My truck as posted above is:
09 ram 1500 SLT 4x4 crew cab, now 2000MI, don't have the 20" wheels, I believe I have a 3.9 rear gear.

I used to be able to get 18 MPG on highway at 73MPH and 16.7 at 80 MPH. Now I get 15 at 73 and 13.8 at 80mph. Around town it's dropped 4 MPH. My tires were low during that time when I was getting better MPG too! I baby the heck out of it and on highway this morning over 15mi's I got 16.5 at 64MPH. Way down from where I was. I haven't towed or hauled anything yet.

How can a brand new truck drop 4 MPG (same highway route, same everything except now more air in the tires)? I've heard of bad MPG during first 5k mi but 4MPG?????????

 

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Troyolson92, my best guess for your delema is the cold air. I ususally lose about 100kms per tankfull in the winter months.

Patrick, your yellow truc is just amazing!


Dario

 

I talked with some injector specialists from both the Diesel side and Gas side and their one repetitive statement was "Keep your injectors Clean"

When I got this toy it had been sitting for a while, so after half a tank I put together a tank cleaning cocktail I have used in the past, 1 bottle of Gumout fuel system cleaner, a measured amount of Stabil, a large bottle of injector cleaner, a large bottle of heet, and filled up with regular shell and then drove it down to a quarter of a tank. I did notice a marked difference from the day I picked it up and after the cocktail.

I I normally add a bottle of fuel system treatment once a month in the winter
and every 3 months the rest of the year.

 

I know that once they switch to winter gas here in VA that my mileage typically drops some.

 

I was getting 17 to 18 in the summer months and now average 14 to 15.5 in the winter. I also owned two Fords the 4.6 and the 5.4. They both averaged in the winter months 14.5 (4.6L) and 12.6 (5.4L) best and in the spring around March it starts to get better, then they would get 16.5 for the 4.6 L and 14.5 for the 5.4 driving regular. You will not get better gas mileage with the Fords vs the Dodge especially with the 5.4. They put some type of additive in the winter months to control the higher exhaust emission coupled with the extra exhaust from our heating furnaces. I think it's a bunch of bs but what are we to do?

 

Disregard

 

I appreciate y'll trying to help figure out why I dropped 4 mpg after the 1k mi mark. I'm now at 2500mi and it's calling for an oil change. Usually I go 5k mi. Do you guys suggest getting it done now or waiting till 5k?

i'm hoping an oil change and some fuel additive will change my gas mileage back some. I'm sure exactly what gear I have. I believe it's 3.9. How do I find out? What it comes down to I drive about 700 mi. per week and 4mpg drop is pretty big. The last three days on the highway I've average 65mph (in a 70mph speed limit) and the truck says I'm averaging 14.1mpg. I reset it, the mileage, the timer (incase they're connected somehow). 14.1 in 23 degree weather. same trip 1000mi's ago I was getting 18.6 (my personal best). If there's anything else you can think of let me know please.

I will post after fuel additive before/after oil change to see if it makes a difference.

I will post mpg after an oil change (which I can't get to for a couple days and another 500mi's). see if it makes a difference.

I'm also going back down a little further south where it's 5-10 degree's warmer. I'll post then as well to see 'how much' the weather affects mileage. I agree with the poster about weather decreasing mileage. I must have an effect as my mileage seems to drop as the weather does. But I'll make sure and chart the differences per degree and post actual results so we all know the exact difference, at least for my truck setup.


09, SLT, Crew, 4x4, not the 20" rims, 2500mi's, i think it has a 3.9 gear, tire pressure is at 38 all the way around.

 

The cold temps are going to make a huge difference...period.

I get about 16 driving around here when it's warmer. I'm down to about 12 now with the colder weather (sub zero). You just can't expect to run high mileage when it's cold unless you do long trips without cold starts.

I've had the truck only a short time and have had the computer up to 19.6 so I know everything is working ok.

My silverado did the same thing in the cold. 16-17 summer. 12 winter.

 

when did you change your oil the first time? What interval do you change it now?