OK so I have posted a few times and have a few questions. I mainly want opinions to see if my Tahoe Hybrid is malfunctioning.

I changed from the 18" wheels to 20" chrome but my mileage had never been over 18.5. even with the 18". I have problems staying in V4 mode if there is any kind of incline at all. I have tried cruise technique as well as not using the cruise and nothing helps. It seems to just happen over 60mph. I have taken several trips over 200 miles and just cant get the mileage i thought i would get. Again, the wheels didnt change the mileage for me, so I assume is how im driving it or something is wrong with it. Can you veterns of the boards let me know what your technique is so I can try to get some good use of this great vehicle. I am so frustrated I was going to do the unthinkable and trade it back in. Also, what grade of gas are you all using?

I an open to any and all suggestions. I can do really well in town, its the long trips that suck mileage. This is the reason I bought it, the interstate driving!!!

Thanks guys!!!

 

I've had to change my driving style to try and make the most of the hybrid characteristics. I'm always keeping an eye on the instant mpg figure in the DIC, and the Economy gauge.
I've learnt that as long as you don't go out of the solid green zone to the left and right you'll get a respectable mileage. Flooring it, or breaking very sharply doesn't help. Getting into that elusive V4 mode takes a bit of getting used to. Generally i get to the required speed, and then ever so slightly take me foot off the pedal, trying not to loose revs. This is usually enough to get me into V4. Keeping it there really means looking ahead well ahead when driving, and taking account of the terrain adding a little extra gas when you see a slight rise.. but not too quickly so as to keep in V4. If you wait until the rise itself, you'll easily go back into V8 mode.
I find that the change between the two can be very delicate. I may have to start driving in my slippers or bare feet again.. to try and get a better feel on the pedals.
The best I have ever managed was 11.3lt/100km which is the equivalent of about 21mpg US. On that occasion i wasn't traveling very fast - no more than 60. I usually like to go a bit faster than that, and then I get on a long run closer to 12lt/100km or 19.6mpg (US).

 

Same expreince as Rob here in my 2010 Tahoe in terms of light foot gas pedal driving, switchign between V4-V8.
although I managed to get 10l/100km (23mpg) on a 450 miles trip all highway avg speed 65mpg.
my city dirving is not even close to that, although I drive it very carefully. I managed to bring it up to 13-13.5 l/100km ( 17.5-18 mpg)

Rob, what are you avging in city driving in greece?

 

Buck: if a 4X4 are you in 2 High or 4 Auto? ~ 1 mpg to stay in 4 Auto. Next tire pressure? I run at the maximum on the side wall. It's bumpy but I'm averaging 19.7 now that it has warmed up to 35F. And I'm using remote start still.

Long trips? What roads? How bumpy? How fast?

Rob's comments about the "green" zone are right on.

 

I have been in 4 auto and using the reccomended tire pressure. I use auto start in the morning because its been cold and I drive 20 mintues to work everyday. i go through town in auto off which saves but it has to be warmed up first.

I can take 2 ways to work, rural roads or interstate. i take rural because i get better mileage going under 60.

i usually travel on the weekends with the trips around 200 miles each way. The roads are hilly but nothing major and I dont go over 70.

i can do the green zone, but could probably use more practice on the braking part of it.

my problem is on the interstate. on these trip my mileage sucks and it only equals out from me drviving in town during the week. shouldnt it be the opposite? Do I just need to work on not using the cruise so much and try to keep it in V4 mode myself?

 

Buck,
when using my cruise control on my highway trip, I ended up using more gas, and my avg dropped from 10l/100km(23mpg) to 11//100 km 21..4mpg)
Yes cruise control use more gas for sure, since it tries to maintain the speed no matter what the roads are. when driving manually, you can maintain the V4 for much longer, and you can push a bit harder befor an uphill, and release your foot once you reach the top of the hill, to get back into V4 again.
in Cruise it stayed in V8 most of the time, unless I was going downhill. of course you will have to compromise on the avg speed you are driving.

 

Thanks for the update Buck. I have a similar but 41 mile (one way) drive to work. The Remote Start in the morning is costing me about 0.25 mpg based on my longer commute.

If I bypass the 9 mile stretch of I-75 I can get a little better on the 45 mph roads.

The 4 Auto keeps several front drive components spinning and ready for the transfercase clutch. It is a great feature but it steals some of your FE. ~1 mpg is my best guess. In 4 Auto, the faster you go the more fuel that spinning front drive shaft and forward gear set costs you.

I rarely use the Auto. 2WD or 4WD because of the fuel hit.


If your snow is gone set for 2 WD high and give it a few days to average out.

 

2wd or 4h or 4l only. I have also been told by a very trusted GM source that 4 auto should be avoided unless absolutely needed as it can cause excessive trans wear and damage.

 

speed is also a factor in getting the best mileage. 60-65mph gets the best mileage so far. 72-75mph, mileage on 4auto is 19mpg. 2wd, at 60-65mph, the mileage is as posted=20-21mpg. cruise is okay esp if you only driving it at 60-65mph. I will be driving to CT this week and should see an average mileage. btw, I use premium only.

 

I have also seen a marked difference between 2WD, and AUTO. I try and keep in 2WD as much as possible, and only us 4WD when the weather or road conditions warrant.
When on the motorway my best fuel consumption is keeping at about 120Kph - a little over 70mph. Any faster and I can see the instant fuel economy going up to 14l/100km or more.