Slumping fuel economy

[Scap]

Man, there has to be something with the fueling going on here. Highway economy has been steadily dropping for the last 1-2 years. Used to get 22, then 20, then 19 now this?? Daily driving economy had plopped from 16-17 down to 14-15 too. I drive like a grandpa and I notice the ECO light seems to come on less and the truck seems to downshift more on sight uphills. Can there be a dirty sensor? Something clogged? Something needs reset? Is this what happens as the ET battery ages? Just drove 12 hours round trip along the Gulf Coast, no traffic, 75 mph with adaptive cruise, same 87 Shell gas, just like every other drive I've had and the highway mpg just continues to trend down. Just turned 50k on the odometer. This is 100% highway miles and pretty representative of the entire 850 mile trip...

I'm sitting at right about the same mpg.

 

[DEG]

I'm sitting at right about the same mpg.

Same as what? Same as his previous readings or current readings?

When I first read this thread I thought maybe the dealer had flashed his computer during a visit and the flash corrected inflated inaccurate MPG readings. None of my Rams have ever seen 22 MPG except when coasting down a mountain.

I just finished a 3000+ mile all highway road trip from St Louis to Tucson and back and averaged 17.3 according to the truck computer. When I manually calculated the MPG it's always within a half of MPG of what the computer says, but the manual calculation has never been better than what the computer says. I had a few tanks that nearly reached 19 mpg and a few with a headwind that didn't reach 16 mpg. I'm sure I could have reached 20 MPG with the cruse set on 60 or 65 but then I would have been risking my live as the interstate speed limits were mostly 75 or 80 mph. My readings are typical of every Ram I have owned.

 

[BowDown]

Man, there has to be something with the fueling going on here. Highway economy has been steadily dropping for the last 1-2 years. Used to get 22, then 20, then 19 now this?? Daily driving economy had plopped from 16-17 down to 14-15 too. I drive like a grandpa and I notice the ECO light seems to come on less and the truck seems to downshift more on sight uphills. Can there be a dirty sensor? Something clogged? Something needs reset? Is this what happens as the ET battery ages? Just drove 12 hours round trip along the Gulf Coast, no traffic, 75 mph with adaptive cruise, same 87 Shell gas, just like every other drive I've had and the highway mpg just continues to trend down. Just turned 50k on the odometer. This is 100% highway miles and pretty representative of the entire 850 mile trip...

Thats a 65 mph, I've never gotten 21-22 mpg driving that slow. You have the same gear that I do and at 65, im at 18-19 mpg, speed up to 70 or 72 and Im at 22-23 mpg, speed up to 74 and Im at around 21 mpg. Im at 70K miles now and my MPG has been dead consistent since the 1st tank fuel; 17/18 80/20 mixed city/highway driving and 21-22 mpg on the highway @ 72-74 mph. What I would wonder about are the weather conditions you're observing this mileage in; cold or hot, strong headwinds?

A 7-10 mph headwind kills my mpg, 21-22 down to 18. Seen it many times driving dallas to houston, esp in the winter

 

[smashweights]

Thats a 65 mph, I've never gotten 21-22 mpg driving that slow. You have the same gear that I do and at 65, im at 18-19 mpg, speed up to 70 or 72 and Im at 22-23 mpg, speed up to 74 and Im at around 21 mpg. Im at 70K miles now and my MPG has been dead consistent since the 1st tank fuel; 17/18 80/20 mixed city/highway driving and 21-22 mpg on the highway @ 72-74 mph. What I would wonder about are the weather conditions you're observing this mileage in; cold or hot, strong headwinds?

A 7-10 mph headwind kills my mpg, 21-22 down to 18. Seen it many times driving dallas to houston, esp in the winter

Good question. My road trips are always Thanksgiving, Christmas, New Years. No idea on winds but my best mpg was 23 hand calc driving Ohio to Florida at 70mph for Thanksgiving 2 years ago.

 

[RAM Patriot]

When my MPG starts to drop. ( I monitor it every time I fill up with an app ), I pour a bottle of Sea Foam in the tank prior to fill-up.

This stuff will clean deposits on the fuel injectors, and cleans up deposits on your intake and valves.

The mileage returns to normal usually on the 2nd to 3rd tank of fuel after running this through the system.

How to use Sea Foam in fuel

No Description.

seafoamworks.com

 

[Shumax2]

Traded in a '19 RAM 1500 for a '23. Same engine. I do (4) 500 mile trips a year to second home and always got 22-23 mpg driving 70-75 on interstate with cruise with the 2019. Just finished my 2nd trip with the 2023 and got 17.5 mpg each time. The trips are every 3 months so its not just seasonal blend ... I am traveling in all seasons. I have noticed that the ECO light doesn't come on very frequently with the new truck. I've asked the dealer to take a look at it but based on his reaction I'm not expecting much.

 

[Scap]

Same as what? Same as his previous readings or current readings?

When I first read this thread I thought maybe the dealer had flashed his computer during a visit and the flash corrected inflated inaccurate MPG readings. None of my Rams have ever seen 22 MPG except when coasting down a mountain.

I just finished a 3000+ mile all highway road trip from St Louis to Tucson and back and averaged 17.3 according to the truck computer. When I manually calculated the MPG it's always within a half of MPG of what the computer says, but the manual calculation has never been better than what the computer says. I had a few tanks that nearly reached 19 mpg and a few with a headwind that didn't reach 16 mpg. I'm sure I could have reached 20 MPG with the cruse set on 60 or 65 but then I would have been risking my live as the interstate speed limits were mostly 75 or 80 mph. My readings are typical of every Ram I have owned.

View attachment 174280

Same as he showed in his post that I replied to.

 

[Willwork4truck]

Waste of money, your plugs are fine with just 70K on them. I'm at 67K miles

Not if you own an ecoboost Ferd. They have to be changed by 60K or even earlier. Thank goodness for Mopar.

 

[Scap]

This is my current tank.
35 miles one way to work. Better than half of it is with cruise set at 73mph. About a quarter of the remaining is with cruise set at 57mph, but there are lights every mile or so and the cross traffic causes me to hit most of them. Then the rest is the left/stop/right/stop crap to navigate through the hood to my house.

 

[Willwork4truck]

I will add the place you refuel. Top tier gas vs cut rate station down the corner…
All the usual suspects as has already been offered up.
Certainly temperature is a big thing, just ask the EV owners what their range is during the winter.

I’d take a 5-15% drop using gas compared to their 25-45+% drop in the winter.
Insideevs.com said: (See article dated January 5, 2024, begin quote)
“According to data recently presented by battery health startup Recurrent Auto, which tested a pool of over 10,000 cars comprised of the 18 most popular electric models in the US, EVs retained 70.3 percent of their range in freezing temperatures.

Some vehicles performed much better than average in this respect. For instance, the Audi e-tron lost just 16 percent of its range in winter, making it the best performer of the study. The weakest model from this study was the Volkswagen ID.4, which lost a whopping 46 percent of its range under such conditions.”
End of quoted portion of article.

Oh, 1 last factor, when DW drives, well lets just say she “exercises” the hemi. She said the 3.92 gears are “more spirited” than her 2019’s 3.21.
Now how would she know that? Hmmm.

 

[6of36]

Where you buy gas can make a big difference. My mileage dropped, since my trip home from Mark Dodge. I assumed it was because of the winter blend. I have been getting gas at Costco, because it is "top tier", and usually the cheapest around. My last trip down state, was on Jan 1st, and Speedway had $.24 off a gallon, so I filled up there. My mileage went up 2MPG. I plan on doing this a couple more times to insure it's the gas, and not a fluke.

 

[Willwork4truck]

Where you buy gas can make a big difference. My mileage dropped, since my trip home from Mark Dodge. I assumed it was because of the winter blend. I have been getting gas at Costco, because it is "top tier", and usually the cheapest around. My last trip down state, was on Jan 1st, and Speedway had $.24 off a gallon, so I filled up there. My mileage went up 2MPG. I plan on doing this a couple more times to insure it's the gas, and not a fluke.

Mix that Costco 91 and 87 for a nice 89 octane like RAM wants… I usually fill at 1/2 tank and do that.

 

[BowDown]

I use costco 93 exclusively due to price being cheaper than everyone else and its top tier. My experience has been that 93 consistently gave me 2mpg better

 

[Willwork4truck]

In my state (SC) it is 91, in some states the unleaded is as low as 85 (Colorado). Occasionally I would use Sheetz E-15 88 octane. Couldn't tell you how well it did as I don’t get it unless I visit family.

 

[DEG]

Same as he showed in his post that I replied to.

LOL. Got it. Over the last couple of years you have dropped from 22mpg down to a consistent 14 -15 mpg since the post you referenced listed TWO mpg ranges dependent upon time.

 

[Scap]

LOL. Got it. Over the last couple of years you have dropped from 22mpg down to a consistent 14 -15 mpg since the post you referenced listed TWO mpg ranges dependent upon time.

I don't know what you're saying.