I usually use 1.8 coils but my friend Julie bought me 2 boxes of 2.5 coils there. Will they work the same as the 1.8 or do I need to bring them back and exchange them? Thanks Pam Bridge

Honestly it depends on your Juice, I noticed with my Sweet Stuff I needed a perfect amount of heat...very specific compared to other flavors.

Usually coils are optimized for a certain wattage...if you can find out the recommended watt range for your coil, you can use this formula to determine if they will work for your device. W = V^2/R or: Wattage = Voltage^2 / Resistance (Ohms)