The oil within a cartridge vaporizes at different temperatures based on brand, strain, or batch. If your oil is burning faster than normal, it might be because the voltage on your vape pen is too high and is burning the oil quicker than usual (It may also taste a little burnt). 

The recommendation is to reduce the voltage on the battery you are using. Most brands will provide ideal temperatures at which to consume their product, it is important to find the ideal temperature for your cartridge, on your battery if it has settings to reduce the voltage. Please adjust these settings to get the best possible outcome for your cartridge purchase.