I thought I'ed repost this message in this thread as well
Glen,
I get an average in my 2010 Tahoe, 17/18 MPg with combination of highway and city.
I live in a hilly city, so I can hardly start the car without having the engine kick in. and lots of stop and go on a slightly uphill streets. and short distances
IT can easily drop to 15 MPg if I only do city driving.
As for highway, I can get it up to 22 MPG on straight flat highway long trips.
I do drive it very carefuly, keeping my eye on Inst Econ DIC, and try to stay in V4 or Autostop most of the time. but somtimes you would hold the traffic behind you, so you woud need to give it a kick into V8.specially on an slight uphill road.
Yes, One has to drive it very very carefully in order to get higher mileage specially in my city.(at least in my case)
I often wonder if I drive a regular car that carefully, I bet I would get a much higher mileage as well
but overall I am very happy with my Tahoe, although I am unable to get the 22MPG city rating with it

 

I'm in the Irvine/NewPort Beach area in Orange County California.

I know there is a GMC/Cadillac dealer down here I haven't talked with yet.

 

I'ts not very hilly around here - but Irvine seems to have the city traffic arranged so that you can't go 2 blocks without a long red light. Although the hybrid is supposed to deal with stop/start fairly well - I am not sure the battery has had a chance to really charge up. I am trying to get some longer drives in.

 

When I first got it. I babied it and got 20 mpg.

But got tired of driving it that way and drove it normally and averaged 17-18 mpg.

 

I took my first reasonably long drives with it recently - each trip around 100 to 150 miles roundtrip. I averaged about 23.5 mpg - which is pretty good considering one leg was stop/start for about 2 hours. I found if I can stay in the 65-70 mph range I can do even better - however it is hard to drive 65 on the california 405 without becoming an obstruction (unless its rush hour when you can't get much over 30 for long distances).

Once the car warmed up I found I could travel in electric mode for some distance up to about 30.

I am discovering that the electric mode does not seem to kick in until the car is well warmed up.

 

Sounds like the battery pack is getting back into shape after sitting unused. Your engine won't start going into autostop until it is up to operating temp so the catalytic converters are fully lit. The emissions control systems have to be fully operational before it can start the shutdown cycles.

 

I've just taken my Tahoe around the island of Evia in Greece, driving on a lot of dirt tracks up and down steep hills. My wife wanted to visit a number of beautiful, and secluded beaches!
I was down to 10MPG(US) because of all the slow speed work. I kept it in 2WD most of the time, and didn't go down into the manual range. I know from past experience if you put it into one of the manual gears the Tahoe will NOT go into electric mode. Back onto the blacktop i was back getting between 18-19MPG(US).

 

I seem to average 17 city and 18 on the interstate at 85 MPH.

I did a trip this weekend and got 19.5 on the interstate while cruising at 75 MPH.

 

Hi everybody. I am close to 50000 happy miles! I was checking the epa website for fuel economy and got this big surprise! The '11 models are rated 21 city 23 ighway mpg by the epa, my '08 still rated 20/20. Also wondering about how is the Volant performing, I am thinking to get one myself. Check the link for EPA.

http://www.fueleconomy.gov/feg/findacar.htm

 

Actually is 20/23 MPG both 2wd and 4wd Yukon, Tahoe and Escalade Hybrids.