I have a Nissan Rogue and it looses power.
I went to Las Vegas last week and every time I hit a hill, I was doing about 75-80 the
power would drop down to around 30 even if I had it floored....
Sounds like it is leaning out, could be a plugged fuel filter or a weak fuel pump. A system pressure and flow test should tell you.
When you are going up a hill and depends on how steep the hill is you are supposed to change transmission into another gear I forget of the top of my head what gear that is but you can look at your owners manual and it will tell you what gear it should be in going up hills. If no owners manual just Google owners manual and the year, make and model of your vehicle and it will take you to a site that will show you your owners manual.
Search Nissan Rogue Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Nissan Rogue Experts