This work analyzes the characteristics of the small-scale fading distribution in vehicle-to-vehicle (V2V) channels. The analysis is based on a narrowband channel measurements campaign at 5.9 GHz designed specifically for that purpose. The measurements were carried out in highway and urban environments around the city of Valencia, Spain. The experimental distribution of the small-scale fading is compared to several analytical distributions traditionally used to model the fast fading in wireless communications, such as Rayleigh, Nakagami-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>m</mml:mi></mml:mrow></mml:math>, Weibull, Rice, and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi mathvariant="normal">α</mml:mi><mml:mtext>-</mml:mtext><mml:mi mathvariant="normal">μ</mml:mi></mml:math>distributions. The parameters of the distributions are derived through statistical inference techniques and their goodness-of-fit is evaluated using the Kolmogorov-Smirnov (K-S) test. Our results show that the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>α</mml:mi><mml:mtext>-</mml:mtext><mml:mi>μ</mml:mi></mml:math>distribution exhibits a better fit compared to the other distributions, making its use interesting to model the small-scale fading in V2V channels.