737jet

You'ld think it would. My xlt came with factory 17's. I slapped on some 20's from an older 07 fx4 with some 32x12.5 20's and side by side, they were the same diameter. Typically , factory rims regardless of rim size end up being the same diameter , requiring no speedo calculations like in my case because of a taller / lower profile tire

vmpv

Were that to be true... My 2013 truck came with factory 20" and I purchased 17" rims and winters directly from Ford and they can't adjust the speedo for the difference. Definitely a lower stance to the truck with the winters on. Feels like I get a new truck in the spring when the 20"s go back on

Bill_The_PA

Putting bigger tires doesn't necessarily mean better MPG in practical terms they should be heavier. However with the Ecoboost and it's lower torque curve. I'd expect 20" with proper calibration to perform well. Rolling Resistance (RR) is another factor. I've read up to 20-25% increase in fuel Eco with a tire with excellent RR. Just some food for thought. No matter the choices we make their will some trade off when it comes of tires.

737jet

So, the truck has just past the 3000k mark yesterday and the time came to fill er up. This tank I'd venture to say is about 60% city, the rest highway. Also, I'd like to add that I had given up on driving it like a bit(h this time and didn't hesitate to pin it here and there. I got 610 k from 107liters. It's improving from my last few tanks Wich means that some of the 5.0's do require a break in for the engine to see better economy. Either that or the reset ford did helped. The gauge was just starting to creep into the red and the DTE was 89k to empty.

Alex Founygine

380KM for 100Litres. 23/24L for 100KM. 6.2 with internals 5.13 gears

737jet

Nice Raptor!

Update:

The truck has just under 4000k's on the odo. Back when I bought this truck, sometime in October, I got 520k's from 110 liters, most of that being freeway.

I filled up today and got 560k from 103liters, the fuel gauge was nowhere near the red . That's 100% city.

So she's getting better with age. Meaning these trucks DO need to be broken in. That story of the engines being broken in at the factory feels a bit far fetched. Glad to see the numbers improving. Still not there yet, but pretty sure she'll get there.

Azzurri

I'm averaging 15-17L/100k with my 5.0, probably 70% city driving. But my commute changes fairly regularly so it's tough to gauge it accurately.