Why don't i get 4g on my iphone 5?

I have an iphone 5 with sprint and there's no towers in my area but i still get 3g when i drive through philly where towers are located

Sprint does NOT have a very good network.AT&T's network far surpasses the network capabilities and features that Sprint has.AT&T, has better service and 4G LTE in the area you were in, whereas, with Sprint, they don't have 4G LTE in the area you were in.

Unless you want to cancel your Sprint contract, you probably won't have 4G LTE for a while.

Always check with Sprint to see if 4G LTE is coming to your area.