Bad Gas Milage

Brady18 · Apr 10, 2015

So, I just got a new truck a couple of weeks ago. I put a leveling kit on and then added new wheels and tires. I have the 3.92 gears. I knew adding the new tires would decrease the gas mileage but it has been pretty bad. I went with 295/60R20 Nitto Trail Grapplers. I am getting 12 miles per gallon. Seems kinda bad. I am not gunning it or anything like that and drive mostly country roads with stop signs every mile or so.

Anyone else have a similar set up and what mpg are you getting?

scubasteege · Apr 10, 2015

That seems pretty standard for a 35 inch mud terrain tire. A stop sign every mile is quite a lot of stop and go which is probably why its really low. Every time you stop even not gunning it the truck still works harder to get back up to speed only to stop a short distance later and do it all again.

xrsman · Apr 10, 2015

Brady18 said:
So, I just got a new truck a couple of weeks ago. I put a leveling kit on and then added new wheels and tires. I have the 3.92 gears. I knew adding the new tires would decrease the gas mileage but it has been pretty bad. I went with 295/60R20 Nitto Trail Grapplers. I am getting 12 miles per gallon. Seems kinda bad. I am not gunning it or anything like that and drive mostly country roads with stop signs every mile or so.

Anyone else have a similar set up and what mpg are you getting?

Well it sounds like you're doing a sort of "in city" driving with all those stop signs. The truck should break in at 10,000 kms and get you a little better mpg. Expect to get maybe 1 better when that happens.

The best I've seen with my 35's (your tires are the same weight so it's an accurate comparison) is 20 mpg US. I was doing 90 kms on cruise for a few hours without stops. On the return trip I got 18 mpg US. These were both hand calculated with fill ups right before each test, so 100% accurate.

Typically I average between 14-16 mpg US highway where I live. It has dipped down to 11.5 mpg US when I was using a lot of remote start and only driving back and forth to work (3 kms away)

Bottom line, get used to the ****** mileage and just appreciate the awesome truck you're driving around in! Lol

If you want to help improve it now here's what can help: Diablo tuner with hemifever tune (I run 91 octane) S&B cai, catch can, new exhaust (I went with an MBRP cat back).

This will also greatly increase your power and "smiles per gallon" lol

6.7CumminsDrvr · Apr 10, 2015

Didn't see a tuner in your sig, so have you recalibrated your speedo? If not your MPG will be off due to incorrect mileage.

Brady18 · Apr 10, 2015

I have not recalibrated. Thanks for that heads up. I realized it would affect my mph but never stopped to think it also affects the mpg. I feel like an idiot. I guess it is time to get a tuner. My wife will be so "happy". Hey, a need is a need right?

I am not too upset about the low gas mileage as I was prepared for bad gas mileage just thought it would be a little better.

Thanks everyone for the responses.

6.7CumminsDrvr · Apr 10, 2015

No worries man! Thankfully I had my tuner from my '12 and didn't have to buy a new one! I'm guessing you won't see a HUGE improvement but you will see some.

MADDOG · Apr 10, 2015

A programmer will help as will a programmer and freer flowing exhaust.

The 3.92's on 35's will put you down on power a bit so the truck is working harder to do the same things, i.e., move from a stop, accelerate, etc...so that's tough on mileage as well.

And it's fairly new so the mileage is gonna be less than what it will realize after it gets some miles on it.

Programmers, such as what is available from DiabloSport (one of my preferred HEMI programmer makes) will take some time to catch up with the new model year but they are worth it, IMHO, down the road.

My old 5.7L powered MegaCab really woke up with a Predator, custom tune, intake and exhaust. My SRT8 also has a Predator and custom tune. It turned into a beast.

I will be doing the same sort of things with my 2014 6.4L powered truck as my experience with those mods has been very, very good.

In your case, your truck just needs a bit of "enhancing" as a "need is a need", right?

Brady18 · Apr 10, 2015

So I noticed there are two main tuners through DiabloSport. One is $450 (InTune Programmer) and the other is $600 (Trinity Programmer). What are the big differences/capabilities?

xrsman · Apr 10, 2015

Brady18 said:
So I noticed there are two main tuners through DiabloSport. One is $450 (InTune Programmer) and the other is $600 (Trinity Programmer). What are the big differences/capabilities?

Tuning wise they're exactly the same. One won't give you more power than another. The intune just plugs in and you unplug it when you've installed the tune. The Trinity can be left on all the time to be used to monitor the engine, race mode, etc.

I have the Trinity because personally I like to have the ability to monitor the engine for knock or what have you. Plus it makes it easy to see your 0-60 numbers.

Size on dash (not in the way at all)

Main screen

Knock monitoring screen

Brady18 · Apr 10, 2015

Thanks.

arod412 · Apr 11, 2015

My 2012 gets 10-11mpg in city driving, so that is to be expected. On the highway, i can see it climb to about 16-18mpg even a little more on long drives, and i still have my stockers tires.

Truck name: Rampage
2012 Dodge ram 1500 Quad Cab Big Horn 4x4
*Bilstein 2.8" front
*Bilstein shocks on rear with 1" spacer
*Pioneer AVH 4300DVD head unit
*Polk Audio Dxi350 dash speakers
*Kicker 40CSS654 6 1/2" door speakers (x4)
*fox box 2-12" speakers holder for rear seats
*2-12" alpine subs (swe -1243l
*500 watt alpine mono sub
*LED 3rd tail light smoked
*Spyder LED smokes tail lights
havent even started on the engine..lol

doz · Apr 11, 2015

I get about 12 with my NTG's as well. Pretty normal. What were you expecting turning a larger tire that weights quite a bit more? I think the tire alone weighs what the factory wheel+tire weigh.

Informal · Apr 12, 2015

Not to hijack.. But the dealer can fix the speedo for larger tires right?

I had my lift and 35's installed by the dealer, and my speedometer is dead-on.

Brady18 · Apr 12, 2015

doz said:
I get about 12 with my NTG's as well. Pretty normal. What were you expecting turning a larger tire that weights quite a bit more? I think the tire alone weighs what the factory wheel+tire weigh.

My dad has pretty much same truck with stock tires and gets about 15-16 city. I knew these tires would reduce mpg's just wasn't thinking 3-4 mpg's. I am not upset, don't get me wrong, I would do it again just a little surprised at the decrease in mpg's.

doz · Apr 12, 2015

Your dad has the same truck with 35x12.5 getting 15-16 in the city? What type of city driving?!?!? Even the manufacturer rating is 16 under the BEST conditions...

Do not always believe what everyone claims. One persons city driving can be 45mph streets with little to no traffic while another persons city driving is stop and go below 35mph. There is a lot more to factor in than people realize.

Im sorry, but there is no way a truck w/ 35x12.5 is getting 16mpg in the city.

xrsman · Apr 12, 2015

doz said:
Your dad has the same truck with 35x12.5 getting 15-16 in the city? What type of city driving?!?!? Even the manufacturer rating is 16 under the BEST conditions...

Do not always believe what everyone claims. One persons city driving can be 45mph streets with little to no traffic while another persons city driving is stop and go below 35mph. There is a lot more to factor in than people realize.

Im sorry, but there is no way a truck w/ 35x12.5 is getting 16mpg in the city.

He said he dad had stocks lol. Very true what you said about the different types of city driving! I'd consider mine city driving but I'm in the country, drive 3 kms to work and never get above 50 km/h! To others it could be 40 mins in stop and go!

doz · Apr 12, 2015

Errr, ninja edit? Lol, when I first read it I did not see stock tires.

15-16 with stockers is believable. Im sure though that 1-2 of that is also due to his foot being lighter than yours

And IMO, if you drive in the country with limited to no stop signs/signals, it does not matter if you drive 35-40mph it should still be considered highway IMO. City designates stop and go traffic, not so much speed as you can get very good MPG at 35-40mph.

xrsman · Apr 13, 2015

doz said:
Errr, ninja edit? Lol, when I first read it I did not see stock tires.

15-16 with stockers is believable. Im sure though that 1-2 of that is also due to his foot being lighter than yours

And IMO, if you drive in the country with limited to no stop signs/signals, it does not matter if you drive 35-40mph it should still be considered highway IMO. City designates stop and go traffic, not so much speed as you can get very good MPG at 35-40mph.

Well I stop a few times in that couple kms. Plus for half of it you can't go over 20 km/h. With just going back and forth to work I average between 18-20 L/100 kms (12-13 US mpg) Definitely
not highway driving lol

preachp · Apr 13, 2015

Hi brady18,

Get your speedometer calibrated for the new tires. You are reading about 10% low and that will bring you up to about 13.2 mpg.

preachp

BigDaddyRam · Apr 13, 2015

I have a level with stock tires and rims(for now). But I notice I get really crappy gas mileage with certain brands of gasoline. My truck, the last two trucks actually, prefer Shell. I don't know what additives they use compared to other brands, such as Valero, Exxon etc...but my trucks prefer Shell. I run the 87 octane with no issues whatsoever. I get around 22mpg on the highway and 17.5 in town. Hand calc'd not the lie-o-meter on the dash.

Bad Gas Milage

Member

Senior Member

Senior Member

The Dude abides………

Member

The Dude abides………

Out Exploring Arizona

Member

Senior Member

Member

Senior Member

Senior Member

Senior Member

Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Similar threads

Forum statistics

Share this page