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2019 6.4 Laramie Longhorn

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Indigo_54

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Hello all, I just got my first HD truck 2 weeks ago, I was coming from a half ton GMC Sierra

2019 Ram 2500 Laramie Longhorn Megacab Hemi with 28k miles on it, I tried doing a search on here for my two questions but did not find anything, hope I'm not the only one

I've read everywhere that the usual MPG city is around 11-12 but the best I've got is 9 mpg, not sure if that'll change with time or if there's something else wrong

Second, I got the Gas cap light warning last Wednesday, I googled the issue to see if I could find a quick fix, some people said the gasket on the cap wears out so I got a new OEM cap, light's still there and now the CEL came on this morning, I'm getting it looked at under the dealer warranty tomorrow

Are these common problems? I read that the older gens have gas cap issues but not the 19's and up, could the gas cap issue have anything to do with the poor MPG? I know it's a big gas truck and I'm not expecting big MPG numbers

Any input would be greatly appreciated
 
Are you hand calculating your mileage? Or using what the lie-o-meter says on the dash?
 
Mine is a 2020, but CC not MC. I get anywhere from 9-13 around town, depending on my right foot, traffic and how often I'm stopping for red lights. I have 3.73 rear gears in mine. I could see it being a tad worse if it had 3.92's in it.

For the gas cap / evap leak there are several reasons why that could be coming up. If you replaced the cap you need to complete 3 full drive cycles for the code to clear on it's own. You can't clear that code without a dealer scan tool. Another reason for that to pop up is a cracked vent valve on top of the gas tank. It's not a "serviceable" item, as far as the dealer/manufacturer is concerned, as it's molded in to the tank. There's a nipple coming off the valve that likes to crack. I've repaired them by breaking the nipple completely off, drilling out the tank and nipple side and inserting a piece of brass tubing inside. Then JB Welding the nipple back on.
 
Riccochet said:
Mine is a 2020, but CC not MC. I get anywhere from 9-13 around town, depending on my right foot, traffic and how often I'm stopping for red lights. I have 3.73 rear gears in mine. I could see it being a tad worse if it had 3.92's in it.

For the gas cap / evap leak there are several reasons why that could be coming up. If you replaced the cap you need to complete 3 full drive cycles for the code to clear on it's own. You can't clear that code without a dealer scan tool. Another reason for that to pop up is a cracked vent valve on top of the gas tank. It's not a "serviceable" item, as far as the dealer/manufacturer is concerned, as it's molded in to the tank. There's a nipple coming off the valve that likes to crack. I've repaired them by breaking the nipple completely off, drilling out the tank and nipple side and inserting a piece of brass tubing inside. Then JB Welding the nipple back on.
Click to expand...
Did you have to lower the tank or lift the bed to do the vent tube/nipple fix?
 
Indigo_54 said:
First post

Hello all, I just got my first HD truck 2 weeks ago, I was coming from a half ton GMC Sierra

2019 Ram 2500 Laramie Longhorn Megacab Hemi with 28k miles on it, I tried doing a search on here for my two questions but did not find anything, hope I'm not the only one

I've read everywhere that the usual MPG city is around 11-12 but the best I've got is 9 mpg, not sure if that'll change with time or if there's something else wrong

Second, I got the Gas cap light warning last Wednesday, I googled the issue to see if I could find a quick fix, some people said the gasket on the cap wears out so I got a new OEM cap, light's still there and now the CEL came on this morning, I'm getting it looked at under the dealer warranty tomorrow

Are these common problems? I read that the older gens have gas cap issues but not the 19's and up, could the gas cap issue have anything to do with the poor MPG? I know it's a big gas truck and I'm not expecting big MPG numbers

Any input would be greatly appreciated
Click to expand...
I have a 2019 bighorn CCLB gasser with about 100k miles on it I think and I get about 11-12 mpg city still. Don't do much city driving, but it stays around there when I do. I'm a habitual smooth driver though.
 
Thanks for the input so far, crossing my fingers the dealer can fix the gas cap issue, the truck drives great, this morning I got up to high 9's mpg on the screen lol

I've only driven it about 80 miles since getting it

Like I said not expecting big MPG numbers, I work about 8 miles from home so I was just curious, this Hemi has so much more power and response than the 1500 GMC had, it's night and day and I used to only get about 12-13 mpg on that so its totally worth it
 
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I wish I could get a steady 10MPG city but like others said, it all depends on right foot and stop light waits.
I get about 12.5 on the highway, but I'm usually doing 80 MPH
 
Got the truck back from the dealer today, it was a evap leak, got it fixed and it's running great

Gonna hand calculate the miles on this fresh tank, see what I get
 
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