How can I improve MPG on my 3.5L EcoBoost?

I’m getting about 11mpg on the dash with my 2018 T250 and 3.73 gears. I’m looking for tips on how to improve this. I don’t drive aggressively, and my tire pressure is slightly above the normal level.

I have a 2016 350 XLT low roof, long wheelbase. I keep the tires at the recommended pressure, never rev above 2000rpm, and keep my speed to 55-60mph max. I’m averaging 21.3 mpg with a mix of city and highway driving. I do get honked at a lot, but they’re not paying for my gas.

@velmak
Take my upvote for the ‘They’re not buying my gas’ part.

Adrian said:
@velmak
Take my upvote for the ‘They’re not buying my gas’ part.

Same here!

That doesn’t sound right. My 3.7 T350 HD Dually is doing 14mpg.

That’s pretty low. My 2015 T250 medium roof, with a 2-inch lift, 17” BFG KO2 tires, a ladder rack, and full shelving and tools, gets between 12-14mpg. You might want to change your plugs and air filter. I also run 93 octane, which seems to help.

I get about 16-17mpg city driving with my 2016 Transit 150. Are you hauling a lot of weight?

I have a 2023 T250 with the 3.5 EcoBoost 148” mid roof, and I’m averaging between 17-18mpg.

Something seems off. I get well over 20mpg with a similar setup.

My 2019 350HD DRW EL HR with the 3.5 EcoBoost gets 14-15mpg on 89 octane, and I’m in the hills of West Virginia. You must be in Denver or something…

I have a 2023, 150-Med. Roof, standard 3.5L. It’s a loaded work van, using ethanol-free 91 octane. On the dash, I’m getting 19mpg. When I hit the interstate and was cruising at 75-80mph to keep up with my wife, the mpg dropped by about 10 due to high revs and windy conditions.

@Sutton
Ethanol-free definitely helps because ethanol is less energy-dense than regular gas. It’s not always cost-effective, but you might notice a difference, especially in a turbo engine. The octane level also plays a role depending on what your engine is tuned for.

@Sutton
I was getting 19.5-20mpg on a recent run at about 70mph, but the wind picked up and dropped my mpg to 16 until I got out of that area.

What octane are you using? The EcoBoost runs fine on 87, but it does better on 89 or 91/92, especially if you’re hauling weight and need more power. How many miles are on your vehicle? Are you getting any engine codes or burning oil?

@Nova
No codes yet, just got it, and there’s no oil burning. I’ve got 30k miles on it.

I have a 2022 non-EcoBoost, 350 EL HR AWD SRW with 4.11 gears, and I’m getting about 17.5mpg after a 3000-mile test. A lot of it was highway, through mountains, and about 10% city driving. If you can, use the ‘instant mpg’ gauge and try to keep the number as high as you can.

@Gianna
I’ve got 3.73 gears.

Briar said:
@Gianna
I’ve got 3.73 gears.

That should help out. My guess is either you’re accelerating hard a lot, or there’s a mechanical issue.

My 2023 150 low roof with 3 ladders on top, tools, and parts inside, gets around 16mpg. My van weighs about 8300 pounds. My 2018 was about the same, and neither had EcoBoost. Your mpg seems low. Try running a couple of tanks of 94 supreme fuel; it might clean something out.