Interesting Lithium Battery on sale

[mudnut]

This from their website:

Being Lithium, the voltage is held higher and longer than a lead acid battery. This means your vehicle will supply a stronger spark to burn fuel more efficiently, giving more power for the same fuel. Increasing fuel efficiency, giving better mileage and savings of up to 8%. Once the fuel is burnt more efficiently the exhaust emissions are decreased and this is better for the environment.

What a load of garbage, this alone would put me off buying anything from these guys!

You are right as the vehicle has a voltage regulator anyway. Energy is energy. If you take (example only) 1000 watts to crank the starter, it will take 1000 watts plus efficiency losses from the engine to recharge the battery. And it may be a weight saving that might add up to only $10-$20 a year.