Driving on the highway seems like I'm stressing the car

[xtremesniper]

Hey guys, just a quick question about highway driving.

When I'm driving on the highway, it's pretty normal for me to be going 120KM/h steady for fairly long periods of time. Sometimes when going downhill, this number might go up to 130KM/h or even sometimes (though not too often) 140KM/h.

I notice that the engine gets pretty loud at these speeds, and sounds like it's running at a pretty high rev. Sure enough, taking a look at the tach tells me that it's running anywhere between 3000-3500 rpms, constant.

Is it safe to be stressing the car out like this on a daily basis? (going to and from work).