Poor Fuel Economy?

**Cummins20126.7** · 12-17-2017

Wondering if anyone has had the same issue. I bought my 2012 2500 6.7 in July of 2015 and it had around 83,000 miles on it. Since I've had it, my mpg's both hand calculated and lie-o-meter have been anywhere from 10-13. 13 almost never happens but only in the summer on interstate trips. I was wondering if either valve lash, grid heater or CCV filter could be causing this? My grid heater is caked in soot but not to where air cannot pass through (thanks to the egr), intake horn was cleaned out thoroughly 5,000 miles ago, truck is emissions deleted and taken care of meticulously such as oil changes, fuel filter changes, and air filter changes. I figured if it was the grid heater being clogged, I would see more soot out the tail pipe from the inability to meet the desired AFR. For valve lash, I know that it is set differently from the factory for a stock exhaust system but would changing it make a difference? I do have 35's on the truck but even on stock tires, I was seeing the same mpg's. And as for the CCV I don't have any check engine lights or service messages but I don't have any record of it being replaced, I might just delete it and see? Can anyone offer some help? Those were just my assumptions but if anyone has any other ideas let's hear em!

Update:
Just finished doing the CCV Delete and needless to say I wouldn't wish it upon my worst enemy. It wasn't hard to do but just took a lot of patience. Plus it makes a mess if you don't do it over the trash! Just a heads up

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**AnOldBiker** · 12-17-2017

I know you said it's a 2500, but do you know the rear end gear ratio ? (I've only known one 2500 having a 4:10 ratio)
Also, has the trans been serviced and the bands checked for adjustment ?

Also, check the manual, but I believe the valve lash isn't adjusted until 150k, unless the prior owner did it and messed up ...

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**Cummins20126.7** · 12-17-2017

Originally Posted by AnOldBiker

I know you said it's a 2500, but do you know the rear end gear ratio ? (I've only known one 2500 having a 4:10 ratio)
Also, has the trans been serviced and the bands checked for adjustment ?

Also, check the manual, but I believe the valve lash isn't adjusted until 150k, unless the prior owner did it and messed up ...

To my knowledge the gear ratio is 3.73. I checked the valve lash the other day and it was at stock adjustment. I know people adjust them when the put an aftermarket exhaust on, would I benefit from adjusting them?

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**theaaronbush** · 12-17-2017

The grid heater is certainly a restriction but I can’t say the fuel economy would suffer that bad if there’s still air flow but I’m not sure. I’ve deleted the CCV and grid heater on mine and run a GDP airhorn. I also have 35s on 20s with 3.73 gears and my EVIC averages around 17 combined. I also hand calculate every fill up as well and it’s about a mile per gallon off but I don’t do a lot of highway driving. Highway driving, EVIC instant fuel economy will read 20-22 mpg cruising at 70 all day long though. I average 10-12 mpg pulling my 10,000lbs travel trailer. Ram doesn’t recommend adjusting the valve lash until 150,000 miles I believe. Wheel bearings are good? You don’t possibly have a brake pad dragging do you?

2012 Ram 2500, 4x4, 3.73, 5” lift, 35" tires, Pure Performance TB, 5100s, 4" FloPro TBE, EGR valve/cooler/throttle delete, S&B CAI, GDP heater delete, GDP S2 air horn, Bestop Powerboards, RaceME Ultra Warp Tuning by DRD

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**Cummins20126.7** · 12-17-2017

Originally Posted by theaaronbush

The grid heater is certainly a restriction but I can’t say the fuel economy would suffer that bad if there’s still air flow but I’m not sure. I’ve deleted the CCV and grid heater on mine and run a GDP airhorn. I also have 35s on 20s with 3.73 gears and my EVIC averages around 17 combined. I also hand calculate every fill up as well and it’s about a mile per gallon off but I don’t do a lot of highway driving. Highway driving, EVIC instant fuel economy will read 20-22 mpg cruising at 70 all day long though. I average 10-12 mpg pulling my 10,000lbs travel trailer. Ram doesn’t recommend adjusting the valve lash until 150,000 miles I believe. Wheel bearings are good? You don’t possibly have a brake pad dragging do you?

2012 Ram 2500, 4x4, 3.73, 5” lift, 35" tires, Pure Performance TB, 5100s, 4" FloPro TBE, EGR valve/cooler/throttle delete, S&B CAI, GDP heater delete, GDP S2 air horn, Bestop Powerboards, RaceME Ultra Warp Tuning by DRD

Man I'd pay to get that kind of economy! I had my brakes changed and ball bearings changed in December of last year. I'm gonna delete the grid heater and CCV and go from there

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**TH-64** · 12-17-2017

Is your egr and throttle valve still in place?

Sent from my Samsung S-8 using Tapatalk... DRD tuned 2012 Ram 2500 CCSB, Saddle Brown Pearl

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**Whitewolf** · 12-17-2017

I'm wondering if you have a restriction in the exhaust. You said it was emissions deleted. Does that also mean the def and cat?

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**HKBIGDADDYDIESELDAN** · 12-17-2017

Originally Posted by theaaronbush

The grid heater is certainly a restriction but I can’t say the fuel economy would suffer that bad if there’s still air flow but I’m not sure. I’ve deleted the CCV and grid heater on mine and run a GDP airhorn. I also have 35s on 20s with 3.73 gears and my EVIC averages around 17 combined. I also hand calculate every fill up as well and it’s about a mile per gallon off but I don’t do a lot of highway driving. Highway driving, EVIC instant fuel economy will read 20-22 mpg cruising at 70 all day long though. I average 10-12 mpg pulling my 10,000lbs travel trailer. Ram doesn’t recommend adjusting the valve lash until 150,000 miles I believe. Wheel bearings are good? You don’t possibly have a brake pad dragging do you?

2012 Ram 2500, 4x4, 3.73, 5” lift, 35" tires, Pure Performance TB, 5100s, 4" FloPro TBE, EGR valve/cooler/throttle delete, S&B CAI, GDP heater delete, GDP S2 air horn, Bestop Powerboards, RaceME Ultra Warp Tuning by DRD

Hey bud how do you like your GDP airhorn ?

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