I believe it was a 2012 Volvo 670 with D12 automatic transmission. I was told it only had a 4-5 gallon DEF tank.
Q. What is the shelf life of DEF? A. The shelf life of DEF is a function of ambient storage temperature. DEF will degrade over time depending on temperature and exposure to sun light. Expectations for shelf life as defined by ISO Spec 22241-3 are the minimum expectations for shelf life when stored at constant temperatures. If stored between 10 and 90 deg F, shelf life will easily be one year. If the maximum temperature does not exceed approximately 75 deg F for an extended period of time, the shelf life will be two years Source: http://www.cumminsfiltration.com/pdfs/product_lit/americas_brochures/MB10033.pdf
I'm finally starting a new job next week, my truck will have a 6000 gallon DEF tank on it. I will be hauling bulk DEF to truck stops. Adam