  A selection of the latest and most frequently used parton distribution
functions (PDFs) is incorporated in Pythia8, including the Monte Carlo-adapted
PDFs from the MSTW and CTEQ collaborations. This article examines the
differences in PDFs as well as the effect they have on results of simulations
and compare with data collected by the CDF experiment. Monte Carlo-adapted PDFs
do a better job than leading- and next-to-leading order PDFs for many
observables, but there is room for further improvements.
