Why is designing a 40 MPG car called "Rocket Science"?

First I have never seen a Smart car billed as a miracle. Not sure what Kool-aid your drinking. 

I imagine the reference is figurative not literal. Look at the "green" marketing by auto companies these days - completely unremarkable forms of change are billed as hard won "progress" in the "fight" to overcome technological hurdles to bring us - the now admiring public - the best that modern technology can offer. And, like marketing tends to be, its a bunch of hogwash.

It isn't.

This is rocket science ~ F = (m dot * V)e + (pe - p0) * Ae

LOL, real rocket science. (-;

Couldn't resist it.

You also have to look at weight in respect to building materials. Steel is the material of choice because it is strong and inexpensive to use in manufacturing cars. Newer materials, carbon fiber and composites would make a lighter car equal to or greater in strength to steel. The problem is cost of manufaturing is much higher than steel. The tools, dyes and molds needed would also be a huge capital expense. I believe this technology will eventually be used to build cars but not until the cost of these new technologies comes down and the big car companies decide to invest in this new technology.

The problem is not directly the cost of actual manufacturing, but as you point out the really expensive part is re-tooling auto industry with Composite manufacturing technology. Also realize that the composite manufacturing is still not really mature when it comes to large scale mass production. The good news is that a lot of companies are inreasingly using composites in their high performance cars and as the technology becomes more fimiliar and the initial R&D costs are recovered, we may see some of it in family vehicles soon. Unfortunatley where a composite vehicle completely looses it is in the mass in a collision mass still wins. We have this tendency to pick the worst case scenario of Tractor Trailer smashing into a car as a goal post of safety, that is not realistic. If any one wants to get really serious about introducing light cars, the first step will be to restrict and / or completely ban the use of lift kits in pick up trucks. It will also be needed to restrict the empty weight of the non commercial vehicles sold. But our policies are largely driven by two extreme forms of ideology and not by science, so I dont have any hopes.

I wouldn't want a carbon fiber or other composite framed car because of failure mode. Metal fails via plastic deformation, stretching (and thus absobing energy) in an impact, wheras composites just snap.

A frame made of 7075-Al, however, would be a verry nice thing!

A modern Toyota Yaris 5-speed manual transmission car will get 40+ mpg if you drive it as slowly as a Geo Metro will go, in spite of what the EPA sticker states.
My worst tank ever was a 70 mph highway trip against a brutal headwind, got 36.1 mpg. The Geo I owned could also be driven down to the upper 30's mpg if driven in a similar situation.

It's interesting that back in the 1940's, Nash made a model called the 600. It got its name because it would presumably travel 600 miles on a 20 gallon fill-up of the gas tank. I did know owners who would achieve 25 mpg + with these cars. These cars hauled 6 passengers and weighed about 3000 pounds. The engine was a side valve 6 with 172 cubic inch displacement. The 1949 model had true aerodynamic styling as it was designed with extensive wind tunnel testing.

It would seem that with today's more efficient overhead camshaft engines we could have achieved 40 miles to the gallon with a full sized automobile. However, people thought that the "Airflyte" styling was ugly. With plentiful, inexpensive gasoline, we moved to the finned monsters of the late 1950's. We had Buick's Dynaflow and Chevrolet's PowerGlide that depended on the torque converter rather than gearing for torque multiplication, and had plenty of slippage. Even after the mid 1970's when we had a gasoline crunch and small cars became popular, after the crunch we went to SUV's. Had we made a sustained effort to improve on the Nash design, we might have full size 40 mpg cars.

Agreed. I second the notion that had we as a country made an effort to deal with the oil-gasoline issue after the first gasoline crunch of the 1970s we might be driving alcohol fueled vehicles like the folks do in Brazil. We need a real effort to find an alternative fuel. Rocketman

in england most of our cars will average 40mpg,but most are small cars with 1.3 litre engines,also because of our rediculous petrol prices, (currently the equivalent of $10 a gallon!!),a lot of people are buying turbo diesel.my nephew drives a seat leon,(made by vw)with a high output 2.0 tdi engine,which developes 170 bhp!and will do 130mph!and he averages 45mpg!so maybe turbo diesels are the way forward in the usa?

I wish there were easily available small econobox diesels on the market in the US. As far as I know the only one widely available are the VWs which I wouldn't touch w/ a 10ft pole - I'd rather drive a car more often than it is in the shop being fixed.

i know what you mean!vw cars are not as reliable as people think,in england just about every manufacturer offers small diesel engine vehicles which easily get 40 mpg in town,and up to 65mpg on the motorway!no wonder theyre selling so well here in the uk,with our rediculously high petrol prices.i dont know why manufacturers dont import them into the usa,they have to meet strict euro 4 emissions standards over here,so i dont know why ford doesnt sell our european fiesta and focus with their excellent peugeot diesel engines in the usa?theyre smooth,quiet and quite powerful too!long gone are the days of dirty,noisey and slow diesels!

I wish more Euroboxes were available in the US. I particularly like Seat and have always regarded it as VW's nutcase division. Anything dramatic or interesting that VW don't consider within image keeping is given to Seat and they've made it very successful. They make good cars, in fact their build quality seems to be better than VW these days.

I love their hotrods.

It's a game of the marketplace and we're pawns within it. As soon as we get used to smaller 40 mpg diesels and $4.50 a gallon for diesel fuel the price will skyrocket again . . . maybe even to $10 a gallon. Used to be a time when gas prices went up even a few cents that suppliers pointed to a reason . . . a hurricane in the Gulf . . . or Mid-East wars interrupting supply . . . or something. Nowadays, prices change from hour to hour with no rationale or reason. The people who own the oil are simply making the most money that they can . . . look at profits posted by the gas companies. I know that this is a can of worms but we should really look to alternative fuels for our vehicles. Rocketman

Currently, you can, legally, make so many gallons of alcoholic beverage a year without paying the "luxury", or "sin" tax on it. It might be difficult to remove enough of the water from the alcohol to make it pure enough. There's enough technical data out there to find out how to do it.
Now, if you had an alcohol burning engine........................................!

So that you will be willing to pay more for it. A Delta or Atlas rocket launch can cost over $400 million. What a deal that high priced ForTwo is compared to those high priced sleds!

The Plymouth Horizon was a miracle. Darned if you couldn't run 440 miles on the highway on a single tank with the stripped down ones and get 42 MPG. Fifth gear wouldn't climb hills but fourth sure would. Mine was cheap to operate from one end of Rt. 40 to the other.

Did yours have the Volkwagen engine? Early models used the Rabbit engine and got great gas mileage. Later ones with Chrysler 4 banger were less frugal.

we can ,they just choose NOT to. IT'S that cut and dry.


maico