Minivans are a totally different class of vehicle than the actual problematic vehicles, body on frame suv’s and pickups, though. I wager they are significantly lighter too because they are unibody and based on car platforms. The problem is that most people who are really in the market for a minivan don’t buy minivans anymore, they buy crossovers, which are either cars or minivans (the caravan, the first minivan, was based on the chrysler k platform, anyways) made up to look like a big box, non-aerodynamic, and in most cases, “rugged” (or “sporty”) suvs.
