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NHT and 1/2 ton towables

Donstar

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cire0309 Enthusiast

cire0309

Posted
Posted
One concern I have is if the 3.73 gearing throws the 5.3's mpg's out the window.  I'm thinking that the 5.3 has some pretty impressive numbers but these are based on the 3.08 gears.  I wonder if there are members that can comment on any potential hit on fuel economy.


Donstar, I had a Vortec 5.3 with 3.73 gears and the 4L60 in my Avalanche. Not exactly the same as the current setups but the sticker said 15 city and 21 highway. Didn’t see anywhere close to that. Lifetime average was 14 mpg of mixed driving. I was able to get almost 18.5 mpg on road trips (almost 100% highway at 75mph). This is why I’m not too concerned with 12 mpg average from the 2500.

The 3.73’s definitely hurts the mileage and I have a pretty heavy foot because of work habits. The Ecotec is both more efficient and powerful. It’ll do pretty well put probably won’t squeeze out the mileage your 4.3 gets.
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Imcrazy Senior Enthusiast

Imcrazy

Posted
Posted
34 minutes ago, Donstar said:

One concern I have is if the 3.73 gearing throws the 5.3's mpg's out the window.  I'm thinking that the 5.3 has some pretty impressive numbers but these are based on the 3.08 gears.  I wonder if there are members that can comment on any potential hit on fuel economy.

AH I assumed that you were going after a 6.2L... Keep in mind that not only the gearing but, the tire weight on the stiffer tires they put on the max tow trucks... I'm guessing they're using LT tires , not P metric?

 

I can tell you that I get about 18mpg between hwy and city with my 5.3 with 3.42's but, I can get 22-24 if I keep it around 60 or less on a flat hwy stretch of about 100 miles... Normal hwy driving around here has some hills and speed limits of 65-70, if I run those around 70-75 mph I get about 20 mpg if I am lucky...

Diver6 Enthusiast

Diver6

Posted
Posted

I just got home today from a 3700km trip through the smokie mountain's with my 16 NHT 6.2l and 29.5 Jayco eagle HT 5er with now problems at all.

I'm over weight by 700 lbs but truck handles great and stops great. Got 10MPG(23L/100) in the mountain's with cruise set at 100km. I talked to fellow campers with diesels and they only get 11 MPG and spent 12K more! I found premium fuel and diesel were the same price in the US. would love a 2500 but since its my everyday truck can't give up the fuel mileage with the 6L and can't justify the price of the diesel.

sldhead700 Enthusiast

sldhead700

Posted
Posted
AH I assumed that you were going after a 6.2L... Keep in mind that not only the gearing but, the tire weight on the stiffer tires they put on the max tow trucks... I'm guessing they're using LT tires , not P metric?
 
I can tell you that I get about 18mpg between hwy and city with my 5.3 with 3.42's but, I can get 22-24 if I keep it around 60 or less on a flat hwy stretch of about 100 miles... Normal hwy driving around here has some hills and speed limits of 65-70, if I run those around 70-75 mph I get about 20 mpg if I am lucky...
2017 6.2 8 speed nht numbers are about the same as yours. I couldn't Believe it either but I looked at my truck and the are "p" not lt

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sldhead700 Enthusiast

sldhead700

Posted
Posted
You are correct.  I could go with a Ford and have a V6 but the GM 5.3 is my second choice to the 4.3 V6.  (The 4.3 with  3.73 gears  would be an awesome and capable tow machine!)
Lol, I'm glad the factory doesn't agree with your assessment of a v6 as being awesome, and offers the "rest" of us a different choice.....
Hopefully the mpg listed by others gives you an idea as to what expect from the NHT.( Pretty accurate from what I see)
Not really sure what you are getting with your v6 currently, unloaded and loaded, as to how big of a hit that you will take in mpg.
I'm betting loaded, you will be better with either of the v8's and Nht package though.

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ray2005 Enthusiast

ray2005

Posted
Posted



AH I assumed that you were going after a 6.2L... Keep in mind that not only the gearing but, the tire weight on the stiffer tires they put on the max tow trucks... I'm guessing they're using LT tires , not P metric?
 
I can tell you that I get about 18mpg between hwy and city with my 5.3 with 3.42's but, I can get 22-24 if I keep it around 60 or less on a flat hwy stretch of about 100 miles... Normal hwy driving around here has some hills and speed limits of 65-70, if I run those around 70-75 mph I get about 20 mpg if I am lucky...


This mileage sounds exactly like mine. 5.3, 8 speed, 3.42 NHT.

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TXGREEK Senior Enthusiast

TXGREEK

Posted
Posted

2018 6.2 cc z71 cruising 75-70 gives me 22-23mpg


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Donstar Senior Enthusiast

Donstar

Posted
  • Author
Posted
3 hours ago, sldhead700 said:

Lol, I'm glad the factory doesn't agree with your assessment of a v6 as being awesome, and offers the "rest" of us a different choice.....
Hopefully the mpg listed by others gives you an idea as to what expect from the NHT.( Pretty accurate from what I see)
Not really sure what you are getting with your v6 currently, unloaded and loaded, as to how big of a hit that you will take in mpg.
I'm betting loaded, you will be better with either of the v8's and Nht package though.

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I'm sure it's more of a case of sales marketing that determine whether optional gearing will work with a V6.  Yesterday I was looking at pictures of my new Suburban taken in 1985 alongside my new travel trailer.  With less torque and half the horsepower of my current V6, the Suburban's V8 hauled my family, their gear and trailer effortlessly.  ;-)  I currently pull a 21 ft travel trailer with my V6 and it is not short on power.  My motivation to buy a NHT is for the increased payload.  The extra power is a bonus but not if it significantly increases my daily operating costs. 

ray2005 Enthusiast

ray2005

Posted
Posted

NHT is the rpo code for the max tow package. It has different springs, 9.76" rear, different shocks and enhanced transmission cooling.

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Imcrazy Senior Enthusiast

Imcrazy

Posted
Posted

I can't imagine the annual fuel cost going up tat much by switching to a Max Tow 5.3 how many miles a year do you drive?

Donstar Senior Enthusiast

Donstar

Posted
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Posted
3 hours ago, Imcrazy said:

I can't imagine the annual fuel cost going up tat much by switching to a Max Tow 5.3 how many miles a year do you drive?

You're probably correct. I am currently averaging about 12,000 miles per year on my truck.  I calculated the difference between averaging 19 and 20 mpg for every 1,000 miles.  I would pay a difference of $15.21.  This is not bad.  If you compare an average of 18 mpg to 23 mpg then the cost difference over 1,000 miles is $70.60.  These figures are based on an average cost of $1.50 per litre (I currently pay more) converted to US gallons.  (These figures are also just examples) My last truck was a vortec 5.3 with larger LT tires and the less trips to fill up with my current truck are noticeable.  Poor mileage is one aspect of the good ol' days I don't miss!

redwngr Senior Enthusiast

redwngr

Posted
Posted
18 hours ago, Donstar said:

One concern I have is if the 3.73 gearing throws the 5.3's mpg's out the window.  I'm thinking that the 5.3 has some pretty impressive numbers but these are based on the 3.08 gears.  I wonder if there are members that can comment on any potential hit on fuel economy.

My 5.3 NHT 8 speed got better mileage than the 6.2 8 spd (not NHT) it replaced.

Factoring in the difference between regular an premium it was significantly cheaper to run. 

 

Pulling enclosed V-nose utility trailer across the continent on interstate the 5.3 NHT only gave 8-9 mpg.

 

One of the biggest advantages of the 2500's when towing longer distances is the size of the fuel tank. 1500 std and short box are all 98L/26gal while the 2500/3500's are 136L/36gal.

Fuel station spacing when carrying 26 gal (20 -22 usable?) getting 8 or 9 mpg becomes a problem -- often fuelling early because if not it was only going to get 1/2 way to next station.

 

22 gal x 8.5 = 190 miles, 32 gal x 8.5 = 272 miles  (pulling the same trailer, the dmax would still be in double digits - easily giving over 300 mile range. )

 

Clearly fuel stop planning is greatly simplified with +/- 145% greater usable fuel volume.  (32 / 22 x 100% = 145%)

 

If towing distances is a primary motivation, do not underestimate the extra cost for premium fuel.  

 

 

As you can see I gave both the 5.3 and 6.2 a shot and went back to Dmax. 

 

ymmv

redwngr Senior Enthusiast

redwngr

Posted
Posted
3 hours ago, ray2005 said:

NHT is the rpo code for the max tow package. It has different springs, 9.76" rear, different shocks and enhanced transmission cooling.

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It also includes tow mirrors as well, and is the only way to get them factory installed. 

Includes trailer brake controller, which is available without taking the full NHT package.

 

The tow mirrors are expensive thru gm accessories/parts.

 

Depending on transmission/engine combo it also includes a different ratio differential(s)  

 

 

NHT         Max Trailering Package, includes 9.76" rear axle, 8-speed transmission with 3.42 or 6-speed transmission with 3.73, (JL1) trailer brake controller, enhanced cooling radiator, revised shock tuning for increased control, heavier duty rear springs and increased RGAWR

 

On SLE - Requires a Crew Cab or Double Cab model. Includes (G80) heavy-duty automatic locking rear differential on 2WD models (already standard on 4WD models) and Z82 Trailering Package. Requires (L83) 5.3L EcoTec3 V8 engine and (DPN) power camper mirrors. Not available with (SXL) Elevation Edition, (Z71) Off-Road Suspension Package. Includes (UHN) 18" X 8.5" bright-machined aluminum wheels. Requires (RKX) 18" tires or may upgrade to (RD3) 20" bright machined aluminum wheels with either (RC7) or (QSS) 20" tires. 

 

On SLT - Requires (RKX) 18" tires or may upgrade to (RD5) 20" chrome wheels with either (RC7) or (QSS) 20" tires. With (L86) 6.2L engine, requires (RD5) 20" wheels with (QSS) 20" tires. Requires (DQS) power adjustable, power folding camper mirrors. Not available with (GAT) All Terrain Package and (Z71) Off-Road Suspension Package.

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