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?

What about cold air intake,chipping it, that kinda stuff

not familiar with the stats for that particular engine but the whole cold air intake depends greatly on individual setups.....changes can be everything from not at all to quite a bit on some things......but it depends, any more most intakes are set up near ideal from the factory and an aftermarket cold air intake is a complete waste of money....

in poorly designed ones ive seen legit boosts of almost 40hp and other improvements.....with the tests being done immediatly before and after the install.....with alot of newer vehicles the change was small enough to either not be measurable or noticed....

Thanks

There are tons of threads about the diesel vs gas choice, but if I can boil it down to a sentence or two: the diesel excells at power especially at high altitude where any non-turbo engine looses power in thinner air, and SOMETIMES it gets a lot better MPG under load, sometimes not (the pre-urea DPF only engines didn't do so good). But lots of guys bought them because they were macho and just needed to pull 5-6K pounds. Now diesels are very civilized (quiet) and don't ride as bad as they used to, but they are horribly expensive to buy and maintain, complicated, and many times have been a lot more trouble than a gas engine (lots of bugs even though the strength was there). And the gas engines are getting simpler looking even if everything is computerized (look under the hood of my Chevy and GMC - the block is sitting there naked like in the 60's). If you need a diesel, get a diesel in spite of all the emissions crap they are messing them up with. If you tow once in a while and it is parked a lot, get a gas and don't worry about the 5 mpg loss. The $8K earning interest in an investment/6 qt oil changes/no regular fuel filter changes/cheap repairs easily covers that cost. Truth be told, there are a lot of farmers that are starting to realize (that actually own a calculator) that things have changed - especially where high mileage isn't concerned (working on the farm vs hauling an RV across the country).

Thanks for the detailed reply. I currently tow a 6,000 pound trailer about 5,000 to 6,000 miles per year. I want a new 2500 or 3500 hd but am torn between gas or diesel. I know I don't need the diesel right now, but I don't want to upgrade my truck again if I upgrade my camper. I am still contemplating my options.

Speaking of turbos, I'm a Chevy man, but can't help noticing a new, innovative F-150 engine. It's a V-6, the 3.5L, which is turbo charged. I hear it's $700 extra, but gives 23 MPG on the hwy., with major low end torque, a power curve much like a diesel. It'll do at 2,500 rpm what equivalent V-8's are cranking at 4,000 rpm.

My question, how long to you think it will take for GM to match it? I need that engine in a Chevy P/U...

The ford gets 22mpg not 23 and that is only 1mpg better then a current Silverado 5.3 4wd currently configured. I really have mixed feelings about that eco boost motor. Twin Turbos whether oil cooled or water cooled as in the case of the Ford motor cannot add to longetivity. A little over 200 cubic inches highly stressed is not the answer. That said if Ford manages to sell a lot of those ecoboost motors then maybe GM will follow suit.

With the 5.3 4x4 Chevy, what's the best axle ratios for 21 MPG?

I would get the 3.42....a guy I work with has that setup on a 2010 and gets 21-22 . My truck has a 3.73 and I get 20-21 on the highway... DF I know they offer a 3.08 but I know no one that has that gearset in their truck and if you go to the mother of all wisdom(internet) the reviews are mixed on its actual advantage.

How come?? Because that's what he has.

All this stuff about when and where and why to have a diesel is missing the point. You don't have to tow a lot to justify one of these. My everyday driver is diesel and very seldom used for towing......that's not why I got it. The only reason necessary for buying diesel is that it's just more enjoyable driving something with gobs of torque. The 5.3 is a really good engine but I wouldn't get another gas truck.

You might could order something higher but I believe 3.73 is standard.

Most of the 5.3's I have been seeing have either a 3.42 or 3.08 , the 3.08 is definitely as popular. I am also talking about trucks sitting in dealers lots, I have no idea what people are ordering.

I don't care what the dealers have setting on their lots. I refuse to buy any small-block Chevy that isn't a 3.73. A 4.10 would also be acceptable, if I could ever find one, when I am looking to buy. Cripes, 3.73's have always been the best rear axle ratio for a small-block 1/2 ton 4x4, way back when we ran smaller tires and didn't have overdrive. Now all these pickups have bigger tires, plus overdrive, and they want to run 3.08's? I also remember the 80's smog mobile dogs which had 3.08's with small tires and no overdrive, and were doggier than chit! Anybody else remember those?

I believe the late model 1/2 tons with the 403 horse 6.2 comes with the 6-speed transmission comes with 3.42's. Supposedly the 3.42's with the 6-speed auto lower first gear ratio actually has more dig than the older models with the 4-speed autos. Can't say, I don't have one.

If you plan on doing any towing, especially in hilly or mountainous regions, go 3.73's or 4.10, if you can find such a critter. If you drive nice flat level terrain, and the last 1/2 mpg is a really big deal to you, maybe 3.42's. As always, just my humble opinion.

As a FWIW, I once drove my (now) old '02 5.3 Z71 3.73 265's from Vernal to Casper. I filled up just before I left Vernal, drove through Flaming Gorge, Rock Springs, Rawlins and on to Casper. Filled up as soon as I got into Casper. Figured my mileage, and that truck got 21 mpg! I was astounded! Whatever.

The four wheel drive extended cab 2003 GMC Serria 1500 had the 5.3 and had the 3.73 gears. Best I ever could do on the highway with it was 19.8 MPG hand calculated. I traded it in on my current truck (2006 CC 2500 HD, 4X4 Duramax) I have got 22.8 MPG with the Duramax. It weighs about 7500 pounds and the 1500 weighed probably between 5000 and 6000 pounds. Duramax will tow about anything with ease. I pull campers and farm tractors from time to time. If I did not pull those items I would go back to a gasser. I bought the Duramax for the long haul and in the future might purchase a good used gasser to run around in.

My 2011 has the 5.3, 6 speed and 3.42 gears. As far as I could tell the 3.08 and 3.42 were all that was available. I wanted the 3.73. It only comes on the Trailer MAX with the 6.2L engine. It also takes high octane gas.

My 2005 had 3.73 with the 4 speed. Seemed more like a truck and got better mileage..

First gear in the 4 speed was 3.06 coupled with the 3.73 gave a final gear ratio of 11.41. Fourth gear was .70 and gave a final gear ratio of 2.61.

First gear in the 6 speed is 4.02 coupled with the 3.42 gives a 13.74 final gear ratio. Fifth is .85 which yields 2.90 and sixth is .60 which yields 2.05. This is providing my data and math are correct.

The 2011 feels like it has as much take off power or more than the 2005, which it should. I haven't pulled a heavy trailer so I don't know how it will handle one in sixth on the road.

The transmission does noticeably search for gears when you hit the hills.

My mileage may be getting a little better, but is seems the least little thing, such as wind, a little weight, or a dog pizzing on the tires really pulls it down. I still think it would benefit from a 3.73 ratio..I know Chevrolet advertises on this forum, I wish a Tech would chime in.....

No "mixed reviews" here. Traded a perfectly good '06 Sierra Z71 w/3.42 gears, on a 2010 Siverado Z71 w/3.08s and it sucks by comparison.

Less "stomp", less fuel economy. That GMC was a friggin' rocket from a dead stop.

Make sure you inflate your tires fairly high - like at least 50 psi or more if they are rated for it. The E load range tires will go up to 80 psi, but lots of people still do 32 psi like in their cars. Now it won't ride as good if you have rough roads, but it will help mpg. Watch the tread wear pattern. If you go too high for the weight, it will wear in the middle. Also, make sure they are balanced and you have a good alignment. And drive slower, of course.

Von

The 5.3 in our Yukon XL with 4.10 gears is a consistent 18 mpg on the highway, if the speed is right around 65 mph or so. About 12-13 in town and most mixed tanks will yield about 15

You will have a long wait if you plan on ordering a 1500 with a 3.73.

I can not fathom anyone haveing a truck with 308 gears in the rear end. I guess they don't wish to haul a payload or even pull any weight over 1500-lbs. Those 342 are better but more suited to a half-ton pickup that doesn't haul much.

I will not purchase or drive a pickup truck that does not have 373 gears in the rearend! Now most of the guys I know that run gas rigs towing use 410 gears. My cousins diesel 4 x 4 uses those 373 and has plenty of pulling power. I run a V-10 gas rig 1-ton and I have 373 gears and pull 10,000 like it is not behind me on level ground.

Me either, after having bought one about a year ago. Mileage sucks, in comparison to my old '06 Sierra 5.3L and so does performance from a dead stop. The GMC was a rocket w/342 gears, this one is a dog off the line.

Hadn't figured on pulling the double axle trailer as much as I once did with the GMC, so took the one Z71 ext. cab on the lot that I liked, 308 gears and all.

The 2010 has not gotten anywhere close to the 20 MPG highway, that the 2006 averaged. Still doing about 18.5 @ 12,000 miles.

My 2011, Z-71 has extended cab, not 4 dr. Otherwise, same set up as yours and at 600 miles, it's indicating an average of 15.8 mpg with city driving. It did say 21 mpg, hwy, on the door, but I'm not going to hold my breath on that one. I guess time will tell. It's a nice truck and I like it better than my brother's F-150. I've always liked the way a chevy pickup drives down the road. New F-150's do drive better than the older "walking I beams" they had for years.

DF

Went on a road trip on Monday approximately 520 miles. I ot 20.1 with my 5.3, 3.73 2004 silverado...that is 87 octane no ethanol...When I started putting in the ethanol halfway thru it dropped down to 18.8. I was going 70-75 using cruise control. The temperatures ran from 93 at home to 104 on the road.

Don't trade it on a new one...I did and am not happy...Wish the folks who advertise on the classified section would chime in here...That would be Chevrolet...

They rate rigs on mph differently for E85 ffv'S. On E85 they get significantly less. Too new to tell, but I have seen 21.5 on the DIC of my 2011 duramax. This was 55 mph highway with no regen cycles. I am sure overall it will be lower, but it will be no worse than my 2005 5.3l gasser. Amazing power for the mileage.

2011 Z71 is up to 16.5 mpg from 15.3 mpg with 2,000 miles on odometer. (5.3L, 4WD, 3.42, Ext. Cab)

DF

D-Farmer..I think mine has picked up a little possibly..I have 4000 miles on it..Just wondering your overall thoughts on your truck so far..They are nice trucks, but I still think they would benefit from 3.73 gears, at least on the top end..Also, mine seems to do quite a lot of gear searching..Does anyone know how well these transmissions are holding up if the truck is used as a truck..

I almost pulled the trigger on a new Z-71 last month and held off. I think that was a wise decision and I don't make many of them.

I traded an ext. cab, 4x4 2000 S-10, ZR-2 package, 4.3L V-6 that was a serious offroad truck, wearing a serious Warn wench. I was driving mostly highway and hadn't used the wench in several years. Still, I hated to see that little truck go. This Z-71 is more of a road truck and wouldn't go places the S-10 would. It's bigger and more comfortable, a great road truck. Drove it to New Orleans and back (3 hrs one way) this past weekend and it was as comfortable as my Tahoe.

Bottom line. I'm getting used to it. Had thought about the new 3.5L turbo F-150 (22 MPG road), but don't like the local Ford dealer. And I hate to get the first of anything, Ford built, notwithstanding. This 5.3L engine is a very proven design and should be about bullet proof. The Chevy dealer is a mile from my office and I've dealt with them for many years.

I signed up for an amazing deal. I do maintenance with them at a modest premium over Jiffy Lube prices and I don't have to wait. Drop the truck off, my office people pick me up and drop me off. Dealer checks and rotate tires and when they're down to a specified tread, they'll replace the set, FREE. That's right, 17" Good Year Wrangler A/T's. And twice during the life of the vehicle. I asked how they could do that and was told most people don't keep a vehicle that long. What! My S-10 was 11 yrs old and the truck it replaced was 12 yrs old. I think they'll replace those tires twice over the next 150,000 miles or so, which will take me around 10 yrs. of driving.

DF

My uncle get 14 tops with his 2007. He was suppose to get 20.

I think the quality of today�s fuel might play a part in the poor mileage. I drive a 2011 Chev. Tahoe as a company vehicle. It is a 2 wheel drive, 5.3 vortec with the 3.08 rear gear. The sticker said 15 MPG City and 21 MPG Highway. So far with 2050 miles on it the best I have seen is about 15 MPG and the worst was about 11 MPG. I hope it does better after it gets broke in.

10% ethanol gas is the norm today and has been in most areas where I travel.

As noted, my '06 GMC Z71 was rated at 15/19, regularly got 20 MPG on trips, if kept at about 72 MPH or a tad less. Occasionally got to 20.5. It was still doing that at 50,000 miles when I traded it last June. That truck had the aluminum 5.3L, four speed auto and 3:42 gears (or whatever the hell they were?). Same crappy 10% ethanol gas is used, usually Sunoco.

The 2010 Chevy Z71 has the same engine, 6 speed auto and 3:08 gears, plus fuel management 'puter. EPA rating is 16/21. Best I've gotten thus far on the same trip the GMC generally did 20 on over a four year period, is 18.5 MPG. Now have 13,000 miles on it, no change.

Only other difference, is the tires. The GMC had Bridgestone "highway" tires (HT Duelers), the Chevy has Bridgestone AT Duelers with a more agressive tread pattern, but I'm now running them at 37 PSI, instead of 35 PSI. Both trucks had/have the same type Access "roll up" tonneau cover on the bed.

Took mine to the local dealer today to get the rear differential fluid changed. Service writer told me the freaking throttle body was really carboned up. He top cleaned it and threw cleaner in the tank. I wonder how much my gas mileage will be on a road trip...72 mph or less is what my truck was doing when it got 20.1 on the last trip. I do not have a tonneau cover on it .

Most Chevy trucks (maybe all brands) will have a speed at which the mileage will really drop off. Most of our Chevy/GMC have done the best mileage between 65-70 mph

You guys are all making me feel happier by the minute that I own an '09 Dodge Ram Hemi..

My most recent trip to Phoenix from S. Colorado averaged, round trip, 19.6 mpg.- and this includes driving over a mountain pass and thru hills in New Mexico and Arizona, all at posted highway speeds.
Measured at fillup, BTW, not the digital MPG readout.

RAM......

HOw else would one measure mileage then at the pump ? There is at least 1/2 gallon discrepancy between what the dash says and the pump says when I fillup. I have not heard anyone rave about a Dodge Hemi's mileage...most people I know that have them in 2 and 4wd config have 16 as the best MPG they have.

A bud bought a new Ram crew cab 4x4 a bit after I bought my Chevy Z71 last summer. Last I'd checked, he was barely doing 16 MPG on the highway. His '06 F150 ext. cab 4x4 did about 17 or so. We both have hunting land in north central PA, about 30 miles apart, so it's roughly an identical trip for each of us.

Don't pay much attention to Ram or Ford gas engines, figure both of his were roughly the equivalent to my 5.3L GM engines?

I have a couple of friends with Dodges and my mileage with GM products has always been better, but granted, a pretty small sample size!