\begin{tabular}{lccc}
\toprule
Test & $\chi^2$ & df & $p$ \\
\midrule
H1: nonlinear age terms = 0 (A2) & 340.1 & 6 & 2.01e-70 \\
H1: nonlinear mileage terms = 0 (A2) & 412.8 & 6 & 5.06e-86 \\
H1: all nonlinear terms = 0 (A2) & 663.6 & 12 & 2.73e-134 \\
H1: age $\times$ mileage tensor = 0 (A2t) & 661.2 & 49 & 3.69e-108 \\
H1: age profile $\times$ powertrain = 0 (A3) & 312.1 & 35 & 3.37e-46 \\
H4: region effects = 0 (A4) & 14.9 & 16 & 0.534 \\
\bottomrule
\end{tabular}