No, it doesn't hurt it. It puts some stresses on the engine and the transmission. If you feel that the car is straining too much, just back off and let it limp up. Theres a really long 7% grade on the way to WV. I just leave the cruise set at 80 and the car downshifts to keep the speed up. Don't worry about it.
thanx for the info.. im asking because i took my new car up to reno on wednesday night.. a lot of hills to climb.. some big rig have to roll like 5 ta 10 mph up the hill.. and i was doing like 70 ta 75... once again thanx
STEP ON MY IS300 ILL STEP ON YOUR LIFE...