Chevy Silverado and GMC Sierra Real World MPG Numbers



  • string2string2 Member Posts: 71
    OVERALL mpg is showing 15mpg. I get 12 to 14 city...depending. This takes in the very short around town trips and the 20mpg I get on the highway.

    Speeds above 70mph will net 17.5 to 18.5 w/o active fuel management coming on.

    Hi Chuck1
    I sure would like to get 18.5 miles on the highway without AFM. Especially if (at some future time) it would, miraculouslyly, begin to start activating the AFM at higher speeds.
    My AFM, at low mileage, works okay up to about 52 MPH then drops off quickly. Past 52 it just activates for very short distances on level highway, then activates less often up to about 63 MPH. After that, it only works going down hill. I only get 16 MPG w/o AFM driving about 70-73. I get about 15 in town. GM tells me it is operating normally?
  • cabe227cabe227 Member Posts: 2
    Hey String, I just bought my brothers 2011 Silverado 1500 CC 4x4 5.3L flex fuel. Truck has 7,500 miles on it and same thing, active fuel management doesn't switch on unless your going down hill or slowing down. Instant Econ. gage said 12.5 on a 20 mile trip on flat straight highways at 60mph Burning E-85. Even with 89 Octane it only got 14 at 65-70 highway speed. I bought a superchips programmer and am anxious to see if a fuel map has more than a 2MPG difference. It is rocking 33s with the factory 20" rims. Wondering if you ever pinpointed the issue???
  • string2string2 Member Posts: 71
    Hi Cabe227,
    Doesn't that really hack you off! No, I haven't found the problem yet. And since there is no trouble code, I'm stuck. I've been considering getting an aftermarket program fix, but I keep hoping it might correct itself, but I'm pretty sure that's not going to happen.
    I prepared a letter earlier this month, outlining all the poor gas mileage & Active Fuel Management problems i'm having with my truck and sent it CERTIFIED Mail to BILL SUESSMAN, who is the General Manager of Ron Craft Chevrolet in Baytown, Texas. I've gotten no response. He has ignored my letter.
    Please let me know if your programmer worked for you! My overall mileage right now shows 14.7 MPG. I drive about 60% at 60 - 70 MPH. MY Active Fuel Management system rarely works at that speed, except when going down hill.

    Someone else may have previously found out what the fix is to this problem and will respond on this post, I hope
  • cabe227cabe227 Member Posts: 2
    I reset my average MPG meter and drove about 100 miles 15 in town the rest on a 55 MPH highway. running E85 I'm only getting 10.7MPG. I'm planning a trip to the east coast (~1000 miles) and plan on switching to 87 or 89 octane. I hope the superchips Cortex computer can help me get atleast 15 MPG. Im thinking that our trucks are just a bad batch and there isnt enough of them out there for a recall. With the 3.42 gearing and 6-speed transmission and the 5.3 motor we should be getting 18 or better. My 2005 GMC had 4.10 gears and a 5 speed OD tranny with the 5.3 and it got 18+ hwy with 33" tires. Anyway, the computer will be here this week so ill be sure to post results, E 85 and 87-91
  • chuck1chuck1 Member Posts: 1,405
    E85 will net you lower mpg. I get 12 to 14 on 87 around town. So the 10ish on E85 doesn't sound outlandish.
  • jcmoore2jcmoore2 Member Posts: 7
    If it helps. I have an 02 Z71 with the 5.3 and 3.73s. It has 79000 miles on it. I drive it 25 miles to work w/8 trafic lights and 3 stop signs. I upgraded the truck with a K&N system and a Flow Master cat back. I get 17-18 mpg around town and 18-19 mpg on highway (w/east coast hills). I have found it gives me a lot more bottom end power also. Big key I have found over the years is More air in and out helps alot. Gota let the truck breath.
  • string2string2 Member Posts: 71
    Hi icmoore2,
    Does the K&N System have anything to do with changing the computer programming that might void the warranty? Is this system one that you order and put on yourself or is it something you need to have installed?
    What kind of gas mileage were you getting before you upgraded to the K&N system?
  • solerisoleri Member Posts: 4
    Come on guys, all you silverado owners need to quit lying to yourselfs. I accepted & came to terms with the mpg my Truck gets. Here's the figures driving it like theres an ege between the gas pedal & the floor. 11 city 16 hwy at 70 mph. This is horrific! I thought something was wrong till I talked to a Co. worker that had same truck. SAME MPG numbers. And dont go by that dumb computer on the dash. Chevy just put that there to make us feel better. Calculate at the pump. "miles driven divided by gallons of gas used". Only way to get tru figures. Im going back to my 86 toyota 4 banger. Never let me down and get 23 on the hwy all day long, and is a lot funner & easier to work on. And can actually hold its own off road. Accept what you get, you'll feel better after. Id sell while you still can before gas goes up anymore. Mines worth less than half of what I paid for it after only 55,000 miles. Just my 2 cents worth guys.
  • chuck1chuck1 Member Posts: 1,405
    "16 hwy at 70 mph"

    This is much less than others. Couple of questions-

    Did you add bigger tires?
    Do you have a lift?
    Do you have a CAI?
  • ttaupier1ttaupier1 Member Posts: 50
    Hi String, I have a GMC sierra 2003, SLT, 17 in Denali take offs wheels, 32.5 Yokohama ( M&S), "NO LIFT" ...I run mobile 1 synth in tranny, and diffs (expensive tranny fluid). I have a KN FIPK, and stock exhaust, I have a 300# bed cover-fiber glass and painted. Tire pressure I maintain about 35# every tire. My best all around mileage is about 17.9, ....if I spend 80% on highway .. usually around 18.7mpg for longer trips ( 60-75mph). If I keep it near 65 mileage goes to 20-21.... this is in the northeast and tons of hills. Long drives on back roads lights or stop signs upper NY 21MPG,

    I also installed an electric fan ( and took the crank shaft weight off motor) FLEXLITE - engine seems much happier starts easier runs smother.. and punch is great at rear wheels.. i have heard 10 % low end HP but have yet to measure rear wheel HP

    exclusively city I'm about 14.5 like jersey city
  • string2string2 Member Posts: 71
    Hi ttaupier1
    When I first posted to you, I didn't notice that your model engine doesn't have Active Fuel Management. But it looks like you are getting mileage as good or better than most with AFM. I'm running a stock 5.3 2011 Silverado Crew cab, 3.42 dif, tires pressure 35 lbs, - 6,300 miles. My average city is about what I expected, about 14.7. However, my average highway mileage is about 16 MPG (almost all level highway). My AFM is not working above about 60 MPH. GM says they would fix it, but they can't get the truck to produce a trouble code to show them what to repair. Otherwise, they say, they have to assume it is working as designed. Do you have any ideas that will get better mileage out of this engine that won't void the rest of my warranty.
  • incognito1949incognito1949 Member Posts: 2
    I bought a 2001 Chevy Silverado Superduty dually last year to pull our 14,000 lb fifth wheel. My husband says it only gets 2 miles to the gallon while towing (gas not diesel) Is there ANY way to improve this performance? It's really hard to imagine any vehicle that only gets 2 miles to the gallon.. But this silverado never misses the opportunity to stop at a gas station. We have an upcoming 900 mile trip one way towing the 5th wheel so I'm looking for some way to maximize the gasoline consumption since prices are entering the stratosphere on gas now.
    Any help appreciated. :cry:
  • chuck1chuck1 Member Posts: 1,405
    There is no such vehicle as a Silverado Superduty. There is an HD version that may be the model you have. Anyway, there is no way physically that vehicle could be using that much gas and not have a check engine light or other indicator coming on. I tow on a regular basis a 5,000 pound travel trailer with my 2011-5.3 Silverado half-ton. On the worst conditions it gets 8.5 towing.

    Pulling a trailer (especially a fifth wheel) and fuel economy does not mix.

    I would suggest looking at the amount of gas (cost) you will use compared to staying in cheap hotels and NOT TOWING and see what pencils out for you.
  • incognito1949incognito1949 Member Posts: 2
    My mistake.. it's just a silverado 3500.. extended cab 2 wheel drive, dual rear. It does get very poor gas mileage but the 900 mile tow is a necessity and can't be helped. Going to MD Anderson Cancer Center and have 4 cats and a dog which are our babies so putting them down or giving them away is not an option and pet friendly hotels are not 'that' friendly. Bill say's the engine light does not come on so I don't know what the problem is. We had a ford f250 diesel before this one and it got lots better mileage but the tornado's of last April destroyed it with a 150 year old oak on top of it. I guess there is nothing to do but suck it up and make the trip..on a wing and a prayer. Thank you for your help. ;)
  • chuck1chuck1 Member Posts: 1,405
    Yes, Diesels get better mpg when towing. They don't need to "rev" as high to get torque for pulling power.

    I really don't think you have an issue, except your using a gas truck to pull a fifth wheel. My guess is 99.5% of 5th wheels are pulled by diesels.
  • unskinatorunskinator Member Posts: 9
    well if u talking imperial gallons then your mileage is not that good because compared to US gallon which is 3.78 liters the imperial gallon is 4.54 liters. So that would lower your MPG figures about 20%. I dont trust those in dash MPG thinks. Best is still to calculate with the miles u driven and actual gas u put in your tank. Smile life is short.
  • solerisoleri Member Posts: 4
    My truck is all stock except Mufflers. I just started doing only 60 on the HWY and only went up to 17.3. I asked my co-worker with same truck to try this speed as well. Came back with 18 mpg. Both of our trucks our the same. Anyways I have now traded it in for a nissan frontier with 2wd V6. Still tows a lot but I now get 24 mpg. Much better and saved a lot off $$$ just in the first week of driving.
  • obyoneobyone Member Posts: 7,841
    You're comparing an 8 year old full size truck vs a new pint sized truck. I would hope that the mileage would be better. Not so sure on the money being saved as the Chevy was paid off and now you've got monthly payments. Takes a lot of gas to make up for that monthly.
  • solerisoleri Member Posts: 4
    Well I did trade it for an 2006 Frontier Crew cab, so the trade was close to being straight up. I just wanted out of the truck before gas went up to $5 this summer and nobody will buy or trade a big truck after that. However, the frontier does not seem smaller. Parked next to my truck at the dealer there wasnt much of a size difference. And the Nissan can tow 6000 pounds still. When I towed my 4500 pound camper with my 5.3 Silverado I only got 7 MPG. Im sure I will do much better now. Anyways, good luck to guys and thanks for the input.
  • chuck1chuck1 Member Posts: 1,405
    edited March 2012
    It always amazes me when someone trades a car/truck for gas mpg. The truth of the matter is, if you put pen to paper-as one poster said above it will takes years to come out ahead. You must factor in depreciation, sales tax,tags, higher insurance etc. and it will take along time to come out ahead.

    The only time it really makes sense is when you are having monthly repairs that equal a payment, or the vehicle is becoming so unreliable you can't trust it. Then it makes sense.

    Usually there is an underlying reason for the purchase that excludes the above.

    I get between 9 and 10 towing a 5,000 pound 28 foot travel trailer. RVing is a luxury, one can always stay home.
  • wgw100wgw100 Member Posts: 1
    Apparently I'm fortunate driving an '05 Silverado 1500 extended cab 5.3L with 3.73 rear gears, 4L60E tranny and 2wd. I get 11-12 MPG pulling a Lite 28 ft 5th wheel that hits the scale at 6400 lbs loaded with only propane, about 5 gal water and gray and black tanks empty when traveling. I added a long leaf from a 2500 spring set to the rear springs and the biggest tranny fluid cooler I could find. I considered a 2500HD, but at nearly 1,000 pounds heavier and 8 to 9 mpg...maybe 10, decided to beef up the 1500 with intake, exhaust and ECU chip and see how it goes.
  • kmt3kmt3 Member Posts: 2
    Its not wierd but simple physics which is a body in motion tends to stay in motion.with no air drag all you have to do is get the weight moving and milage should be about the same after.slowing your speed results in better mpg.
  • 99avalon99avalon Member Posts: 4
    I would be skeptical myself were I reading what I'm about to post. We bought an '05 Chevrolet Suburban 1500 2wd 5.3 auto LS w/118K miles out of Nevada, one year ago. Been keeping track of the mileage. It has exceeded my expectations. Everything I'm about to describe is verified with the onboard computer AND manual calculations. If we burn through a tank of JUST around town driving, it'll be 15-18mpg. Worst yet being 15mpg. Driving up 1-15 from Springville to Centerville at 70 mph (cruise control, family on board, A/C on) it consistently gets 23+ mpg. At 75mph it gets 22-23 mpg. Our last trip to Arizona, 10 hours, we drove all night, cruise set at 70mph, heater on, all loaded up for vacation, averaged 21.5 mpg. Best yet? I drove with my two boys from Springville, to Rocky Mountain Raceway, back to Springville. Goal was to get best MPG possible. Topped off when we left, drove nicely, cruise set at 60mph whole time, filled up when we got back after 114 miles (verified with google maps). Onboard computer said 27.5 mpg! I didn't believe it, but when I filled up it only took 4.12 gallons, full to the brim. (not recommended) You do the math, 114 miles with 4.12 gallons. All stock truck. Tires = Michelin LTX MS2 245/75 R16
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