roconnor2012

Hey guys, I have a 3.7L SuperCab 2WD XLT 3.73 with a leveling kit, K&N CAI, and currently a Hypertech tune. When driving around with just me in the truck and no load, I can't seem to get better than 16mpg. Whenever I go up a hill it seems like my truck struggles as if it were towing, even though it's not. When this happens it also sounds like it is giving a lot of power, but that doesn't seem to translate to power on the ground.

This issue was ongoing before I tuned it and the Hypertech economy tune seemed to help a little bit. Also, it is not the way I drive that affects it. I let my Dad borrow my truck last week just to be sure (he drives with what he calls "the feather touch"). There was no change in MPG.

Any help you guys could give me with this would be greatly appreciated. I know that an accumulation of changes to a vehicle can compound the decrease in MPG, but I feel like they can't be to this extent.

RogueGT

What do you think you should be getting? Remember, every upgrade, stop light, stop sign, drive-thru, slow down and accelerate affect your mileage. I live in the Northeast, very hilly and I am getting 17-18 mpg but my drive is a straight shot to work 30 min each way with 1 -2 miles of city driving the rest is highway with no traffic. I have my cruise set to and from work. In the winter, because I don't set my cruise with slippery roads my mileage will drop to mid 16's as I'm sure my CC is much more efficient at maintaining speed than my foot.
So then ask, is the 3.7L underpowered for the weight of the truck...some might say yes. Whereas the 5.0L and the Eco have sufficient power to make small adjustments in throttle response the 3.7L may have to adjust slightly more? Over-shoot / under-shoot...all effects mileage.

Chrisj

Now I have never done actual calculations based on fuel filled and odometer reads, so this may be not even worth typing. However FWIW the dash average mpg is at its lowest 19.3 to 19.5 and as high as 22.1 or 22.2


Usually reads at mid 20 today its 20.6


For me it seems to get better mileage than my '94 so these numbers feel accurate enough for me, the '94 was getting 18 no matter what up hill towing not towing....very little change just seemed to average out at 18 all the time.


I have never felt the 3.7 was under powered. Even in Colorado when we went to visit my brother in Evergreen (which is even higher than Denver) we packed in the whole family to go out to dinner and she pulled great, not straining, never noticed it staying in a lower than normal gear when it shouldn't have.

zchannel1

FWIW, I live in San Diego county... not much flat ground around here so I'm going up and down hills a lot. 2012 XLT SCrew, 3.73, 3.7L, 2WD, no mods to the drive train or power train.

Driving around town on city streets, typically I get 15-16 MPG
Highway driving at 65 mph, I get 22-23 MPG
Highway driving at 70 mph, I get 20-21 MPG
Towing my 5200 lb boat, I get 14-15 on the highway.
My typical overall mix of driving for a full tank is between 18 and 21 MPG, but typically I'm consistently between 18.5 and 18.8 MPG whenever I fill up.

These numbers are all according to the OSD.

GrasslandHVAC

What size are your tires? What kind of driving, city or highway or combination? What kind of fuel ie octane level ethanol level etc?

RogueGT

All these except the octane level in your fuel will have an effect on your mpg. Higher octane gives better mpg is a giant myth. These myths have been debunked since nearly 10 yrs ago but the public still seems duped.
http://yourcarangel.com/2015/01/myth-high-octane-fuel/

jjjohnson

with my 13 F150 supercrew, I average 17. I have 275/75/18 BFGoodrich, cold air intake and a tonneau (sp)cover.

roconnor2012

I have 265/65/18 Cooper Discoverer ATP's. I drive half city and half highway but usually with traffic (I commute through Atlanta traffic). My MPG used to be better and I feel like I should be getting 17 in my commute.

On highway trips, I can't get over 18 anymore. I used to be able to get 21-23 on the highway but now at lower cruising speeds (around 70, where as I used to drive 75-80) I can't get close.

Also, I only put regular fuel in it so no change in octane.

I think my problem is I bought into the sticker MPG too much when I bought the truck and it has under performed since. Is the general consensus that this is normal due to all conditions involved? I appreciate all of the feedback and opinions.

RogueGT

Agreed with the sticker MPG thing...I try not to buy into that too much but realize everyone's ride is different and everyone's truck is not the same. Slight differences in build, manufacturing and the fact that we're dealing with mechanical devices means everyone's will be somewhat different...even if the model is the same. Hence, they give you an average mileage but realize some could be lower and some higher.

GrasslandHVAC

What kind of mileage are you at on the odometer? Maybe truck is coming up on some maintenance it needs?
Yeah the sticker fuel econ is a rainbow unicorn, I have never been close. I seldom see 17 MPG in my 3.7 4x4, and that was with stock tires. I just went up to 235/80/17 bfg AT ko2 so waiting to see what it does to fuel econ.
Weight makes a big difference, I run payload every day. And stop and go is a killer on these.