Question

can methane be used as a fuel in car

Answer 1

no it can`t be cuz its costly

Answer 2

No, because at room temperature methane is a gas. Next time you fart, breathe in the methane. So you can't just put a bunch of farts in your gas tank, it's not gonna work out. You could still burn it though, however you'd need to completely make a new way of containing all the gas so that you can burn it in a practical manner.

So you could in a sense use it to power your car, since that's all you're really doing in the first place is burning fumes of hydrocarbons. Practically speaking, no.