Replace the factory after-axle steel tank on 2011-2016 Ford F-250, F-350, F-450, and F-550 6.7L Powerstroke cab chassis trucks with S&B's 40-gallon crosslink-polyethylene tank. This is a same-capacity replacement designed to address the OEM steel tank delamination issue, not an extended-range upgrade. It reuses the OE sending unit, factory straps, and skid plate, and keeps the tank in the original after-axle location with the same ground-clearance profile. Notes: high-flow truck-stop nozzles may not shut off automatically, auxiliary tanks may affect S&B warranty coverage, and the tank is not transfer-pump ready.