This newest addition to Cessna’s CJ line, providing a step up from the CJ3, started deliveries in April 2010. The CJ4 is a mostly new design, but borrows its efficient swept-back wing from the larger Sovereign jet. The big wing holds more fuel, increasing range. Powerful new Williams engines boost the climb and cruise speeds. The cabin is about a foot and a half longer than the CJ3’s. Proprietary GreenTrak flight-planning software calculates minimum total trip costs.