Cruise control doesn't work well if at all down hill. Tried Asking GM customer service VIA the phone about it. But the problem with this is, they just do not know and try to read the owners manual to you, Their is no information on how it works or even if it works in the owners manual. They are providing this support from their centers around World.. (One insisted Hydromantic meant Hybrid transmission). My Dodge manual - states clearly + or - 2 MPH down hill. I took it in to my dealer and said it doesnt hold on any hill I drive (unlike all my other vehicles. They said they can't fix it as their GM Tec paper states it may work or it may not, depending on the hill, and to down shift.
The ability to use my Cell Phone - Flawlessly through the Blue Tooth - Radio & On star. MPG in town, can't beat it if you live in a city or their is a lot of stop and go traffic. Turn by Turn Navigation. These things are great.
Manual needs to be written by an owner and have knowledgeable phone assistance. Sun Visors are pitiful, Put some real Sun Visors on it like on a 2002 Chev-Avalanch. Truck could be lower for easer entry. Front seats need to be large, lengthen with better lumbar support. Add a working Cruise Control.
Just a quick update on my previous review. First, my problems with dis- engaging brakes and abrupt transmission shifts have been solved. The dealer where my Sierra Hybrid was sourced neglected to update my software. Updating software fixed the brake problem and a faulty transmission pump fixed the gear shifting problem. My Sierra now drives just like a standard Sierra and I'm a huge fan and I can confidently say that I would absolutely recommend this truck.
Gas mileage. Exterior appearance. Simple interior.
GM still needs to work on the electric assist when towing. I've noticed some jerking when using cruise control when going up hills. Nothing serious but not as smooth as a non-Hybrid.
I recently purchased a 2009 Sierra Hybrid, 2WD truck. My initial impression is that this is a great vehicle. I have all of the standard features of a Sierra with gas mileage averaging 21 MPG combined City/Highway. Outstanding! Contrary to Expert reviews, I would not agree with assessments that transitions shifts between electric and gas as seamless. On the contrary, these transitions can be felt-- abruptly in some instances. I also have concerns regarding the transition between regenerative and hydraulic brakes. In some instances, my brakes have actually disengaged momentarily making me feel as though I might roll into the vehicle in front of me. A very uncomfortable feeling.
(1) Gas mileage: outstanding for a truck; (2)Exterior: especially relative to Silverado; (3)Ride: very smooth; (4) Interior Noise: incredibly quiet -- perfect for cell phone conversations.
The disengaging brakes feels like an accident waiting to happen and clearly needs to be resolved. I also believe that more work can be done to smooth transitions between gas and electric. And finally, allow the truck to enter or stay under electric power when going downhill at speeds greater than 30