In sensor routing algorithms, energy efficiency is considered as the main concern since every node is batterypowered. However, some sensor applications require high priority feature like delay-guaranteed data deliveries if it is critical to notice important events within a predefined deadline such as in surveillance systems. In this paper, we set up a data delivery scheme making use of variable transmission range and propose a way to determine the optimal transmission range to provide statistical delay bound and energy efficiency. Note that these two metrics are in the tradeoff relation. And then, we apply our scheme to GEAR [8] to achieve energy awareness which is critical to extend the lifetime of sensor networks. Furthermore, we identify the delay reaction phenomenon, a big obstacle in providing guaranteed delay, and also propose two experimental counter-plans to remove this phenomenon.