2009 5.4 XLT Reg Cab Long Box 4x4 3.55 Limited Slip 7200lb
2011 5.0 XLT Reg Cab Long Box 4x4 3.75 Limited Slip 8200lb

Fuel Mileage on the dash 18L/100km with the 5.4 which is reading low cause if you figure it out yourself its 19L/100km!
The 5.0L reads 14L/100km on the dash and will need to be checked out cause its going through more gas then that I'm sure.

The 5.4 does have aggressive Load range E 265/75/16 tires
The 5.0 has the factory not so agressive 245/75/16 tires

The 5.0 likes to be reved and reved high! it revs higher then the 5.4 but it doesn't give the feeling like it will last for high milage like some of our past 4.6L and 5.4L to bad the 6.2 wasn't offered in the XLT

Anyone notice a oil drop in there 5.0?

 

One more time, in English this time?

 

I'll second that

 

A 5.0L engine with lower gears uses more fuel than a 5.4L engine with higher gears. This seems like an expected outcome.

The one concern might be the possible oil consumption or loss in the new 5.0L.

 

18L/100Km would be around 13mpg
14l/100Km would be around 17mpg

So the 5.0 is getting better FE