Why is my mpg so bad around 14-15?!

I live in Chicago and i’ve tried a bunch of things to improve the MPG on my basically stock, V6 4x4 truck......I’ve driven like a granny, raised my tire pressures, checked the diffs and AT and TC fluids, checked that the driveline/wheels aren’t dragging, installed a tonneau, removed the air box charcoal filter, etc.
After all that, IMO my MPG still sucks and hasn’t improved much, even on long highway trips (*Disclaimer- I don’t have the time or patience to only go 60mph for 8+hours)
It’s still a great truck and I love it so i’ve just learned to live with the low MPG for now. Gonna buy OV Tune eventually so maybe i’ll gain a bit more......

 

My stock OR MT is getting 18. Sticker says 19.

 

You just need to drive farther. 10 miles into my commute my scangauge is telling me about 15mpg, by the time I get to work it's 20. Pretty typical for winter.

 

Wow, I thought my 3/4 ton gasser truck was a total pig, 12 mpg. Some of you guys aren’t very far off that. Bummer, drag, seems to take some of the luster off the smaller truck equation. Can’t change the size if that’s what fits, but a full sized diesel gets 25 mpg unloaded, and stock.

 

Well there’s your issue. You aren’t going to get good MPG’s with short trips, especially now that it’s winter. Your truck has to be at operating temp before you can expect anything decent. I use to live close by to work as well and would get 11MPG on my way there because my truck would barely get to operating temp by the time I got there in the winter.

 

Probably running the windshield defroster as well.

 

While I have a 10 year old 2nd gen that is suppose to get 1-2 MPG worse mileage, I get an average of about 17-18 MPG with both city and highway driving. I'm pure stock but literally drive 80 MPH on the freeways with the rest of the traffic everyday. I also live in the mountains so I go up and over good inclines. Big tires, lower pressures in cold weather, extra weight on/in truck, lifted with a higher drag coefficient, oxygenated winter fuel (3% loss of energy), more stop and go during storms, idling to warm it up in the winter, etc., all contribute. Assuming a 20 gallon fill-up, 2 mpg will cost you about 2 gallons of fuel more each fill-up. For me that's about $6 a week. I can handle that.

 

14.5 is what I average for city driving with this 11 year old pig.

 

I get 20.5 hwy and 18 city right now. E rated Bfgs and MT. Not bad at all.

 

The truck will barely reach operating temperature in 10 minutes. That can cause worse milage, especially in colder weather.

 

I'm seeing 15-17 mpg now with the winter blend fuel, longer cold car starts, cold air is less efficient also. I live and work in town, so tons of stop and go, most times i never even make it to 3rd or 4th gear before stopping again. When I have long stretches of road and highways i get 18-20 in the winter, 19-22 in the summer.

TL: DR- OP, its not unusual to see what you're seeing in the city.

 

I've also found significant gains in mileage by keeping the speedo under 70mph, and even more when driving at 60mph. Drag is a function of velocity being a squared term afterall...

 

Lol these trucks drag pretty fuckin hard man, I can tell from all the wind noise around 80 mph

 

I agree with this. I know my MPG based on MPH at this point almost. When I go 60-65 I can get close to 24. 65-70 is in the 20-22 range. 70-75 I'm usually in the 18-20 range. And it just gets worse from there with anything above 75 I'll get no more than 17.

 

Lol, reminds me of a time i was driving against a strong wind on the HWY going home going 80-85 in the winter, i was getting about 13-14 mpg.

 

just a thought, but any chance it's in liters per 100 km? that's about what I get in winter here in Canada...

 

I noticed that passing someone the other day. 85mph in this truck sounds like 145 did in my Camaro.

To answer poor OP; it could be due to bad sensor making you run rich, bad gas, lead foot, a bunch of stuff. I get 18-20 but I drive like an elderly person most of the time

 

city mpg is not the same as highway driving mpg!

 

My FJ’s suffered the same mpg’s till I replaced the thermostats.
(I don’t think they ever warmed-up enough)

 

Even when I drive 65 I never approach even 20mpgs, and I barely use the breaks. I'd say its 85% highway. Best I've done is 18.9mpg on the flat.

The only thing I have are sliders, and E rated tires at 265/70/R17 I believe.