The Tata Sierra is clearly the larger of the two cars and will give you more space than the Maruti Fronx, as well as a better ride, too. However, the base version of the Sierra isn't as well-equipped as the Fronx.
More importantly for you, the versions that fit your budget come with the 1.5-litre naturally aspirated engine, which is quite weak in its power delivery and not ideal for you, given that you are mostly driving on highways. Thus, a high variant of the Fronx would suit you better.


