I have a 2015 Trailhawk, it starts out in 2nd gear too. I do get into 9th gear at 60 mph cruising on a flat or downhill road. When traveling the other direction on that road, which than is uphill, the best I see is 8th gear.
The reason the Trailhawk doesn't use 1st gear is because it has a lower gear ratio than the other renegades. It uses 1st gear when in rock crawling 4 wheel drive mode, that how they get a 20:1 low range rock crawl mode. The other Renegades don't have rock mode, as far as I know and read, and they have a higher gear ratio so they utilize 1st gear during normal driving.
The reason the Trailhawk doesn't use 1st gear is because it has a lower gear ratio than the other renegades. It uses 1st gear when in rock crawling 4 wheel drive mode, that how they get a 20:1 low range rock crawl mode. The other Renegades don't have rock mode, as far as I know and read, and they have a higher gear ratio so they utilize 1st gear during normal driving.