4.3 LV3 Fuel Efficiency

Grumpy Bear · September 22, 2018

The 5.3 and 6.2's have threads but I would appreciate some information on this topic from 4.3 owners. Thanks in advance.

Doublebase · September 22, 2018

What's your lifetime average, grumpy? I know it's pretty damn good.

cr250Silverado · September 22, 2018

According to averages reported by real world drivers on fuelly (.com):

the V6 averages 17.3 MPG (2014-2018)

the 5.3 V8 averages 16.5 (2014-2018)

the 6.2 V8 averages 16.2 (2014-2018)

Grumpy Bear · September 23, 2018

13 hours ago, Doublebase said:

What's your lifetime average, grumpy? I know it's pretty damn good.

Currently: 67,796 miles / 2506.44 gallons = 27.05 MPG (Gray Bar)

There are 9,3** miles not recorded. The 1,300 that was on her when I bought her and the remaining 8K ish between then and the start of this record. Those miles were lost to a hard drive crash and burn during a storm. There are roughly 77,500 miles on the truck presently with a tank unrecorded. And no, I don't practice typical hypermiling methods.

Thank you cr250Silverado for looking that up and posting those findings. (Red Bar)

10 hours ago, cr250Silverado said:

According to averages reported by real world drivers on fuelly (.com):

the V6 averages 17.3 MPG (2014-2018)

the 5.3 V8 averages 16.5 (2014-2018)

the 6.2 V8 averages 16.2 (2014-2018)

cr250Silverado · September 23, 2018

No problem, and wow your numbers are great! Are your figures per the display or hand calculated?

Doublebase · September 23, 2018

Looking at your chart it's obvious that you've "learned" how to drive it for best fuel economy over time.

2018 is ridiculously impressive. Obviously winter weather will drop it a couple mpg's but you'll still probably average 26.5 over the course of the winter months.

Now that I think about it, I've had fuel economy discussions with you on the 5.2/6.2 fuel economy thread. You do a great job.

Grumpy Bear · September 23, 2018

9 hours ago, cr250Silverado said:

No problem, and wow your numbers are great! Are your figures per the display or hand calculated?

These are all hand calculated with a corrected odometer and fuel tickets. My display numbers are hideously over valued. 8%+

2 hours ago, Doublebase said:

Looking at your chart it's obvious that you've "learned" how to drive it for best fuel economy over time.

2018 is ridiculously impressive. Obviously winter weather will drop it a couple mpg's but you'll still probably average 26.5 over the course of the winter months.

Now that I think about it, I've had fuel economy discussions with you on the 5.2/6.2 fuel economy thread. You do a great job.

It's a combination of things Doublebase and of course driving is part of it. Still over time my speeds have increased. What use to be difficult has become more turn key. This coming winter will be interesting indeed. I don't drive much in the winter, the truck that is.

During September this year 30 mpg at 60 mph is pretty common place if weather isn't to bad. Haven't been out much the last week. Harvest on in full swing. Roads are a mess and the wind picks up as the corn goes down. LOL.

I know there are at least two others that post here that have the 4.3 that do real well and I'm waiting for them to weigh it so we can share some information. Fact is I'd hoped anyone with a six would share. We learn from every experience, right?

KARNUT · September 23, 2018

My 14, 5.3, 342 gear GMC could easily get 24 MPG without the V4 at 65MPH. I documented in the gas mileage thread in the summer of 2014. My wife’s Genesis can easily get 30 MPG with a V-6 at 70 MPG. His mileage with a 2 door V6 truck especially driving for mileage I wouldn’t fine hard to believe.

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Grumpy Bear · September 24, 2018

22 hours ago, KARNUT said:

My 14, 5.3, 342 gear GMC could easily get 24 MPG without the V4 at 65MPH. I documented in the gas mileage thread in the summer of 2014. My wife’s Genesis can easily get 30 MPG with a V-6 at 70 MPG. His mileage with a 2 door V6 truck especially driving for mileage I wouldn’t fine hard to believe.

My 09 Buick 3800 V6 gets 30 mpg @ 70 MPH as well. Big difference, besides weight, between a Buick/Genesis and a 1999 or newer Chevy truck. Frontal area and Cd, right? The RC, DD and CC all have the same frontal area (stock). Cd's might be a bit different. Weight difference however can be considerable. Weight is a big disadvantage in stop and go or in hilly terrain.

That aero thing is a killer. A windy day is much harder on the truck than it is on the car efficiency wise. So I had to look elsewhere for my gains as I can't control the weather. I can, in that regard, only control what weather I choose to drive in and how I drive in it when my hand is forced. Call it impulse control. I would love to see this motor in a Buick Lacrosse or Chevy Impala. Oh... OR in a Malibu and call it a Chevelle...there's and idea GM! With the six speed that could be a 14 second ride that gets 40 mpg!!!

V-6 guys!!!! Calling all V-6 guys!!!

BTW Steve, 24 mpg at 65 out of a K2** pickup I would think to be really good. About double it's mid 60's counterpart, right?

KARNUT · September 24, 2018

My 09 Buick 3800 V6 gets 30 mpg @ 70 MPH as well. Big difference, besides weight, between a Buick/Genesis and a 1999 or newer Chevy truck. Frontal area and Cd, right? The RC, DD and CC all have the same frontal area (stock). Cd's might be a bit different. Weight difference however can be considerable. Weight is a big disadvantage in stop and go or in hilly terrain.

That aero thing is a killer. A windy day is much harder on the truck than it is on the car efficiency wise. So I had to look elsewhere for my gains as I can't control the weather. I can, in that regard, only control what weather I choose to drive in and how I drive in it when my hand is forced. Call it impulse control. I would love to see this motor in a Buick Lacrosse or Chevy Impala. Oh... OR in a Malibu and call it a Chevelle...there's and idea GM! With the six speed that could be a 14 second ride that gets 40 mpg!!!

V-6 guys!!!! Calling all V-6 guys!!!

BTW Steve, 24 mpg at 65 out of a K2** pickup I would think to be really good. About double it's mid 60's counterpart, right?

I was very satisfied with my gas mileage in my 14 GMC.

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Grumpy Bear · September 25, 2018

Alignment notes from the spring of 2017:

Before alignment 1475 miles on 55.84 gallons of fuel 26.41 mpg

After alignment 1589 miles on 56.89 gallons of fuel 27.93 mpg

1.52 mpg increase for a 6% gain. That’s 28 miles more range per tank and gets me over my 500 mile wish list target.

Pulled the above from my build thread and it's something anyone can do that will help no matter what your starting point. Alignment. I had this first done at 20,000 miles and wished I'd done it sooner but I expected a new truck to have an alignment in spec. It wasn't. Caster was at max. Camber was in but cross camber was off. Toe was hideously out of spec causing some steer ahead and the rear axle was out of square. The last two items providing a bunch of thrust angle. The dog walk.

I made note that post alignment it was more willing to engage the AFM. Ride improved as did handling. What's to hate, right?

It's more than just driving slow and/or conservative. Here was my starting point. Got out of the factory like this!

Edited September 28, 2018 by Grumpy Bear

ChevyChiver · October 26, 2018

I'm not sure how accurate the mpg calculator is in my truck but it's usually bouncing around between 18.5 and 19 . I get 12 towing my camper , a little less if I throw my golf cart in the bed . But overall I'm impressed with my little V6 truck . I used to have an old beat up f150 I towed my camper and hauled stuff with . This one is way better. Plus the savings from this truck I could get a motorcycle next one will probably be V8 but I'm good for now

AtlasFBG2 · October 27, 2018

I use mostly e85 in my 16 4.3 rc sb 4x4

The station I fill up at is actually 71% ethanol year round. Checked sensor with scan tool.

My daily commute round trip is 38.5 miles of 55-60 mph and 6 miles of 25-35 mph.

According to display I average 17.2 with v4 mode disabled. With v4 enabled I average 17.3 This was tested slightly over a thousand miles in both modes.

I will start hand calculate the average to see if it is different.

When I have used regular 87 octane fuel 10% ethanol and reset the display my average was 22.x mpg with v4 disabled.

AtlasFBG2 · November 8, 2018

My last 2 tanks of e85 I hand calculated the mpg at 14.2 and 15.6 The display read 17.1 and 17.3

With the price spread of regular vs e85 being only $0.27 now I switched to regular 87 gas. Will update mpg with regular 87 in a couple weeks.

AtlasFBG2 · November 24, 2018

Last two tanks of 87 octane I got 19.3 and 19.6 hand calculated. Display read 21.3 and 21.4

Below is the last five tanks of fuel hand calculated. The first tank of e85 I didn't check ethanol % with scan tool and got at a different station. It may have been higher percentage witch would explain the lower mpg. All tanks are with v4 afm disabled.

E85

14.2 mpg

15.6 mpg 71% actual ethanol

E30 26% actual ethanol Mixed tank of E85 and regular 87 octane

17.4 mpg

E10 8% actual ethanol regular 87 octane

19.3 mpg

19.6 mpg

Edited November 24, 2018 by AtlasFBG2