HX is the only Civic trimline sold in North America to be equiped the "lean-burn" VTEC-e engine ("e" for economy).

There is a lot more to the Prius than regenerative braking. The Prius engine uses an Atkinson cycle also known as an unsupercharged Miller cycle instead of the conventional Otto cycle. This engine uses something like a 14-1 compression ratio but since the intake valves wait until the piston is quite a ways up the cylinder before closing, the effective compression ratio is low enough to burn regular without pinging, yet you still have that full 14-1 expansion ratio on the power stroke to extract as much energy from the fuel as possible. Also, the engine throttles to a large extent by closing the intakes even later in the stroke instead of closing the throttle more which lowers the intake manifold vacuum and also the work the pistons have to do just to suck air into the cylinders.
This engine reportedly has a 34% thermodynamic efficiency even when only making 13.5 horsepower. Most conventional engines only approach this efficiency only at power outputs way too high for legal freeway speeds.

That's all true, but it all comes down to mpgs, and if they're just doing highway miles, there's lots of cheaper alternatives to a Prius get nearl as good or the same mileage.

I guess from the responses nobody seems to know what would happen to a Prius in HWY-only driving if you took all the electrical/regenerative parts out of the "hybrid" engine. I imagine a few extra MPG would result, but I still don't see why similar sized non-hybrid cars have so much trouble attaining more than about 35 MPG. Prius gets 44-46 HWY with all the extra stuff city oriented driving parts thrown in. Seems like a Toyota secret.

It doesn't take many horsepower to move a car at steady speeds on a level highway. The gas motor in the Prius has more than enough power for this. But the motor is a bit weak for acceleration from a stop. This is where the electric motor's characteristics help a lot- maximum torque is developed at 0 RPM. The gas motor in a non-hybrid car needs to be a bit more powerful(in a comparably-sized and weight vehicle), so uses more fuel, especially in stop-and-go driving. If drivers were willing to give up some power, non-hybrids the same size as the Prius could be made with much better fuel economy.