engineermike

Rick, of course there are many reasons economy gets worse in the cold. However, saying that "the engine acts bigger so it uses more fuel" or "the air density is higher so it needs more fuel to match" are simply incorrect unless you drive around at wide open throttle all the time.

Unfortunately, the explanation is more complicated than that. Engine power is a function of intake manifold air density. Its the speed-density theory of engine operation. When the temperature drops, the pressure must also drop in order to achieve the same power/acceleration/speed. Lower pressure means a deeper manifold vacuum. A deeper vacuum means that the pistons are pulling harder on the intake stroke, which sacrifices power for any given amount of fuel used, thereby hurting engine efficiency. Not sure if I can state this any simpler.

Pandaz3

I certainly enjoy Mike and Rick's banter. It is educational to me. I'm still going to get a tune and see what that does for me.

littlebigtruck

Do not know why (science and stuff can explain it) but i do know that mpg falls in colder weather. With my 2013 F150 XLT 5.0 i'm getting about 16.8 mpg mostly 60-70 mph... It will be better when it gets warmer

Fastskiguy

I'd love to hear how it works out, sure appreciate it if you can update this thread after you get the tune. The only issue might be teasing out the temperatures….these polar vertices are raising hell with my mileage log LOL.

Alweeja

Did the bed cover help any

Burgandy

Thanks for the info, I had no idea the EPA tests were done on a dyno. It's odd that they offer MPG estimates at speeds that no one in the real world uses. Controlling the environment makes sense from a testing perspective, but those speeds are unrealistic... where I live its more common to 50 MPH in the city than 20.

HardcoreOffroading

My 5.0, if im not late and driving 45-50 im getting 17 mpg in city and 20-21 on the highway. But when im driving with my foot on the pedal the whole time and making quick stops etc, im gettin exactly 15.

Ricks F-150

Why can't people understand, that no one can possibly take every single driving scenario into account, when they decide what to rate a vehicle's mileage. I never expect to get the sticker mileage.

Alweeja

Gotcha

mcpa850

Ok I read some of the articles here but none seem to answer the question I have when it comes to gas mileage for me. Long story short, I had a 2012 F150 FX4 (loved it by the way) but traded it in on a 2013 F150 FX4 because the deal was too good to pass up. Both have the eco boost engine (awesome engine by the way)

That being said I am the one that drives the vehicle most of the time (the wife occasionally will drive it). Both trucks are almost identical (almost) and yet my mileage is so different.

Since I am the one that drove both trucks it would stand to reason that I would be able to get the same type of gas mileage out of both of them. However, I can't and it drives me nuts. So I'm wondering if anyone has a solution for me that they have tried.

The problem is in my 2012 truck I averaged 18.5 miles to a gallon (both city and highway combined). In the 2013 truck though, I'm lucky if I can average 15.5-16 miles to a gallon! Huge difference.

The 3 things that are different on the 2 trucks are as follows:

Different items - 2012 - 2013
Tire Size - 18inch - 20inch
Sunroof - NO - YES
Tail Gate Step - NO - YES

Ok that's it. Everything else is the same, engine, gear (3.73 by the way) FX4 Crew Cab.

I'm a creature of habit so I pretty much do the same stuff, so I drive the same places pretty much (work, kids, etc). I just can't imagine that 20 inch tires, sunroof or tail step can make this much of a difference.

Any suggestions would be appreciated. I've made no mods to the vehicles. And the gas mileage I claim is basically from day one, with little change after the break in period. I'm just baffled.