A friend of mine was telling me that driving East on I-40 into Flagstaff is a long and steep drive. That I will be down to 35 mph at times. I was also told the same about Grants Pass in I-5 going into...
I drive the I-40 frequently go from Southern California to Lake Havasu, AZ (I think my truck can do it on its own now). There are several passes along the route, but nothing too crazy. The one going in to Needles does has some length to it. If you're going eastbound, you're going down the hill anyways. Pulling the summit the other way, especially in the summer, expect the fan to kick on a few times because it gets toasty out there.