- DEF can expand by up to 7% when frozen. Therefore, it’s vital to keep storage tanks less than full to avoid damaging them.
- Al Warren Oil’s Expert Advice: Invest in DEF-specific, insulated bulk storage tanks. If you’re thinking about storing multiple products in the same tank, think again. These tanks should only be used for DEF and must be thoroughly rinsed with either distilled or de-ionized water, or on-spec DEF before switching contents.