Yup. There's a quite measurable increase in drag thru the rod - probably not enough to worry about under normal circumstances, but if you are fishing ultralight, or redlining on heavier line, it's definitely a consideration. I really don't know the formula, and I'm sure someone out there will, but that's why it's imperative to measure the reel drag thru the rod, rather than by itself. When you add up the friction generated by guides - even Sic's, as well as the rod's natural tendency to want to straighten, it increases exponentially.
Give it a try - you may well be surprised!