crizh wrote:

Is it cold enough for efficiency to reach 112%? edit You can read that as 143% if you include the amount of energy wasted cracking the water in the first place. That is assuming that cracking water is 100% efficient. edit 2 This is a stupid argument. It is 14% more efficient to carry both the liberated Hydrogen and Oxygen from cracking water than it is to carry just the Oxygen and react it with atmospheric Methane. And that is still no more efficient than batteries.

Batteries aren't free, though. You're talking something like 200 credits per kg for the battery pack of 15.54 megajoules if USD=credits. If electricity costs 1 centicred for 3.6 megajoules, then after 200 charges of a 100kg battery pack (lets call it 10 years use - say 500,000 kilometers total) you'd have spent 863.33 credits on electricity, and 20,000 credits on the battery pack. If you pissed away two thirds of the energy, you'd have spent 2,581 credits on electricity. Assuming there's a positive interest rate, the liquid oxygen powered car is a vastly better buy. Presumably you could use cheaper batteries (room temperature superconductors are definitely not needed in the cold atmosphere of Titan) but bulk fusion power is *cheaper* than 1 centicred per 3.6 megajoules in Eclipse Phase (if you accept you can buy 1kg nuclear batteries that output 1 kilowatt for three years for 250 credits thats about 1 centicred per 3.6 megajoules, and presumably bulk fusion power power is going to be much cheaper than that).