As the others said, keep the low gearing for a bit. When you go to a higher gear, swap out cogs in the back rather than the front chainring. It's easier, cheaper and the difference will be more noticeable.
A 46-16 is 75-76 gear inches. Going to a 48-16 would only get you to 78-79 while the 46-15 would take you to 81 gear inches.