def price per gallon
Terra Environmental Industries has begun production of DEF at a facility in Oklahoma, where it will make 30 million gallons of TerraCair DEF per year. Price points The fluid's cost is coming down from when it first appeared on the market, when it was more than $12 per gallon. A NAPA auto parts store in Columbus, Ohio, sells a 1-gallon jug of Valvoline-brand DEF for $5.79 and a 2-gallon jug for $11.99. North of the city, a Flying J sells BlueDEF in a 2.5-gallon jug for $13.99, or $5.60 per gallon. The truckstop has installed an underground storage tank with fuel-island dispensers, and they should be operating by early June, a clerk says.