I am in the market for a new truck. Pretty much narrowed it down to the 1500 GMC or Chevy. Trying to decide between the 5.3l & the 6.2 l v8 engine. I will tow with it but it isn't going to be the main function.

What kind of mileage are you getting? Are you able to run 87 octane or are you having to run premium?

I have tried to look for articles on it and not had any luck finding any, so looking for some first hand experience.  

Thanks

The 6.2's run like crap unless you run the recommended premium fuel. They do get decent mileage but not as good as the 5.3 which only requires regular gas.

Very happy with the 5.3L so far in my 2016 Silverado.
I usually run regular gas but when I drive to the gas station that has no ethanol fuel to get gas for my small engine stuff I fill up with the premium. I see a difference in milage but the fuel costs more.
As for milage I average about 16 mpg.
I got the GM Performance Exhaust which I really like as well.

Attached File

The website Fuelly.com shows the avg. for 2016 5.3 @ 16.6mpg.  For the 6.2 it's 18.4mpg but only three 2016 trucks participating.  If you avg. all the years for the 6.2 it's 16.6mpg.

My past 3 trucks have had the 5.3 and they are great motors. I would however like to have the 6.2. My current 2016 Silverado has a 5.3, 295/70-18 Cooper STT's and I'm getting 16-17 mpg on 87 octane. Attached File

I've got a 14 Chevy with the 5.3 and I average 19 to 20 on regular gas. BUT the vast, vast majority of my driving in it is steady 65 -70 mph.

When I'm just running around town in it I get more like 17.

ETA: I baby it most of the time too.

I have a 2013 GMC Sierra Denali with the 6.2L engine. I don't think I will ever go back to the 5.3L. I have found that I get the same gas mileage with the 6.2 as I did with the 5.3 and my Denali is AWD all the time. No option between 2 or 4 wheel.

You have to run premium in the 6.2 so it might be a little bit more, but it is totally worth it. You can run 87 in it, but it can cause a knocking noise from the engine (I have never tried it because I plan to drive this truck for a while).

I tend to take it pretty easy when I drive. I drive 70 on the highway and get 19 MPG. With city driving I probably average 14.5 MPG.

2016 Z71 LTZ Plus with the 6.2l





That's straight highway mpg with summer blend fuel. Now I am getting about 22-22.5 and combined around town and hwy I am at 19. According to my remote link for the life of the truck it has averaged just over 21 mpg.

The answer you seek is the 6.2. I have a 2015 with the 5.3, wanted the 6.2 but didn't absolutely need it for the extra money it costs. I like the engine, the transmission however, I am not a fan of. GM has too many nanny programs for fuel economy that makes the shifting feel clunky and underpowered. It bogs a lot at slow speeds while accelerating and I absolutely can't stand AFM. I hate the noise it makes when it goes to four cylinders and it lurches when it goes in and out of V4/V8. Garbage, I need one of those Range plug in AFM delete thingamajigs.

I have heard complaints on some of the things you mentioned but I have experienced none of them with my 16 6.2 and the 8 speed. The clunk a few times but it was just when I pulled my foot off the accelerator right as it shift. Any person that knows cars can figure out the patterns of your vehicle and make sure to drive it properly. Mine doesn't lug, doesn't lurch between 4 and 8 modes. I put a 18" magnaflow on mine and deleted the resonator. I also used a hose clamp to keep the exhaust valve wide open. It doesn't resonate at all and barely helicopters in 4cyl mode. You have to try to hear it to hear it. The sound though is awesome with the magnaflow. The 6.2 was the best decision I made. Traction control off from a 20 mph roll and stomp it, it will haze the tires.

I think he is talking about the 5.3L. I don't think the 6.2L has AFM.

This guy may or may not be a GM dealer...

I've never had these problems with my '14 5.3L. I've never been able to detect the switch from V4 to V8 or V8 to V4.

My only complaints about the truck are that if you turn on the AC seats, it exhausts warm air out of the back of the seat onto passengers in the rear. Also no AC vents in the rear. But those are problems for my passengers, not me


ETA: It's literally the best vehicle I've ever owned.

But that's going from a '89 Ford Escort, to a '97 Ford Mustang, to a '10 Toyota Corolla (still own this one), so my '14 Chevy Silverado LTZ feels like the most luxurious vehicle on the planet.

I've got the 5.3 in my swb Sierra. The truck is in reality overpowered, but if I had a crew cab or anticipated hauling shit regularly, I'd go with the 6.2.

I have the 5.3 and I have driven the 6.2 with 8 speed. They both seemed to have that nanny program in the trans. Basically, what mine does, if I accelerate normally, not aggressive, from about 20 mph it tries to stay in a higher gear, then it bogs down, I put in more pedal and nothing happens. Eventually it will shift down, but it takes forever and it hunts at least two gears before it settles on one and then the rpms ramp up and all is well. But this process happens all too often and is very noticeable. My 2004 that had 166k on it shifted better. This is a common occurrence on these trucks, just hunt around on GM forums, it's not just me.

The AFM causes the truck to lurch while it is cruising on pretty flat ground, definitely noticeable to me.

The electronics also aren't too whippy. On more than one occasion the steering wheels controls froze up, the radio cluster has malfunctioned and is slow to respond, and now one of my parking sensors is malfunctioning. it looks more and more like I got a lemon. I like the truck, it's nice, but it has been far from consistent performance. My 2004 was rock solid, never should have traded it in.

ETA: Forgot, my compressor also locked up and has been replaced at 18k miles.

5.3, average 17 city 20 highway. Have about 72k miles on a 2014.

I have a 14 Double Cab 4X4 with the 4.3 V6 and love it.   I can average a true (Not DIC) 19 mpg in mixed 50/50 driving during the summer on some tanks with minimal idling.  Highway cruising is all about the wind and cruise setting and varies accordingly, figure 16 or so at a hilly 10 degrees into the wind and maybe 23 going 70 on a perfectly level road at 65 or so.

I love the 6 spd.  Yes, it tries to keep you low, almost like a diesel and the motor is surprisingly amenable to pulling high gears at partial throttle.  In your case, I'd try to balance the cost of the 5.3 vs 6.2 and check payload on the door sticker.  Your payload rating will probably suffer by the weight of the bigger motor.  You can also run E85 in the 5.3 and get about 400 HP according to GM.  I've used E85 on occasion and it is a totally seamless transition- you just get less MPG.

Any of you guys listing your MPG's have a level kit?  Thinking of doing the Rough Country 2.5 front and 1" rear and changing nothing else and wondering if anyone has seen a mpg difference after this.

OP,,,A bit off the subject BUT. I`ve had so many new trucks in my life that I can`t remember them all. I always bought the truck that I needed for the work /chores I was doing. We ( retired a few years ago) recently replaced our Ram 3500/ 40 ft. fifth wheel with a new motorhome and a 2016 GMC Canyon. I just love this little truck!!!! The rationale was to find a pickup that we could flat tow behind the motorhome(all four wheels down). Our choice was this or a Jeep.

After driving this truck for a couple of months I have come to truly like it. It will do ALMOST what a GMC 1500 will and in some ways much more. Easy to park, wife likes the way it drives, plenty fast, pickup bed that I CAN ACTUALLY REACH OVER AND GET SOMETHING!

It is all leather, 4wd , heated and cooled seats. Great stereo. And more and more.

Thanks for the replies. I won't be making a purchase until some time in the next 2 weeks so any more feedback is more than appreciated.

So a couple of follow up questions . . . . to those that have the 6.2L are you having to the 93 octane fuel?  I know someone posted above that they had to use premium or they got a knocking sound.

A little more background about my intended purpose. I am moving from NC to the northwest. I will be a sales rep servicing WY, MT, ID, OR, and WA. I am going to have to drive a ton and carry an adequate amount of samples. I will have access to a bigger towing vehicle when I need to move horses but in the back of my mind I will eventually buy a 2 horse trailer that would be a lot easier to pull around regardless of truck. So pulling is not a major concern.  I normally would look at used vehicles first but with such a big territory and I only know 15-20 people in 5 states so that warranty carries a little extra protection that a used vehicle may not. My current driver is just at an age where driving it that many miles, my concern would be staying in the shop more than on the road.

To the post above me, yes I liked the Colorado/Canyon. I drove one of those Saturday as well. My only hesitation is that as much time as I am going to be spending in the vehicle, I kind of want to splurge on the 1500 a little for the extra room. I currently drive a  2003 2500HD crew cab diesel with 220,000 on it. I am just afraid of changing too much size, from a 3/4 crew cab to a Colorado would be a considerable amount of room difference. However, that extra mileage is attractive. And they are a nice looking little truck. I still can't figure out why they put running boards on that low of a truck.

AFM is terrible. I will sell you a range device this coming summer if you want one cheap. I am going full tune in my 6.2.

My 11 Denali pickup with the 6.2 would do the early up shift around town when driving easy, the simple cure was just pop it in tow mode...no noticeable difference on fuel economy either..mine also ran fine on 87 octane....

In my 16 6.2L I run mostly premium but do mix it up with a couple tanks of 87. No real difference in economy. If it his a hot day and have 87 in the tank I do make sure to drive it conservatively.

I have a 2015 GMC 1500 Z71, 4x4 extended cab reg bed, 3.42 gears.  I bought it new and it has 20k on it now. Back and forth to work, mixed driving I get 20 on summer gas and 19-18 on winter blend.   Best on a trip to Cape Charles and the outer banks, 27.  But I am running stock size tires, I've left the air dam on, no leveling and I do run 93 octane.  Additionally I swapped out the intake pipe for an Airraid pipe.  The stock one has all kinds of baffles for noise.  Also I put a Dynomax VT exhaust on.  This exhaust and the GM performance are the only two I know of that have the flapper to help with the drone of the V4 mode.  V4 on flowmasters sound like a helicopter and would drive anyone nuts.

When I get real gas it gets even better.  If you run E85 the power jumps a good bit, enough to feel it in the seat of the pants.  If you run 93 octane in the 5.3 its enough to feel as well.  One of the truck tuners put a 5.3 on a dyno and better numbers with 93 octane, and then even more(20 hp and 20 tq) with E85.  The delta between 87 and E85 is substantial by the seat of the pants.  But E85 mileage is worse, much worse.  

If you plug in your scanner, you can see it pull timing with all blends of gas, but 99% of the time I run 93, esp in the summer and when towing.  

The 6.2 requires 93, at least in 2015 when I bought mine that was what they advertising and the 6.2 was right at $2500 more, IIRC.

Here is a hack for all those who replied who own a 2014+    When you start up, hold the tow mode button in for 5+ seconds.  This switches the transmission program and turns off the grade braking.  The shifting smooths out, you get better mpg and unless you're towing, you really don't need the engine braking to save your brakes.    You have to do it every time you start your truck but I swear by it.  

Go over to  GM Truck forum  Lots to read

I almost bought a Canyon.  But I do tow a 7000 lb trailer, which is the high end of what it can do.  But the biggest thing for me was the cost.  I got my Sierra for less after discounts.  They just wouldn't come down on the Canyon.  And I am a little shocked the diesel only nets you like 500lbs more capacity.  I expected more considering the extra cost.  But it is  a great truck.  

BTW I can't call it a little truck.  You should see one parked next to say a 1990's 1500.  They are just about the same size!

Mixed highway and city I am getting about 16-17 MPG and I am a little bit of a lead foot on my 5.3 2016 Silverado

I think everyone in this thread really means 91 Octane.  This is the actual requirement from the 2015 owners manual.  In my experience, the vast majority of premium fuel is 91.  In my area, only the local Harley shop sells 93 octane gas based on find93.com's website.



If the vehicle has the 6.2L V8 engine
(VIN Code J), use premium
unleaded gasoline meeting ASTM
specification D4814 with a posted
octane rating of 91 or higher.
Regular unleaded gasoline rated at
87 octane or higher can be used,
but acceleration and fuel economy
will be reduced, and an audible
knocking noise may be heard. If this
occurs, use a gasoline rated at
91 octane or higher as soon as
possible. Otherwise, the engine
could be damaged. If heavy