A vehicle underfloor structure has: a battery pack that is disposed beneath a floor of a vehicle, and that is a power source that drives a motor for traveling that is installed in the vehicle; and a fuel tank that is disposed beneath the floor of the vehicle, and between a vehicle body front side end portion and a vehicle body rear side end portion of the battery pack as seen in a side view, and between vehicle transverse direction both end portions of the battery pack as seen in a plan view.

A fuel tank includes a fuel tank main body portion, a first supporting pillar portion, and a second supporting pillar portion. The first supporting pillar portion is provided at a vehicle rear side of an inner side of the fuel tank main body portion. The second supporting pillar portion is provided at a vehicle front side of the first supporting pillar portion at the inner side of the fuel tank main body portion and is longer in the vehicle vertical direction than the first supporting pillar portion is in the vehicle vertical direction.

A vehicle configuration wherein the center of mass of the vehicle is approximately superimposed upon the passenger and driver centers of mass when seated within the vehicle. An occupant's center of mass can be approximated using a standard center of mass position approximation, or a combination of any number of standard center of mass position approximations. The vehicle's center of mass can be approximately superimposed upon the occupant's center of mass in at least the longitudinal and vertical directions.

A recreational off-highway vehicle includes side-by-side passenger and driver seats held within a chassis that is approximately 50 inches wide. The seats sit low in the chassis and are covered by a roll cage. Grab handles are positioned on the sides of the passenger seat. Select large round tubing protects the vehicle, while rectangular tubing frames the portions of the vehicle beneath body panels. The vehicle is powered by an engine rearward of the seats that is connected to a transaxle. The engine and transaxle are isolation mounted together with a portion of the air intake assembly. The vehicle is suited for rough terrain travel.

A vehicle underfloor structure has: a battery pack that is disposed beneath a floor of a vehicle, and that is a power source that drives a motor for traveling that is installed in the vehicle; and a fuel tank that is disposed beneath the floor of the vehicle, and between a vehicle body front side end portion and a vehicle body rear side end portion of the battery pack as seen in a side view, and between vehicle transverse direction both end portions of the battery pack as seen in a plan view.

A vehicle body structure includes a rear floor panel, a first rear cross member, a fuel tank and a VSF valve. The rear floor panel includes a first wall and a second wall. The first rear cross member includes a pair of first vertical walls extending in an upward/downward direction, and a first horizontal wall configured to connect lower ends of the pair of first vertical walls. The fuel tank includes a second connecting surface extending along the first horizontal wall. The first horizontal wall includes a pair of horizontal sections and an inclined section. The VSF valve is installed at a position overlapping the inclined section in a forward/rearward direction of a vehicle body.

A vehicle underbody assembly including a pair of rockers, a pair of side rails, a first cross member, a second cross member, and a fuel tank is provided. Each of the pair of side rails is secured to a rearward portion of one of the rockers. The first cross member extends between the side rails and is thermally treated to form a first central hard strength zone between two first soft strength zones. The second cross member is arranged with the pair of side rails and the first cross member to form a rectilinear frame and is thermally treated to form a second central hard strength zone between two second soft strength zones. The fuel tank is secured between the pair of side rails so that the fuel tank is located within a rectilinear frame formed by the pair of side rails and the cross members.

A recreational off-highway vehicle includes side-by-side passenger and driver seats held within a chassis. The seats sit low in the chassis and are covered by a roll cage. Grab handles are positioned on the sides of the passenger seat. Select large round tubing protects the vehicle, while rectangular tubing frames the portions of the vehicle beneath body panels. The vehicle is powered by an engine rearward of the seats that is connected to a transaxle. A radiator is positioned above the engine. A cover with an access panel is situated between the engine and the passenger seats. The vehicle is suited for rough terrain travel.

A vehicle body structure includes a first middle floor unit for a gasoline vehicle and a second middle floor unit for a hybrid vehicle, and the first and second middle floor units are made interchangeable with each other. A front floor unit and a rear floor unit are made shareable by the gasoline vehicle and the hybrid vehicle. That is, the front floor unit and the rear floor unit can be regarded as a platform. Additionally, the second middle floor unit includes a housing, and an IPU is stored in an interior of the housing.

A fuel cell vehicle includes a first tank, a second tank, first and second valves for releasing gas, a gas passage for supplying gas to a fuel cell via the first and second valves, a pressure-reducing valve for decompressing the gas, side members disposed on the respective sides of the vehicle, and a motor disposed rearward of the second tank and configured to drive wheels. The first tank is not disposed downstream of the second tank, on the gas passage. The pressure-reducing valve is disposed in a region located rearward of a rear end of the second tank in a vehicle front-rear direction, forward of a rear end of the motor in the vehicle front-rear direction, and between one of the side members and an extended line extended in the vehicle front-rear direction from a side wall of the motor. The pressure-reducing valve is disposed on the second valve side.