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Chevrolet Suburban and GMC Tahoe MPG - Real World Numbers



  • 17.2 MPG...that's a miracle. Are u employed by GM?
  • No miracle on my '06 Suurban. Always over 16 mpg for town driving...and at 70mph and under it delivers between 21 and 22mpg. I drive carefully, no stoplight drags, keep the tires around 38 psi, have a clean air filter, engine tuned , etc. so it can be done.
  • It can't be done and you're not doin' it. Why did u not answer the question about being employed by GM?

    1.The Suburban weighs 400 lbs. more than the Tahoe. That extra weight increases fuel consumption.

    2.Overinflated tires do not improve fuel economy...but underinlated tires will reduce fuel economy.

    3. Careful driving...yeah well, safe is good...but it does not change the physics of a 6100 lb. load being pushed by a 5.3L gasoline engine.

    4.The air filter element on all Tahoes and Suburbans is an excellent fluted paper element design. It's surface area is designed by GM to be very large and it does not saturate very easy. Because pressure drop is so low and air flow so unrestricted...this is not a determining factor for these two vehicles.

    5.Drag racing from stoplites...we don't do that anymore.

    6.Tuning the 5.3L is limited to very few things that can be be tuned. The on-board computer and sensors accurately control spark timing, air/fuel ratios and monitor valve timing and cam angles. Modern spark plug technology limits the electrode wear on the plug tips so that they last a long time. So what is it that you are tuning?
  • steverstever Posts: 52,683
    Sure it can be done. The 2006 Chevrolet Suburban LS 1500 4dr SUV (5.3L 8cyl 4A) is rated at 14 mpg / 19 mpg by the EPA. (link). 22 mpg for this model is ~115% of the highway estimate.

    I've have lots of tanks better than that percentage. My van gets 17/24 EPA and my lifetime is 21.4. The average (mean?) of 17/24 is 20.5 so I'm getting 104% of the EPA ratings over ~112,000 miles. I'd probably be doing even better if my tires weren't 3 pounds off and if I'd replace the original plugs. :blush:

    steve_, "Hyundai Tucson: MPG - Real World Numbers" #29, 29 Jul 2006 5:04 pm

    I don't really care if you believe anyone here or not so long as you keep it civil. But it's a nice chance for me to give Tides some math to double check. :-)
  • tidestertidester Posts: 10,059
    Since you asked ...

    The average is a little more complicated than just taking the straight average of the two EPA numbers. The issue ultimately is how many gallons it takes to drive a given number of miles.

    I'll just point out that the actual figures depend on how your miles are split between city and highway. Even then there is one more complication: Do we use a DISTANCE based split or a TIME based split?

    E.g., when someone says his/her driving is split 50-50 between city and highway do they mean equal miles traveled on city and highway roads or do they mean the time spent on them is split 50-50? They can give significantly different answers for your "average!"

    In your example, let's assume a 50-50 split between city and highway. These are the results:

    50-50 DISTANCE split: The EPA "average" would be 19.9 mpg and NOT the 20.5 you got using the straight average so you would be doing better than EPA.

    on the other hand ...

    50-50 TIME split: Here we need to know what "city speed" and "highway speed" are. I chose 30 mph for city and 70 mph for highway for your case. The EPA "average" turns out to be 21.36 mpg - which puts you spot on with your 21.4 mpg figure!! (Double exlamations because I was truly surprised by the result even if it may be fortuitous.)

    I think most people probably mean a TIME split when they think about how their driving is divided between city and highway. Driving at twice the speed for the same period of time you cover twice the distance of driving at the slower speed but you don't use twice the gas. This accounts for the discrepency with the DISTANCE and TIME calculations.

    At some point I may post details in my CarSpace for anyone interested. :)

    tidester, host
  • steverstever Posts: 52,683
    Oh, now it's getting fun - I could probably get you some pretty close estimates on pure highway vs interurban distance, just by looking at the frequency of my fill-ups. The 50-50 time would be a real shot in the dark. I may have to send you my spreadsheet. :D

    Rockman59 and Oniscus may have read the old Hybrids and Hypermiling - A Help or a Hazard? discussion and learned a few tricks too. :shades:
  • Why perpetuate a myth? People are not blinded by science or innaccurate EPA/manufacturer estimates anymore. There are just too many folks out here getting the same bad gas mileage from the 5.3L Tahoe for those numbers to be credible. When the legal process comes to fruition...and public testimony...and real world experience is used...GM, EPA and anyone else clinging to inaccurate "estimates" will be proven wrong. How many credibility issues can a major corporation sustain before it destroys itself?

    If 16-21 MPG averages were achievable we would see them. 18.5 MPG...which is the mid-point of that too far from real world numbers to be a simple error. What am I implying? I'm not implying. I'm stating that reality is not 16-21 MPG. Those numbers are wishful thinking for some...and possibly worse for others.
  • My reply to RSpencer: No, I am not am employee of GM and your question was not directed to me originally but to another post. Now then....about the mileage. I don't know how you can tell me what kind of mpg my Suburban is getting. I am the one who puts the fuel in the vehicle, keeps track of the miles, reads the computer, and calculates the mileage. X number of gallons and X number of miles is all that matters. My mileage numbers are almost exactly the same whether using the Suburban computer readout or calculating gallons versus miles by hand. You are entitled to your opinions but don't be sending posts telling me what your version of reality is.
  • steverstever Posts: 52,683
    The EPA is revamping their tests to make them more accurate because of all the complaints. Even so, some of us generally achieve the EPA estimate or better on our cars. I have gas records on three cars dating back to 1989 and I'm close to the EPA numbers on all of them.

    Top 10 Tips for Improving Your Fuel Economy
  • What percentage of this forum's members are actually achieving 18.5 MPG (or higher) in their Tahoe 5.3L? Do you have the curiosity and the interest, as a Host, to ask them to submit this in the form of a non-scientific poll of the contributing members?
  • steverstever Posts: 52,683
    This whole discussion exists to gather member mpg reports. Shouldn't take long to count them up.

    The various Consumer Ratings & Reviews would be another source; many of those owners report (or complain about their mpg).

    Unfortunately many people don't post on forums unless they have a problem, and most people don't keep track of their mileage.

    So, it all boils down to YMMV. :shades:
  • Does it boil down to YMMV? Or does it boil down to allowing the truth to speak for itself? Is 18.5 MPG truthful and reasonable for the product in question...the 5.3L Chevrolet Tahoe? A product performance claim that is not supported by the experience of the public should not stand.
  • tidestertidester Posts: 10,059
    Or does it boil down to allowing the truth to speak for itself?

    The truth isn't exactly black and white but owners have been irked for some time and, as Steve already pointed out, change is happening.

    tidester, host
  • Black and white...

    Why does it take federal legislative action to correct a product performance claim problem? Why has U.S. EPA not changed it's methods of estimating fuel ecomnomy for 21 years? Why did it take a mandate in the U.S. Energy Policy Act of 2005 to effect change in fuel economy estimates?

    Section 774 of EPACT 2005 instructs the EPA to create new fuel economy measurements that more accurately reflect today’s speed limits, city driving conditions and the use of air conditioning and other fuel depleting features.

    Was it reasonable to use 45 miles per hour as the representative highway speed for testing for 21 years?

    Are city driving conditions in Los Angeles representative of most city driving conditions in our country?

    Do we not use A/C to survive the heat and humidity in places like the south half of the U.S.?

    Oh yeah...don't take my word for it.

    From te U.S. Senate Committe on Energy and Natural Resources...

    Chairman's statement:

    “The EPA hasn’t updated fuel economy estimates since 1985. We instructed the EPA to update their fuel economy estimates after hearing from frustrated and disappointed consumers who weren’t getting the mileage from their vehicles that advertisements had led them to expect.

    “I consider this provision in the energy bill one of the most potent consumer protections in the bill. It will literally influence how American consumers spend tens of thousands of dollars. Buying a vehicle is one of the most expensive choices a family will make. With gasoline hovering at $2.50 a gallon, fuel economy estimates play a huge role in that choice. I am pleased that the EPA is moving swiftly to implement this provision in the energy bill.”

    We can make good choices...if we know the truth.
  • tidestertidester Posts: 10,059
    The truth is

    (a) YMMV.

    (b) the EPA system is flawed.

    (c) the EPA system is being ovehauled.

    (d) the EPA is a federal agency and, by definition, requires federal action to implement change.


    (e) we appreciate members reporting their mileage here for comparison and for providing real world experience to those considering the purchase of these vehicles.

    I think we've taken this as far as we can here.

    tidester, host
  • So how will it affect the average buyer? What will the situation be down the road possibly next time that we go to a look at a vehicle? A Tahoe?

    The "guidelines of change" are going to reduce the mileage estimates we read on the window sticker. The guidelines as suggested will make them go down:

    City - 10 - 20 %

    Highway - 5 - 15 %

    If the two percentages on the high side are used for the Tahoe -

    16 - 21 MPG becomes 12.8 - 17.8 MPG

    The mid-point goes from 18.5 MPG to 15.3 MPG. ( Which I personally believe is much closer to the truth.)

    Picture a salesman standing next to two Tahoes...down the road...say ~18 mos. or so. His job is to explain why the 2007 model Tahoe is rated 16-21 MPG...and the exact same model parked next to it in the 2008 model year is now rated 12.8 - 17.8 MPG.
  • tidestertidester Posts: 10,059
    I think this is the discussion you're looking for: MPG Ratings May Drop Under EPA Proposal

    tidester, host
  • Interested in what Consumers Union, a.k.a., Consumer Reports found when they did a random dealer purchase and fuel economy test of a 2002 model year Tahoe, 5.3L, auto trans?

    CITY - 9 MPG

    Overall - 13 MPG

    My wife and I are doin' pretty good at 14.5 MPG O/A.
  • mattgg1mattgg1 Posts: 191
    I stumbled across this forum because it was featured on the Edmunds homepage. I have a few questions for you Tahoe/Suburban owners...

    1) How many of you regularly carry 5 or more people plus a full load of cargo, or regularly tow large trailers/campers/boats/ect.?

    I take note of the big SUV's I see on the roadway, and the vast majority are carrying only the driver, and are not loaded down with cargo or a big trailer. Which begs the question: Why do people need or want these vehicles???

    2)For those complaining about fuel economy, what did you expect from such a vehicle? Does it really matter whether you're averaging 14 MPG instead of 18 MPG?

    14 MPG and 18 MPG are BOTH dismally low fuel economy numbers.
  • steverstever Posts: 52,683
    Why do people need or want these vehicles?

    Maybe for the times you don't see them, when they are pulling a boat, camper or hauling their 4 friends to the deer shack or the mall.

    18's a lot better than 14.
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