Hey,

Backstory:
Bought my truck back in Sept 2012. Its a 2012 F150 FX4 screw, 5.5' box, 3.73 axle. Put 20,000km on it since, and for the first 15,000km, my average fuel economy was 13-14L/100km (17-18mpg) on the highway (120kmh in the prairies) (I only have it in 4x2 for highways, never 4x4). This winter, after a really cold snap (-40C, -40F), my truck struggled to start. Let her warm up for 15mins or so (She was plugged in all night). I went on a 700km round trip (350km each way) and averaged 19L/100km (12.5mpg). I thought maybe this mileage was just due to the temperature, however, since this trip, I haven't been able to get under this 19L/100km. Last week it was -4C (25F), and I went 350km round trip and got 19.5L/100km (12mpg). So I know its not temperature (maybe a slight factor, but not the source) or wind related, as I had 2 round trip day trips to compare with. For another number, when I towed two sleds on an aluminum trailer yesterday (weighs less than 2000lbs), I got 21.2L/100km (11mpg).

Current:
Phoned my dealership, and asked them to have a look at it (As they are also doing an oil change on it). It goes in Wednesday, however they informed me that for issues involving bad fuel economy, if the computer hasn't flagged an issue, there is nothing they can or will do about it. Also, if the computer doesn't flag an issue, none of the work done previous or future will be covered under warranty and will all have to be out of pocket. Oh, I also asked them to look at my dash because it is squeaking so bad you can hardly stand to be in the truck, but they said that is normal fatigue and they won't look it at. The driver window also rattles and drives me nuts, but its no where near the squeaking for noise level. I've rammed material around the edges of the dash now just to quiet it. Makes me immaculate truck look like its been abused since day 1.

Does anyone have an idea what could be acting up and causing this poor mileage? Perhaps the fuel pump got damaged and isn't regulating right? O2 sensor out? Intake temp out? I don't have a garage so it is very difficult to troubleshoot myself in -5C to -30C weather. I cringe when I look back to the pictures I took when I had done my first road trips on this truck, filled her up while at 13L/100km average, and had my to-empty number reading at 999km for a while. Now I can't fill up and have it estimate above 700km range.

Also, is this typical practice for ford service at ford dealerships? When I phoned them I expected them to be very accepting of my concerns and want to troubleshoot it, but it just sounds like they are going to blow it off as a whatever. If thats the case, this truck is going to be traded-in for something else. Love my fords, but for a first new vehicle, I have not been impressed.

Thanks in advance for your responses.

 

Well have you ever tried running some fuel injection cleaner through your truck? It could be something as simple ash a partially plugged injector.

 

I was told its within normal limits when I made a similar complaint about my 12.5mpg numbers. Turns out I had (at least) a misfire in #8 which was below the cel threshhold so we'll see what happens with the new plugs.

Fwiw low end torque is much better and all plugs came out way over gapped with the #8 showing much blacker coloring than the rest.