A valve group housable in a conduit of a pressurized oil circuit, wherein said conduit is in fluid communication with a vehicle operating group and with a heat exchanger group, wherein said conduit extends along a conduit axis (C-C) comprising conduit side walls and a first conduit opening and a second conduit opening positioned axially spaced apart on the conduit side walls fluidly connected to the operating group and the heat exchanger group, respectively; wherein the valve group extends in length along an axis (X-X) coinciding, in a configuration housed in the conduit, with the conduit axis (C-C), and comprises: i) a valve body, comprising a body cavity, extending along the axis (X-X), between a first end through which the oil entering the body cavity flows and a second end axially spaced apart, wherein the valve body comprises a first body opening and a second body opening positioned axially spaced apart, so as to face, in a configuration of the valve group housed in the conduit, the first conduit opening and the second conduit opening, respectively, wherein the valve body further comprises at least one guide slot extending axially with respect to the axis (X-X); ii) a shutter, extending along the axis (X-X), comprising a shutter body fitted, axially movable, onto the valve body, so as to be, in a configuration of the valve group housed in the conduit, radially positioned between the valve body and the conduit side walls, wherein the shutter comprises, on said shutter body, a first shutter opening and a second shutter opening, wherein the shutter comprises a guide element extending radially through the guide slot; iii) a control device engaged with the valve body and the shutter to control the position of the shutter along the axis (X-X) between a base position in which the hydraulic passage section defined by the alignment of the first shutter opening to the first body opening is greater than or equal to the hydraulic passage section defined by the alignment of the second shutter opening with the second body opening, and an adjustment position in which the hydraulic passage section defined by the alignment of the first shutter opening with the first body opening is smaller than the hydraulic passage section defined by the alignment of the second shutter opening with the second body opening. i) a valve body, comprising a body cavity, extending along the axis (X-X), between a first end through which the oil entering the body cavity flows and a second end axially spaced apart, wherein the valve body comprises a first body opening and a second body opening positioned axially spaced apart, so as to face, in a configuration of the valve group housed in the conduit, the first conduit opening and the second conduit opening, respectively, wherein the valve body further comprises at least one guide slot extending axially with respect to the axis (X-X); ii) a shutter, extending along the axis (X-X), comprising a shutter body fitted, axially movable, onto the valve body, so as to be, in a configuration of the valve group housed in the conduit, radially positioned between the valve body and the conduit side walls, wherein the shutter comprises, on said shutter body, a first shutter opening and a second shutter opening, wherein the shutter comprises a guide element extending radially through the guide slot; iii) a control device engaged with the valve body and the shutter to control the position of the shutter along the axis (X-X) between a base position in which the hydraulic passage section defined by the alignment of the first shutter opening to the first body opening is greater than or equal to the hydraulic passage section defined by the alignment of the second shutter opening with the second body opening, and an adjustment position in which the hydraulic passage section defined by the alignment of the first shutter opening with the first body opening is smaller than the hydraulic passage section defined by the alignment of the second shutter opening with the second body opening.