Complete air intake systems will definitely provide a better performance increase.What is a decent Cold Air Intake for my 2010 Xb? I hear that it isn't necessary to buy a $300 intake like Injen or K&N. I also see people using $60 intakes and sound pretty good swell.
The most powerful intake Injen® - SP Series produces up to +14HP. Intake tube relocates the filter closer to a fresh air source - that's the main advantage. On the other hand you can get a performance filter for $60 and attach it to a stock tube, but it wouldn't give a good increase. It should be something like +1-3HP
You can check Air intakes and performance filters for your 2010 Xb on our website: 2010 Scion xB Cold Air Intakes at CARiD.com