Getting Terrible Mileage. Any Ideas?

I picked up a used 2021 Expedition with 40k miles. I’ve driven about 15,000 miles since, and I’m only averaging 12.5 mpg. The majority of my driving is highway, and I drive like a grandma. I’ve already changed the plugs and cleaned the intake sensors, but it didn’t make a difference. Any suggestions on how to improve the mileage?

You’ve never seen my grandma drive! She’d give a Nascar driver a run for their money! Seriously though, I have a 2018 Expedition and get similar mileage. I think it’s because my wife idles a lot while waiting to pick up the kids from school. I tried premium fuel, but all I could find around here has ethanol in it, so it didn’t make much of a difference, plus it’s an extra $1.50 per gallon.

That sounds pretty low unless you’re sitting in a lot of traffic. I live in a rural area and get around 17-18 mpg.

Same here. We have a 2022 Timberline and average 17-18 mpg, mostly rural and highway driving.

I’ve got a 2022 Timberline too and get around 16 mpg, with about 60% city driving. I do have a heavy foot though! I also only use 93 octane fuel, usually from Quik Trip or Sam’s Club.

I’m in rural North Dakota, as rural as it gets.

Maybe try hand calculating the mileage? I noticed the displayed average on my dash is stuck at 16.5 mpg no matter what, but when I reset the trip meter, it shows better mileage depending on my driving. If the display is accurate, though, maybe there’s an issue with the engine, drivetrain, or brakes.

I’ll give that a try, but I’m pretty sure the reading is within 1 mpg.

Stop-and-go traffic burns a lot of fuel, and so does driving above 80 mph in these big vehicles.

I have a 2021 with the 3.5 Ecoboost and had the same issue. I recently went on a road trip, and a friend asked why my mileage was so bad. I didn’t know, I drive carefully and still only got 12 mpg. When I fill up, the DTE shows 218 miles. My friend suggested using premium fuel, and after trying it, the DTE jumped to 364 miles. Premium fuel made a big difference for me.

I have a 2020 Expedition and run regular fuel, but I average around 18 mpg with a mix of highway and city driving.

Try using adaptive cruise control more often; it usually helps my mileage. Also, run some Chevron Techron Complete through the system and see if that helps.

Are you driving in 4WD? My 2019 does much better than that. The sweet spot for mpg seems to be around 60 mph, but that’s hard to keep on the highway. I get about 18 mpg at 80 mph, sometimes better if it’s flat. Towing brings me down to 12, but that’s expected.

My brother has a 2019 and averages 18.5 mpg. He lives across the street from me.

Weird that the newer ones aren’t doing better. Maybe there’s something wrong—brakes dragging, bad bearing, not shifting into 10th gear, or you’re in sport mode too often?

I have a 2022 Limited Max with the 303a Stealth Package. On long highway trips, in eco mode, and driving near the speed limit, I get around 8.5L/100km to 10.5L/100km depending on the terrain. The vehicle has almost 80,000 km on it, and everything is stock. It also has the max tow package with a 3.73 rear end.

My 2013 5.0 gets around 10.5 to 12 on similar trips. It’s also stock but has a 2.5-inch lift and 275/60/20 Duratracs on it.

Can you convert that to miles per gallon?

Sure, 8.5L/100km is about 27.7 mpg, and 10.5L/100km is around 22.4 mpg.

I’m sitting in my 2021 Expedition XLT right now, and I haven’t reset the trip computer in a while. We live in rural Arkansas, so we do a lot of short trips and highway driving. I also sit with the engine running sometimes. Right now, I’m getting 19.3 mpg.

My 2015 with the 3.5 EcoBoost gets around 18-19 mpg in rural driving.