Last post on Mar 27, 2013 at 11:39 AM
You are in the Chevrolet Silverado & GMC Sierra
What is this discussion about?
Chevrolet Silverado 1500, Chevrolet Silverado 2500, Chevrolet Silverado 3500, GMC Sierra 1500, GMC Sierra 2500, GMC Sierra 3500, Fuel Efficiency (MPG), Truck
#135 of 176 NEW 2011 REG CAB 5.3L 4X4 SILVERADO
Mar 19, 2011 (1:44 am)
Just did my 1st tankful of 23 gallons and averaged 17.0 mpg. A mix of highway (going to work) and some 2 mile runs to the store etc. Overrall, I'm "OK" with the results but certainly would hope for closer to 19 on average over time.
I've managed to meet or exceed the posted EPA mileage numbers on my last 5 vehicles. It does take some conscious effort to do that - -drive smooth and not too fast - - but can be done. Will see if I can improve on the 17 over time.
Apr 12, 2011 (5:48 am)
Recent highway trip. 1200 KMs. No towing, nothing aboard but me. Average speed on cruise 120 KPH. MPG = 16.68. Given technology today, Iím very disappointed.
#137 of 176 Re: 08 silverado losing gas mileage [gmcustsvc]
Apr 13, 2011 (6:43 pm)
You reference air filter changes. My 03 GMC manual says to use the air filter monitor and does NOT specify the interval. Typically after 3 years and about 25,000 miles, the air filter monitor still indicates a very good filter, but I just change the filter. So, do I trust the GM monitor or do you recommend a minimum change frequency for the air filter?
BTW my 03 Sierra 2500 HD has always gotten 10-14 MPG and 14 is tough to achieve. It is a 2500HD, 6.0L and has the higher numerical gear ratio, so that doesn't help. My 01 was slightly better as it had a slightly better gear ratio, so I assume this is normal for the 2500 GM gas trucks.
Apr 22, 2011 (3:49 pm)
Quote: Recent highway trip. 1200 KMs. No towing, nothing aboard but me. Average speed on cruise 120 KPH. MPG = 16.68. Given technology today, Iím very disappointed.
Are you kidding? You're cruising along at 120 kph (72 mph) and complaining about 16.66 mpg? I'd say you're doing very well.
Keep your foot out of it and slow down if you want better mileage.
#139 of 176 Re: MPG [inwellington]
Apr 22, 2011 (5:59 pm)
Let me start by saying that I was searching for GM truck mileage improvements and found my way here. I have been a GM guy all of my life but have been severely disappointed with my '07 (45k miles) GMC crew cab, 5.3 w/AFM, 4x4 truck's mileage & problems. The sticker said 14/20 mpg and that was probably in some engineer's better dreams. The absolute best ever checked longhand and not trusting the calculator was 18.6 mpg going down hill on a trip at exactly 60 mph all the way. Any additional throttle would kick in the V8 mode so the AFM is truly worthless for highway cruising. The truck has averaged 13.7 mpg over its life and that is unacceptable since I drive a mixture of city/hwy. I knew this truck was made on Monday morning from day one when the valve train rattled on startup. I also discovered today that the rear ring and pinion gears have extreme play, the leaf springs squeak like a '50 Studebaker, etc, etc. I am considering a trade to something else SOON.....MrM
BTW - Cruising at exactly 2 mph over the speed limit of most interstates is not exactly hauling arse or anything and considering we bought these trucks expecting 20 mpg + or - an mpg or so.........you get my point.
Apr 22, 2011 (8:06 pm)
Mine is a 2010 Sierra Extended with 5.3. I and getting at least 17 mpg and up to 21.5. Now that is Imperial gallon, not US. Ours is a tad bigger.
When I was researching trucks by driving Fords (originally my first choice) and GMCs, I took along my trusty ScanGuage II and plugged it into the computer plug so I could monitor the mileage properly. I dismissed a 2009 5.4 Ford because I had to really nurse it to get 16 mpg. I easily got over 19 with the 2010 Sierra, which I ended up purchasing. So far I am pleased.
I hope you can resolve the lousy mileage you are getting.
I am not certain that a Scanguage is required these days, cuz many vehicles tell you what the instantaneous and average mpg is.
It would be interesting if you could drive a truck of the same year, engine, etc. and see if you get better results.
#141 of 176 2007 Silverado Disappointment
May 02, 2011 (4:03 pm)
I have a 2007 Silverado 4/4, 5.3 L. I bought this truck over both the Dodge Ram and the Toyota Tundra because of the gas mileage - 14 city, 19 highway, 16 combined. After tracking several tanks recently, I'm actually getting closer to 11.8 combined. My tires are properly inflated, my air filter is new, I don't do jack-rabbit starts. Very frustrating - if I thought there was a market for this truck right now (with gas prices being well over $4) I'd sell it and buy any of the other truck - both my previous Dodge Ram 4x4 and the Tundra I test drove before buying the Silverado handled like a sports car in terms of turning radius compared to the Silverado, and had I known I'd not get near the mileage claimed, I'd have bought the Tundra (as the 2007 Rams had a beast-like Hemi that was a gas-sucker even on their sticker).
#142 of 176 Re: 2007 Silverado Disappointment [erybil]
May 03, 2011 (7:37 am)
I wonder if there is any upgrade for the on-board computer that would improve gas mileage?
My driving is exclusively on highways. If I was doing city driving my average might dive to 11 mpg cuz you're on the accelerator all the time. Looking at the instantaneous gas gauge, just touching the accelerator drops it below 10 mpg.
Ford's done a marvelous job with their new engines mpg-wise. It makes me wonder why they didn't do it 5 years ago. It just shows to go you.
Btw, I'm happy to see that Chryco is doing well by making some money! They are working hard and cranking out some good products these days.
#143 of 176 Re: 2007 Silverado Disappointment [inhaliburton]
Jun 01, 2011 (11:54 am)
I have a 2003 GMC sierra 5.3. 130k miles... I bought new and have been testing the waters on many things, first thing i did was a tonneau covers hard plastic wrap over, +2.5mpg, then i did the K&N pfikit +1mpg, then i upgraded my wheels and tires to a more highway +1mpg, i tried the mass flow sensor from gannelli? both the K&N version and the plain version.. neither worked 1200 lost... then i replaced all gear lube in trnasfer cases mobil1 synth (+1mpg), i also did the auto transmition fluid in synthetic $55/qt mobil1 +1 mpg. I also ripped the mechanical fan off the front and installed a flexlite kit (runs cooler more HP ... no milage..) also in the winter the truck heats up better...
MPG average to date 18.0 town...20.5 highway ( not drafting)
next steps are exhaust and diablo code change/re-maper DiabloSport Trinity Tuner, Monitor: Gas and Diesel (T1000) so far this is the only one i have seen real results from ...
#144 of 176 Re: 08 silverado lost gas mileage [aaroncorpus]
Jul 11, 2011 (9:59 pm)
I had the same thing going on with my 08 Silverado. Fuel miliage fell to below 15 MPG HWY.(and I have the 4.3 V6 without A/C) Truck had 55000 miles.
I had the fuel injector system cleaned out by the dealer. The truck runs better and the gas miliage is the best its ever been. Just a tad over 20 MPG HWY now.
I always changed the oil regularly, and the air filter, but skipped the fuel system maintenance.