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Chevrolet Suburban and GMC Tahoe MPG - Real World Numbers



  • I've driven a slew of new cars and trucks, and I'm a little OC about checking my milage, miles/fuel purchased. I never believe the trip computer. I consistently get 15+ around town in my 04 Tahoe (5.3V8, 2wd, standard axle) and 18-19-20 hwy depending on speed and road conditions. While those numbers may not qualify as an econo-car, they also do not justify the "gas guzzling" image big GM SUV's have. My x-01-Toyota Sienna promised very high numbers on the window sticker but never did better than high 16's in town and 20/21 hwy. My wife's 04 Lexus RX330 gets high 17's city (no experience on the highway) but that is offset using premium fuel. Dollar for dollar, it costs about the same to run her RX a thousand miles a month as my Chevy. The best kept secret in the auto industry is that GM makes big trucks that get pretty darn good milage. Go figure.
  • jay_24jay_24 Posts: 536
    We also get about 15 mpg in town (slightly less in the winter) and about 18 to 20 on the highway. We have gotten as high as 23 (three tanks in a row) in certain conditions but 19 is the average mpg on the highway. When we tow the camper and have 4 bikes on top the MPG drops to 16ish on the highway.

  • Hi all - we are considering purchase of '02-'04 4x4 Suburban and have concerns re: mileage. Salesman last night mentioned different rear axle gear ratios and said that there were 2 different options. He said that they would have similar performance on highway but that one was definitely better for in-town. I saw mention of "standard axle" in dardson1's entry (#2 in this thread) so I thought maybe someone here could explain options and benefits of each and give a little insight to a Suburban "newbie". THANKS!!
  • as I understand (even though I do not tow), you need a higher number axle ratio if you plan to do serious towing. A lower number will increase economy in normal driving. I had an 02 Tahoe (3.73 axle) and now have an 04 (3.23 axle). Both had the 5.3 engine and 2wd. I get about a mile per gallon better, city. Of course, that assumes they didn't make other modifications to squeeze a few more drops of gas out of the trucks between 02 and 04. good luck
  • Thanks for info...of course, now I'm even more confused :confuse: than before as the salesman was telling me that the higher ratio gears will get better in-town mileage...upwards of 3-4 mpg improvement. His reasoning was that the lower ratio gears cause the tranny to downshift more often when going up slight inclines and that the downshifting then causes the engine to work a little harder and hence the gas mileage goes down. What kind of mpg numbers are you getting with your '04? Any others out there care to share numbers too? Thanks!!
  • Looking for someone who's purchased an aftermarket overdrive for their Suburban or Tahoe. I'm looking at a GearVendor unit that promises a 20% improvement in MPG. Based on the MPG saving and my annual miles plus $3 a gallon gas, the unit should pay for itself in 6 years. I have a 3/4 ton 4wd with a 6.0L and 4.10 differential ratios. Current MPG is 13.0 for a 80% city 20% highway mix or 14.8 to 16.0 MPG straight highway depending on driving speed (really drops off above 65 MPH).
  • wynotwynot Posts: 1
    Gotta be careful when saying higher and lower ratio, because the effect is reverse of the terminology.

    In general, if you have a lower ratio rear end (3.73 or 4.10), you will have better acceleration, a higher tow rating, and possibly lower fuel mileage. A higher ratio (e.g., 3.23) gives, in general, slower acceleration, lower tow rating, and higher 'highway' mileage. And most likely, downshifts won't occur as often with the 3.73 or 4.10.

    Now, if that makes things straightforward, let me throw mud on it. GM makes a 4.8 and a 5.3 V-8 for the Tahoe (or used to). Most people who have bought the 4.8 did so for gas mileage, yet most people who have the 5.3 get better mileage. Real world says that people develop an expectation of performance and mash the gas pedal until they get it. So as a result, most people work the 4.8 to death and pay for it at the pump.

    I suspect that if you coupled a 4.8 with a 4.10 or 3.73 and matched it with a 5.3 with a 3.23, the gas mileage and performance would be comparable. I tow with a 5.3 and a 3.73, but if I move to the fifth wheel, I would go for the 5.3 and a 4.10 because it would get better gas mileage and provide better performance (engine wouldn't be working as hard).

    Additionally, most engines have a sweet spot for fuel economy. My Tahoe gets worse mileage at 55 towing (about 15), then it does at 60 or 65 (about 16-16.5). On the highway, no trailer, at 65 mph, I get over 20 mpg, but I can get 13 with a lot of in town driving.
  • dardson1dardson1 Posts: 696
    Had an 02 with 5.3 2wd and 3.73 axle and it got mid to high 14's. Had an 04 5.3 2wd w/3.23 axle and got low to mid 15's. New 06 5.3 2wd w/3.23 axle first three tanks is getting close to 16. This is all mostly city with 15-20% freeway. I drive fairly conservatively. I could likely lower those numbers 2mpg by driving it hard. Can hardly believe they can squeaze this kinda milage from a beefy V8. love my Tahoes :)
  • b1pigb1pig Posts: 1
    After we bought our Tahoe, we were driving twice a week to Jacksonville, FL. I put a K&N FIPK and a Flowmaster 40 series on it. The gas mileage improved by an obvious amount. We ended up with about 1/8 a tank more fuel in the tank after the mods than before. The numbers by the tank full hover around 23mpg for us. This is considering that I have a lead foot and thouroughly enjoy the sound of the exhaust. :-) Consider that my '98 Gr Cherokee with 4.56 gears and 33" tires on a 4.0 6cyl gets about 15mpg.
  • I have a question regarding your K&N air intake. Are they as noisy as I’ve heard? I just bought a 2001 Surburban and was about to buy the normal K&N replacement air filter (approx $40). Is it worth the cost difference to buy the intake ($210 on Ebay) and is the noise a nuisance? My wife will drive the vehicle a lot and she’s mentioned that she doesn’t want it sounding loud. While I’m at it, is there a exhaust system that will add performance and not sound too obnoxious. I want it to sound nice and deep, I just don’t want it to be too annoying on long road trips. I’ve heard the Borla setup and liked it. How is that setup? Thanks for all your help, I’m loving my new truck!
  • I have a question regarding your K&N air intake. Are they as noisy as I’ve heard? I just bought a 2001 Surburban and was about to buy the normal K&N replacement air filter (approx $40). Is it worth the cost difference to buy the intake ($210 on Ebay) and is the noise a nuisance? My wife will drive the vehicle a lot and she’s mentioned that she doesn’t want it sounding loud. While I’m at it, is there a exhaust system that will add performance and not sound too obnoxious. I want it to sound nice and deep, I just don’t want it to be too annoying on long road trips. I’ve heard the Borla setup and liked it. How is that setup? Thanks for all your help, I’m loving my new truck!
  • Okay, so it doesn't exactly SIP, but it gets excellent mileage for a big vehicle. I've got 2002 with 5.3l 4x4. Best mpg, totally legit on highway (70mph)was EXACTLY 20.01 mpg. That's 400 mile roundtrip. I've never gotten below 15 mpg. That's better by far than my dad's old Toyota 4-runner, which could never do better than 18 mpg, and about the same as his current Highlander. So go figure is right. I personally get tired of people yammering on about my 'gas guzzler'. I have a friend with BMW suv who gets far worse mpg than my suburban. Yeah, go figure. Oh, and I often carry seven people in my truck, which equals, oooh, about 140 miles per gallon per person, which is a little better than that smug dude in the Prius. ;)
  • dardson1dardson1 Posts: 696
    you are so right. . . the best kept secret in the auto industry is the respectable milage GM squeazes outta their large vehicles. For reasons I don't understand Toyota/Lexus (I've owned both) get fine EPA numbers that never come close to reality. :confuse:
  • Local: About 15 - 16 mpg
    Highway: 16 - 19 mpg (16-17 mpg with average speed of 65-75 mph and upwards of 18-19 mpg with average speeds of 55-65 mph
  • Just bought it, one owner (doctor) with 96k. Its a 5.7L with K&N Air System, Edelbrock Headers into Flowmaster 40 other than that bone stock, and I got 20.5 :shades: mpg on the first tank I put through it. 75% highway, 25% city involved. I am very pleased. This truck was clearly very well taken care of, and rides like a dream
  • Hi, I hope this is posted in the right section!

    Has anyone tried an after market "Mass Ait Flow Sensor" for better mileage? Such as the Granatelli Calibrated Mass Airflow Sensor?

    I have a 99 Tahoe (Old School).


    BTW, I get a terrible 10MPG
  • I have a 2001 LT with Z71 Wheels/Tires. I don't know the definition of city driving but driving in New York City I get 13MPG. The best I ever got on the highway was 16.2MPGand this at speeds of 65MPH-70MPH. Some say they get 18-19MPG and more. How? What changes did you guys make that really improved MPG. I read about the amount of oil in the engine and the crankshaft position sensor. I'll try this one next.
  • jay_24jay_24 Posts: 536
    13mpg in new york city would be expected, guessing you spend a good amount of time just at idle.
    For highway we always get 18 to 19+. But its a trip of 350 miles at 65 to 70mph. Maybe one stop for a potty break for the kids. Otherwise constant speed, a few hills, no mountains.

    If I take our Tahoe to work, I spend 20miles at 65mph (interstate) and 8 miles of city or stop/go traffic. Then I get about 16.

    long constant cruising it the key to the better milage. Also check the tire pressure. I think 32 is recomened, I have ours at 34.
  • p100p100 Posts: 1,116
    Actually, 3.73:1 or 4.10:1 are higher ratios, but synonymous with "lower gearing." 4.10:1 gear ratio means that 4.10 turns of the propeller shaft will produce one full wheel revolution.

    A 3.23:1 would be a lower ratio gearing, but synonymous with "higher gearing".

    So in summary, the higher the ratio, the "lower" the gears
    and vice versa. A high ratio gearing (low gears) is always good for heavy towing, but you pay a fuel penalty when not towing.
  • p100p100 Posts: 1,116
    The secret is pretty simple. GM torque management system assures that engines run in the top gear at very low RPM. Once you increse the RPMs, the fuel economy drastically decreases.
  • dardson1dardson1 Posts: 696
    gotta agree although I'm not sure of the science. Seems to me these big engines reward you with pretty darn good MPG when driven carefully vs. not so good MPG when driven hard. I'm old enough to feel no need to show off. Knowing I can go if I want to is enough for me. I rarely downshift, keep near the limit driving the mile or so between stop lights, and never sit idling in a drive-up. I consistently get 15+ MPG in my local driving. I intentionally drove one tank like I was a kid, again. The milage dropped into the mid 13's which ain't bad all things considered. My old Expedition on it's best day couldn't get better than 12+. love my Tahoe.
  • mm450excmm450exc Posts: 37
    Got a 2001 Tahoe 5.3 4x4. Had error code P1133 I think it was come up. Changed both oxygen Bank1/2 sensor 1. Got the Bosch sensors. Driving on the highway doing an average of 65MPH I got 23.1MPG. I was shocked!!! Let's see if I can do this again. :)
  • rockman59rockman59 Posts: 250
    I have a 2006 Suburban 4 x 4 that consistantly gets 22 mpg at 65mph....and 23 mpg at 60mph. I get around 18mpg in town. I stay away from those stop light drag races and drive sensibly. Seems to work for best gas mileage.
  • nosbor77nosbor77 Posts: 40
    Have any of you noticed a difference in gas mileage as a new engine is broken in?? Chevy is telling me I should see improvements at about 8-9k miles. Just wondering. It wouldn't surprise me if they tell people this just to get them to shut up..
  • 73shark73shark Posts: 325
    I have an 07 LTZ and the MPG is actually getting worse. Don't have any hiway mileage yet and only have about 1,000 miles on it but it's gone from about 15 down to under 12. (and that's doing the grandpa thing) When I take it in to get all of the little niggly things fixed, this subject will come up. The only time it goes into V4 mode is when it's coasting or going downhill. The one I test drove would stay in V4 mode on level road at 35-40 mph. Something's wrong! :mad:
  • magnitudemagnitude Posts: 8
    Took delivery of my '07 LT3 on Saturday. After first fill up, mpg is about 15.8, with mostly highway driving, but also stop and go mixed in. My goal is to get close to what my '02 Trailblazer was getting (16.8) and I'm pretty optimistic.

    I'll have a good idea at the end of this week after going back and forth to work (90 mi. round trip).
  • togadelictogadelic Posts: 21
    are the 07's really getting out there?
  • oniscusoniscus Posts: 10
    factory ordered mine and got it 2 weeks ago and I love it, 07 5.3L 4x4 LT3. So far my counter reads 16.8MPG, that's mix driving, but mostly city. (Phila)
  • sojoratsojorat Posts: 3
    I have 07 LT2 with 3rd row. I am getting 13 mpg with 70% highway driving. I called GM about this and they said all I could do was bring it back and have it tested. I thought i was going to get around 16-17 mpg when i bought it. So i am paying 25% more per month in gas than i thought. This cost me over $50 a month. If anyone is getting better than 13 mpg please tell me what you are doing. :sick:
  • nickhejnanickhejna Posts: 3
    I've heard that the 07's need time to " break in" to motor and computer program in order to maximize gas mileage. Has anyone else been getting horrible gas mileage. I drive easy, mostly on the highway and im getting like 14 mpg. My brother works at the dealership- he says the GMC rep. said give it about 3000 miles to break in. Anyone else have any info on gas mileage on these new engines?
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