  The first computation of the compressible energy transfer rate from $\sim$
0.2 AU up to $\sim$ 1.7 AU is obtained using PSP, THEMIS and MAVEN
observations. The compressible energy cascade rate $\varepsilon_C$ is computed
for hundred of events at different heliocentric distances, for time intervals
when the spacecraft were in the pristine solar wind. The observational results
show moderate increases of $\varepsilon_C$ with respect to the incompressible
cascade rate $\varepsilon_I$. Depending on the level of compressibility in the
plasma, which reach up to 25 $\%$ in the PSP perihelion, the different terms in
the compressible exact relation are shown to have different impact in the total
cascade rate $\varepsilon_C$. Finally, the observational results are connected
with the local ion temperature and the solar wind heating problem.
