Last post on Feb 09, 2011 at 6:32 PM
You are in the Chevrolet Suburban & Tahoe
What is this discussion about?
Chevrolet Tahoe, GMC Yukon, SUV
#1621 of 3150 Re: Help, MPG sucks [jmaynard]
Aug 14, 2006 (8:25 am)
There's nothing wrong with your Tahoe. There's just something wrong with Chevy's sales tactics. Most of their sales force don't know what thier fuel management does. If you apply gas, it will run in V8 mode. When you let your foot off the gas, it drops into v4 mode. Very misleading from their advertising. I say it's false and a joke. I've never been concerned about my mileage when I'm not applying gas. I doubt anybody else is. It will probably save you fractions in mileage compared to before.
Your milage is normal. I was getting around 13.8 when I bought mine. Up until 3000 miles, the best i saw on highway were 19 at optimal spds like 60mph. Also, you have to BABY it to get good gas numbers. No driving over 2000 rpms. Also, most areas are using 10% ethanol in gas. This will result in worse milage b/c ethanol has fewer BTUs. ie less efficient just burns cleaner. The axle ratio you have could make a diff too. Not sure.. The mileage I reported above in my last posting was new to me. It improved when I hit 3000 miles. These #s are only obtainable when criusing on flat road. Don't expect them around town. Basically meaning stop and go driving. Expect your 13.8 or less around town. Yep, I'm impressed by the mileage I get on hwy. But they should be forced to get on TV and explain to everyone that their fuel managment system is a joke. When I didn't see it come on during the test drive, I was told that I had to drive it longer on the hwy to see it come on. HA.. that man should be fired.
#1622 of 3150 Re: Help, MPG sucks [nosbor77]
Aug 14, 2006 (1:10 pm)
Thanks for the insight. I too was fooled, not only ny the advertising but by the mass amounts of litrature that are published on the subject of this technology. It clearly states that the V8 running at a steady speed is only utilizing about 15% of it's available power and that in V4 mode it wold be about 80% utilized. Now, that would indicate that in V4 mode 10-15% more power would be available which would be more than enough to support the vehicle during highway non-steep incline driving. My experience is that it only goes into V4 in a decelleration mode. ANY eccelleration, even attempting to hold a steady speed on flat road or downhill results in V8 mode enabled. This just does not seem right. I am going to take the vehichel to the dealer and get them to show me how this system interacts with the vehicle. If someone programmed it, it can be fixed. It is just a matter of getting to the correct person. I'll let you know if I have an success.
#1623 of 3150 Re: Help, MPG sucks [jmaynard]
Aug 14, 2006 (3:40 pm)
What gear are you running, 3:73 or 4:10 - I have found that I need to run 2400 RPM or better to activate the V-4 mode on level or slight up-hill conditions, I can accomplish this by either fooling the truck using the tow mode, or exceeding 75 - 80 MPH, at these speeds I am not saving anything, but it does run in V-4 mode, even up-hill. I am tying to prove that the 4:10 gear is a better choice, it seams that the drivers who opted for the 4:10 choice are reporting better MPG. thanks George
#1624 of 3150 Re: Help, MPG sucks [junglegeorge]
Aug 14, 2006 (4:14 pm)
I don't remember from the sticker. I believe the 3:73. I am a little careful topping the 80 mark as the truck is still under 500 miles and the police just don't seem to understand
I suspect that if you can 'fool' it then it can be tuned or reprogrammed. After I get to the dealership, I suspect I already know their answer, I will report back here. I am willing to be the squeeky wheel, but if I do have to go the GM route it I will need the support of a lot of other drivers. I have found through other venues that grass roots movements against big companies DO work. If we can garner enough support e CAN grab media attention and get the numbers that were promised to us.
After I get back from the dealership I will make my private email address available to everyone to see how much support we really have.
#1625 of 3150 Re: Help, MPG sucks [jmaynard]
Aug 14, 2006 (4:46 pm)
Show them a copy of this which clearly states "In situations where extra power is not needed, such as cruising down the highway on level roads, Active Fuel Management deactivates four of the eight cylinders with seamless precision."
#1626 of 3150 Re: Help, MPG sucks [73shark]
Aug 14, 2006 (5:22 pm)
I suppose that 'level' is relative. For me - is level, for Gm it appears that \ is level.
#1627 of 3150 Re: Help, MPG sucks [jmaynard]
Aug 14, 2006 (6:57 pm)
Your computer should be able to be reprogrammed. This is from the GM advertising regarding 4/8 engines:
"The powerful 32-bit engine control computer triggers cylinder deactivation based on inputs from vehicle sensors ómaking deactivation virtually undetectable." Either the sensors are sending the wrong info or the programming is not correct for info being fed in.
There are a lot of complaints coming in from all over the country on this matter. GM better stand up and take care of business on ths one.
#1628 of 3150 Re: Help, MPG sucks [jmaynard]
Aug 14, 2006 (8:59 pm)
I, too, am disappointed in my gas mileage. I have not reset the DIC computer and am getting 13.2 mpg. However, I love my new Tahoe. Having had the first generation 4 door Tahoe (a '96), a 2000 (when they updated the body), a 2003 (Z71 model) and now my awesome 07, I see great improvements - both mechanically and asthetically. When it comes right down to it, I bought it because of the new body style, features and size. It's the perfect size for my family. Sure, I could have bought the Expedition, but I didn't want a Ford product. I have had wonderful luck with all my Tahoes and please, don't you just feel COOL when you're cruising down the road? I truly am sorry for all who bought for the gas mileage and are not getting the gas mileage advertised but this is a large vehicle with a lot of horsepower. I didn't buy if for the fuel efficency - if I did, I'd have waited for the hybrid. I just love the look, feel and dependability of my new Tahoe. That's gotta be good for something...
#1629 of 3150 Re: Help, MPG sucks [tony20fan]
Aug 15, 2006 (6:22 am)
I WAS waiting for the hybrid, until Gm decided to pull it in favor of this Active Fuel Management. This is also my 3rd Tahoe and by far the best ride, most comfortable and coolest body style of any of the previous ones. My first one, a 1999 2 door version, was really sharp for it's time.
I specifically justified the ability to upgrade based on the fuel savings. At almost 3.00 per gallon every MPG counts. If GM advertises that they can make this easier on me by running this beefy V8 on just 4 cylinders during cruising then I expect them to live up to that promise. It's all about getting what they sold me.
If I sold you a ticket to Rio and when the plane landed you were in Alaska wouldn't you be upset. Sure, both areas have outstanding beauty and are really nice vacation spots, but you paid for a beach vacation not a glacier one. I want my beach vacation, and so should everyone else.
#1630 of 3150 Re: Help, MPG sucks [jmaynard]
Aug 15, 2006 (7:04 am)
OK, you got me. I wouldn't want to go to Alaska if I was planning on Rio - and I wouldn't have packed the right clothes!! Good analogy. I guess I am just resigned to the fact that I'm not going to get better gas mileage and there's not much I can do about it. GM won't. True, it's disappointing but I think the best thing I can do is enjoy the car and hope gas prices drop. Oh, and hope I didn't jinx the reliability by actually voicing my satisfaction. That'd be just my luck...