Fuel Economy

[HagleWelding]

I just had the catalytic converters replaced at the dealer after months and months of waiting for them to show up. They’ve been plugged up for a while, causing awful smells and poor fuel economy.

Now after the replacement, and I assume any update to the ECU since the last time it visited was October 2021, I’m averaging around 10mpg. I am babying the truck and cruising a highway back and forth from work maybe 5 or so miles.

Full disclosure, I just purchased the truck a month ago from my dad. It’s on 37 KM3s as well.

 

[Bozz]

Welcome!

 

[FordTechOne]

These trucks are rated 18 MPG Highway stock, with those tires (40’s?) and the aerodynamics of those front end mods, I could see that decreasing drastically.

What’s been done to the engine? Cats only clog up due to poor quality fuel or overheating, which is typically caused by over fueling or a misfire. So if the root cause has not been determined and corrected, it will happen again.

 

[StangGT5]

37s and 10mpg go together like ham and cheese.

Maybe ask the dealer to perform an adaptive reset, or get a better tune. Others on 37s will be more knowledgable, but it's not uncommon to get 10-11mpg on 35s if you're having fun.

 

[thatJeepguy]

Beautiful Raptor and Gshorthair!

 

[Blown00gt]

With the aftermarket intercooler I assume you have an aftermarket tune on it?

 

[isis]

Anyone ever update the ecu with the bigger tire diameter.

 

[Zeusmotorworks]

Not only do you HAVE a tune, but by WHO?

 

[dillard09]

I have 37s and I get 13-14 on the highway at 75. But I find myself driving in 9th gear due to when I'm in 10th it will want to downshift at every incline. So I just lock it out in 9th then it will down shift to 8th if need. I actually will manually downshift to 8th if I see a nice incline coming up instead of letting the truck try and pull the hill, bog down a bit, lose 2 mph and then down shift. Town and highway driving im closer to 11. But with the E-juice im at 8-9 but so much fun. Haha

 

[Muchmore]

Wow did your dad screw you with that lemon......