[NeilBlanchard]

Greetings,

I've been ruminating on what a (much) more efficient automobile would look like, and here are some random thoughts:

We need to use a smaller motor, while still getting enough power out of it, so maybe 1.0-1.3L four cylinder (or maybe even smaller?), with a small turbo? It would also have variable valves, to maximize the low RPM torque (fewer valves with shorter duration, IIANM), and then more valves for longer duration, etc. at higher RPM's. This same mechanism could be used to shut down two of the four cylinders at idle, and in low-demand situations, and then all four cylinders could seamlessly be brought back into operation as more power is demanded. (Maybe with a split crankshaft, and a hydraulic clutch between the halves; to reduce the drag of the non-firing cylinders?) It would not be too hard to have the entire engine be shut off when sitting still.

The transmission would have 6 to 8 speeds; again to help utilize the available power. I would want a manual transmission, but the clutch would be used only in first (or second) gear for getting rolling. Thereafter, gearshifts should be handled like they are in an Formula 1 car: shift paddles under the steering wheel to shift up or down, with the ignition computer "blipping" the engine momentarily while the transmission shifts. In Formula 1 cars, this happens at a mere 19,000RPM, with a 7 speed transmission -- so I can't see why it couldn't be done at 2,000-6,000RPM?

This scheme would allow a direct drive situation with virtually no slippage once the car is rolling. Also, the throwout bearing in the clutch should be well lubricated for coasting. I think that a manual transmission has much better control, for driving in typical New England winter conditions, for example.

All the aerodynamics should be improved to a point where the drag is reasonably close to ideal, without becoming impractical. The underside should be included in this, and also low rolling resistance tires are also key. A while back, I remember seeing tweaks like partially recessed side mirrors, that reduced the aero drag -- this seems like a reasonable thing to do, too. (Or, using video cameras and display screens; al la Aptera?)

There are (at least) five or six things that automobile makers could do to improve the efficiency of all cars/vehicles:

* Using the variable valve technology that is already in many engines, to not only improve the power band (less air flow at low RPM's for more torque, and more air flow at higher RPM's for more horsepower) -- but to also use it to shut off cylinders, when they are not needed. A few V8 engines already do this, and transform themselves in to 4 cylinder engines, when the extra power is not needed. So, why not turn a V6 into a 3-cylinder, or a 4-cylinder into a 2-cylinder? Seems to make a lot of sense to me!

* The Toyota Prius (2nd gen?) uses a vacuum-insulated tank (like a Thermos) to hold hot engine coolant overnight, to be pumped into the engine block to allow it to come up to a good operating temperature much more quickly. This could/should be done on all vehicles, and it would greatly reduce emissions and fuel use at the start of every trip.

* Preheat the fuel right before injecting it into the cylinders -- this will vaporize the fuel (as opposed to simply making it into droplets). This will help increase the power and efficiency of any engine dramatically!

* Use a CVT (continuously variable transmission) instead of a automatic transmission with a torque converter. A CVT transmission provides nearly zero slippage, and it helps the engine operate at the RPM that is best for the situation, and the ratios are infinitely variable, and there is no lag time while you shift.

* Using a CVT transmission makes it possible to do something that the Honda Civic Hybrid (and others) does, and that is shut off the engine when the vehicle is stopped. The instant the driver removes their foot from the brake, the engine is started and it goes on it way, without you even being aware that it was not running.

* Work on reducing both rolling resistant, and aerodynamic drag -- both the underpan of the vehicle and the body, too. Tandem with this, there should be an alarm for when the tire pressure drops below optimum.

* Serial electric hybrids may be the most efficient way to move a car -- they allow you to regain energy through regenerative braking, and plug it in to charge, too.


Can you think of other improvements?