Extremely Poor Gas Mileage Troubleshooting

[rtr2000]

Thank yall so much for the suggestions. I just looked it up as well and my tires are 12 ply which is absurd considering I only off-road at the beach 3-4 times a year. Guess I could sell these and get some of the ones Cam suggested.

[rtr2000]

13 hours ago, richard wysong said:

on your op problem it may be the oring on the pickup tube to the oil pump DIYR has done extensive posts on the fix

Im new to this forum, what is DIYR? Is that like a username on here or a website with tutorials?

[dna9656]

17 hours ago, CamGTP said:

Remove your heavy tires and watch the mileage climb back up.

 

12-12.5 wide tires will eat away at fuel mileage. And if they are mud terrains with huge lugs for tread, forget about fuel mileage.

 

I bet you are at least 40lbs heavier per corner than a stock wheel/tire combo. Those 33's probably weight 60-70lbs each and the aftermarket rims can be heavy as well. Stock 20's in a non load range E are only 40-43lbs for most tires.

Agreed. Your tires are pretty heavy. Ideally you want to keep the unsprung weight (tiers and wheels) to a minimum; keeping in mind how you use your truck. If you off road A LOT you might keep those tires but since you don't you may want to rethink that.

[redvett]

On 7/15/2022 at 3:13 PM, rtr2000 said:

Also, do you think that a cold air intake might help it?

GM started putting cold air intakes on with the 1988 GMT400 so dont waste your money.

[richard wysong]

yes , user name DIYER I think

[shakenfake]

NNBS trucks are heavy bastards as well. You have a 5.3 with a 6L80 behind it which sucks quite a bit from you. Pair that with 4wd and you are meeting the gasoline maker.

[CamGTP]

Hopefully the OP gets back to this once he swaps tires, I'd like to know the increase in fuel mileage.

[ssrobzoom]

What are the diff ratios? 

[swathdiver]

The Nitto Trail Grappler M/Ts on our Sierra are 81 pounds each, not including the wheels.  They are 35s and the truck gets about 11 smiles per gallon as my daughter says!