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Posted

I’ve had my new 2021 Sierra 2500 Duramax for about a month now and love everything about it except for the mileage. I’m seeing around 16 mpg on the hwy running around 70-73 mph and about 12-13 around town. I had a 3/1 level kit installed along with 35/12.50/20 Nitro Ridge Grapplers mounted on 20x9 rims with a 0 offset. Is it the level/tire/wheel package that is killing my mileage?

Posted

Yes.

 

Compare the weights of a stock rim to that aftermarket rim and do the same with your tires. If they added weight to each corner that means it takes more to keep them moving and reduces fuel mileage.

 

You also raised the front end way up compared to stock so now it's not as aerodynamically friendly, creates more drag and uses more fuel.

  • Like 2
Posted

From what I have read online that mileage with your set up isn't all that bad.  Could be worse.

  • Like 1
Posted
4 hours ago, gunner25 said:

I’ve had my new 2021 Sierra 2500 Duramax for about a month now and love everything about it except for the mileage. I’m seeing around 16 mpg on the hwy running around 70-73 mph and about 12-13 around town. I had a 3/1 level kit installed along with 35/12.50/20 Nitro Ridge Grapplers mounted on 20x9 rims with a 0 offset. Is it the level/tire/wheel package that is killing my mileage?

It's the width of the tires mostly that dropped your mileage.  Our 2012 with six in lift and 35s gets 15 rather than 18 on the highway because of the lift and tires.  She's shod with Trail Grappler M/Ts.  Each tire/wheel assembly weighs 40 pounds more than stock.

Posted

Never seen a Monster Truck yet that gets any kind of good mileage. Lol. All in good fun.

Posted

Leveling the truck reduces fuel mileage along with bigger, wider, heavier wheels and tires. Tires have a surprising amount of aero drag. As Earl mentioned, have you adjusted for the gearing of the larger tire circumference?

  • Like 1
Posted

Despite what anyone on this thread says, those tires arent hurting your mileage bad if at all. I’ve got a 21 that got 13mpg on the road when stock. It’s lifted now and gets 13mpg whether I’m on my 35s or 37s. There’s literally no difference between stock tires and 37’s. These trucks just suck on fuel. My 2015 duramax would consistently get over 20 with 35s.


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  • 2 weeks later...
Posted

Ditto nards444 comments, and add that taller tires reduce the numeric axle ratio and lift increases driveshaft angle. Neither "helps" gas mileage. If the mod is for cosmetics its a gift that keeps giving! If you off road in situations that require the additional ground clearance,  its the price of admission.

Posted
I still think its funny hearing people talk about putting 35’s on these trucks as if that’s such a massive jump from the factory rubber.  

I know. Like the 1/2” height difference will make a measurable difference in axle ratios and drag on a truck with pushing 1000ft lbs of torque. Hope y’all can afford the admission and to pay the fiddler. Whatever that means


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  • Like 1
Posted
On 4/24/2021 at 1:50 AM, Hobbypro said:

I still think its funny hearing people talk about putting 35’s on these trucks as if that’s such a massive jump from the factory rubber.  

It is for me, that's 3.5" taller and usually much wider and twice the weight.

Posted
16 minutes ago, swathdiver said:

It is for me, that's 3.5" taller and usually much wider and twice the weight.

Learned something new today.  It just seems weird that they would have that much of a difference in tires available on the same vehicle.  

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