Opti-Rate Replacement Leaf Springs (Pair) – Ford Transit (2015–Present)The Opti Rate Replacement Leaf Springs are the result of more than a decade of engineering, testing, and real world refinement across every type of Transit buildfrom lightweight adventure vans to fully outfitted expedition rigs. Traditional leaf spring upgrades force owners to choose a specific spring rate or lift height based on estimated final weight, often requiring guesswork or last minute changes once a build is complete. The Opti Rate system