As others have stated. DSL speed is totally dependent on the cost of the service. Some start as low as 19.95 for basic and go up from there. So that is one thing to check out.
The other is the distance from the router. Is it G or N? G has a short distance issue and 40 feet could be giving you a very weak signal independent of the speed. But your wifi may be G only also. Unless you upgraded your wifi in the 2009 computer, I will bet it is G.
RVs can have very different issues with wifi. I know that at one time our 5er was strange in that we could make phone calls from one end on the bed only. No other place. With 2 RVs at play, that could be a third issue.
Last, as someone posted, YouTube is notorious for having download problems just by itself. A search on the net will give you many suggestions on ways to solve this. Some might even work.
