VA Clean Special Fuel Plate

[mcbrunnhilde]

Those were probably existing plates and Virginia decided not to alter them for the hybrids. In California, alternate-fuel vehicles got stickers just like hybrids, but they are silver and not yellow.

[gforeman]

Doesn't the use on I-66 end July 1, 2007? Or did they extend it?

[NoMoShocks]

<div class='quotetop'>QUOTE(dishpan @ Jun 22 2007, 09:35 AM) [snapback]466377[/snapback]</div>

why is a hybrid a "clean special fuel" anyway, according to VA? it still uses gasoline. its not like it run on vegetable oil.
[/b]

Because it uses the Atkinson Cycle Engine, and the RPMs are kept up in the higher most efficient range where feul is burned most completely.

Several of the current hybrid vehicles, vehicles like the Ford Escape and the Toyota Prius, use Atkinson cycle engines in stead of the conventional Otto-cycle. See an animation of the Atkinson Cycle engine again from Matt Keveney's excellent engine animation site. http://www.keveney.com/Atkinson.html

The Atkinson-cycle engine is up to 10% more efficient than a conventional four-stroke petrol "Otto" engine. The increase in efficiency comes mainly from controlling the so called pumping losses.

Pumping losses are caused by the way power output from a petrol "Otto" engine is regulated. It is regulated by controlling, or rather constricting airflow to the engine. This constriction of airflow creates partial vacuum (low pressure) in the inlet manifold. Maintaining this "low pressure" in the inlet manifold wastes energy.

One reason for diesel "Otto"-engines being more effective than the corresponding petrol engines is because there is no pumping loss in a diesel as power is regulated by injecting less fuel into the cylinders and not by choking the airflow to the cylinders.

The pumping losses in an Atkinson cycle engine are reduced by allowing, in the compression stroke, a small amount of the fuel/air mixture to flow back from the cylinder into the induction system, without being burned, thus reducing the effective displacement of the engine.

Additionally as the expansion ratio of an Atkinson cycle engine is greater than its compression ratio it takes more heat from the exhaust gas instead of pumping it into the exhaust system, thereby achieving additional efficiency.

The Atkinson cycle — also called the "five-stroke cycle" (because of the backflow which is really not a cycle) — works like this: intake, backflow (partial expulsion to eliminate pumping losses), compression, expansion, and exhaust.

The combustion chamber volume is adapted to maintain a constant compression ratio to avoid knock while increasing the expansion ratio to optimize efficiency.

[mcbrunnhilde]

<div class='quotetop'>QUOTE(G-Man @ Jun 22 2007, 06:41 PM) [snapback]466686[/snapback]</div>

Doesn't the use on I-66 end July 1, 2007? Or did they extend it?
[/b]

I believe it was extended to 2008 sometime in February of this year.