how large is the hydrogen fuel tank on a car and what is the most fuel efficent gas powered car in the us/06?

Question

and how long will that one tank last the driver

Answer 1

right now the tanks hold about 9 gallons each

Answer 2

Hydrogen cars come in two varieties, fuel cell vehicles and those with internal combustion engines (ICE). Fuel cell vehicles used compressed hydrogen and ICE vehicles use either compressed hydrogen or liquid hydrogen.

The BMW Hydrogen 7 is an ICE dual-fuel vehicle that runs on either gasoline or liquid hydrogen and has one tank for each fuel. The gasoline will power the vehicle for 300 miles and the hydrogen will power the vehicle for 125 miles.

There are a bunch of fuel cell vehicles that have been demonstrated so far and I have driven 9 of them. Depending on the vehicle, they usually have between 1 and 3 compressed hydrogen tanks onboard with a range of between 100 – 350 miles. The pressure on the tanks is between 3,600 psi and 10,000 psi.

My guess for the most fuel efficient hydrogen car would be the Honda FCX, which achieves about 57 mpg (comparable to gasoline). Other cars that may be close to this include the Ford Focus FCV, Mercedes F-Cell or Toyota Fine-T (Fine-X).

Answer 3

we're not there yet , BMW just released a H2 powered high speed experimental , everybody is so freaked out about hydrogen exploding it will be a while before we can re-educate everybody about it , then somebody has to get the cost of electrolysis down below the price of refining H2 from natural gas.