The ProMaster's front-wheel-drive layout gives it a genuinely different interior shape than the Sprinter or Transit — wider usable floor space, which changes layout planning meaningfully.
ProMaster 136" Wheelbase (High Roof)
| Measurement | Approximate Dimension |
|---|---|
| Interior length (cargo area) | ~140" |
| Interior width (wall to wall) | ~74" |
| Width at floor (flat, no wheel well intrusion) | ~68" |
| Interior height (high roof) | ~76" |
ProMaster 159" Wheelbase (High Roof)
| Measurement | Approximate Dimension |
|---|---|
| Interior length (cargo area) | ~163" |
| Interior width (wall to wall) | ~74" |
| Width at floor (flat, no wheel well intrusion) | ~68" |
| Interior height (high roof) | ~76" |
The Flat Floor Advantage
Because the ProMaster is front-wheel-drive, there's no drivetrain hump running down the center of the floor, and the wheel wells intrude far less into usable width than on the Sprinter or Transit. The result: roughly 68" of usable flat floor width, meaningfully more than the ~48" usable width you get between wheel wells on a Sprinter or Transit. This is the single biggest layout advantage of the ProMaster — a queen bed can often be placed sideways (width-wise) more easily, and walkways feel less cramped.
Tallest Interior Height of the Three
At roughly 76" in high-roof configuration, the ProMaster typically offers the tallest standing height of the three major conversion vans — a real advantage for taller builders, though as always, physically standing inside one before committing is worth it given real-world variance from flooring/ceiling build-up.
What These Dimensions Mean for Layout Planning
- 136" wheelbase: The extra width makes even the shorter wheelbase workable for a side-facing fixed bed without needing the full length a Sprinter or Transit would need for the same comfort.
- 159" wheelbase: Combines the width advantage with enough length for a full kitchen, fixed bed, and small bathroom — often considered one of the most spacious layout options among mainstream conversion vans at a comparable price point.
Frequently Asked Questions
Is ProMaster interior bigger than Sprinter? Usable floor width is meaningfully bigger due to the flat floor and smaller wheel well intrusion, and standing height is typically taller. Overall length is comparable at equivalent wheelbase options.
Can you stand up in a ProMaster van conversion? Yes — high-roof ProMaster offers roughly 76" of interior height, generally the tallest of the three major conversion van options.
Why does the ProMaster have more usable width than a Sprinter? Its front-wheel-drive layout eliminates the drivetrain hump and reduces wheel well intrusion into the floor, leaving more flat, usable width for layout planning.