"Help in doing something" or "Help doing something"

Is the preposition in necessary or abundant?

To be specific, which of these two sentences sounds better/is correct?

This helps in achieving better fuel economy.

or

This helps achieving better fuel economy.

I know of this question, however I am not sure how much it applies to my problem.

Solution 1:

Both constructions are grammatically sound. In the first example, in achieving is a prepositional phrase the object of which is the gerund, achieving. In the second example achieving is a present participle. One spelling and two parts of speech! This would have a clear antecedent in context. For the sake of argument, lets say the this is referring to "careful driving." Why not use that antecedent and make the sentence clearer and more active: Careful driving achieves better fuel economy.