Home Forums Gear Hunting Trucks and Four-Wheel Drives New Silverado Mileage

I am wondering what mileage you are getting with your 5.3L 4WD Silverado's? I am disappointed with mine. I hope it gets better as is breaks in.

The best I have got on the road is 18 and more like 17 most of the time. I pulled a small two wheel trailer with a mower this past week end and got 14.5.

This truck has the 3.42 gears and is a crew cab.

I traded in a 2005 with the same engine and 3.73 gears. This truck would get 19 on the road and I am sure would have not dropped off much pulling this trailer. The new one has all of GM's gadgets for getting better mileage. The window sticker indicated 21 on the road.

Just wondering what everyone else is getting and if yours got better when fully broke in. Mine has 2000 miles on the clock.

couldnt tell yah, any figures i would give yah wouldnt be a very good comparison......ive got a lead foot from hell.....can tell yah where mine governs out at....need to get that fixed

7-08 fan hate to say it but that sounds about right. I have a 2009 Gmc Sierra CC 4WD bought it new. 5.3 liter, 3.42 gearing. 28,000 miles now. According to the on board display for the mpg's my truck gets 15 on the back country roads I frequent whether pulling a small trailer or not. And I really baby the gas pedal too. Haven't really been on a road trip in it so I really can't say about highway mpg. Good truck though! BTW, I'm a 7-08 fan too!

3.42 was a mistake. 3.73 gets better mpg.
Truck's too heavy, and 3.73 uses 4 cyl mode more.
I tested both ratios before I bought just using the DIC computer.
You aren't doing too bad though.

Same experience with my 2010 Silverado Z71. 3.08 gears and fuel 'puter. Struggles to hit 18.5 MPG highway.

My '06 Sierra Z71 w/3.42 gears and no fuel dingus, easily did 20 MPG highway. Both trucks ext. cabs, both with 5.3L engines.

Von, as far as I could ever tell, the 3.73 was not available unless I got the MAX which had the bigger engine. 6.2L.

Yes, I am thinking the 3.73 even with the six speed transmission would have been better.

Does yours have the 3.73 with the 5.3??

Don't go by the DIC. Only way to get true MPG figure is to hand calculate.

Z-

I've been averaging about 18.5 but haven't done any serious highway driving. (2010 5.3 Extended)

All that starting/stopping, glassing turkeys and deer is likely putting a hit on your fuel economy.

During the break-in period your truck won't get optimum fuel mileage. I wouldn't panic just yet with only 2000 miles on it. It's hard to say exactly how many miles it will take to fully seat the rings but it's not unusual at all for a new rig to take 2, 3 or 4000 miles to fully break-in.

Yes, I need to do a hand calculation of the mileage. On my 2005, the DIC was usually spot on so I have came to rely on it.

Not in a panic over the mileage, but just somewhat disappointed so far.. All the things GM did which was suppose to improve the mileage and it don't "appear" it will be what my 2005 with 3.73 gears was. To improve, GM went back to the lighter aluminum engine block, offered only 3.08 and 3.42 gears, went to a six speed transmission, and mandatory 4 cylinder to 8 cylinder computer aided engine cut out..then put 21 MPG highway on the sticker..

OH, on the 2011, GM makes it mandatory to use Dexos approved engine oil as well for the warranty to be good.. They charge the oil companies a premium to be certified and basically requires the owner to have a dealership change the oil so a record is officially made..Dexos approved oil is either a synthetic blend of fully synthetic..Not a lot of available oils on the list yet..I changed the oil at 1,500 miles and went with the AC/Delco blend..will probably go with Mobil 1 full in the future.

Scott...this truck has not seen the gravel or dirt, lol...That is the two Toyotas and yes, all the game watching does cut down on the mileage of them also...

Oh yeah, forgot about the Toyota. I'll see how the hunt schedule breaks down this year - I may try to make it down for the ML or rifle season. I'll give you a buzz - we'll see if we can't get your new truck stuck someplace.

Mine is a 2008 and it does have 3.73, 5.3, and 4sp 4L80E.
I do keep my tires over 40 psi and have a fiberglass tonneau cover.
The 6sp was supposed to help mpg before it came out, but I really haven't seen that watching the forums.
I'm very happy with my truck.
I would love to have the Vortec Max with the big motor and 4.10 gears, but I couldn't afford it - the purchase, not the gas. I don't think that the 6.0 (the motor at the time) was that bad on gas because in the half ton, it had the 4cyl mode too. I just didn't have the $$ for a loaded truck.
Now if you have the 6 speed, everything is a toss up for my knowledge because the first gear is stiff, so any rear end ratio would be acceptable for take off, but the double overdrive may be too tall at some point, and someone about to make a purchase would have to test several gears to find out the best ratio - based on their expected cruising speed. The state speed limits vary widely around the country. Also towing, if you do any, would be a balancing act vs unloaded.

Von

We have gotten 18.5-20 with our recent 5.3 GM trucks. Have noticed it to be speed dependent, go a few mph outside the "sweet spot" and mileage will drop off.

I bought a 2011 GMC 2500 HD crew cab with the 6 speed trans 3:73`s and the 6.0 and I have been averaging 16.5 to 17 on the highway. A word of warning about the 6.2 I was looking through my owners manual and happened to see that you are supposed to run 92 octane gas only or you will encounter heavy spark knock.

Kinser, that is pretty good/good to know. I also have a 2001 2500 Light Duty with the 6.0/3.73/4L80E and it got an honest 17 mpg at 70 mph before I put all my work stuff on it. I had not heard that great of figures on the HD's. Mostly 14 mpg because back in the day of the 4sp, if you got the 6.0 gas in the HD, you got the 4.10's which is why I chose the LD. Now I'd grab an HD gas OVER a duramax unless I towed extreme loads and especially at high elevation.

I have a 2004 2500HD,6.0 and I get about 13.0 mpg. I'm not into engines and trucks,but would like to know what I can do to get better MPG.Any help???

I am pretty happy with it ! My last truck was a 05 2500HD with the 4:10`s and 4 speed auto it usually only got 14 on the highway

The first thing that I would try is replacing the sparkplugs.

I just don't see it getting much better than that. Driving habits will help your mileage more than anything.

How come?