Ok I am rebuilding a 2000 f150 well actually I am taking 2 and making 1. they are both reg cab short boxes. Long story short It will be 4x4 red cab step side box, my question is I have a 4.6 and a 5.4 sitting in my shop. The 5.4 has 121,xxx on it and the 4.6 has 165,xxx on it. both run great and have good oil pressure. the 5.4 has PI heads where the 4.6 does not. I would like good milage out of the truck but in a sporty little truck like this power would be fun to. What mpg differences are there really between these 2 motors? Is the power difference really that noticable? just a few questions I had and would love the input for the experts on here! thanks guys

 

deffinitely go with the 5.4.

the mileage can be alittle better with the 4.6.

the 5.4 has a ton more options

 

Power difference is very noticeable, gas mileage difference is negligible, it's gonna suck with either motor.

 

5.4. its the only v8 they should have offered in these trucks. its the only one that gets out of its own way as good as a full size truck should, and hauls pretty decent loads.

 

I was thinking the 5.4 was the way to go but I will be driving and comuting way more then pulling somthing so I was woundering if the milage of the 4.6 would be to my advantage. I saw somewhere that the 4.6 without PI heads get 3-4mpg better then the 5.4. Is that really the case?

 

I believe with either motor your gas milage is gonna suck after all it is a truck I average 13mpg with a 5.4 each tank has some towing on it so not sure of unloaded mpg.

 

I have owned both. The 5.4 got a best of 17.5mpg. The 4.6 got a best of 22.3 mpg. 5.4 combined avg 12-14 mpg. 4.6 combined avg 16-18 mpg. Never got less than 15mpg with the 4.6, As low as 9 with the 5.4. Same driving conditions. 75 miles farther on a tank of gas with the 4.6 Less power with the 4.6 but the mileage difference would add up if your comute is significant. You will have to decide whether you want the power or the fuel pump savings

 

Most people wouldnt even be questioning this.....5.4

The 4six is a weak motor at best. Milage difference between the two...pfft.

/thread.

 

I had a 4.6 and a 5.4, actually get better milage in the 5.4 Screw than I did with the 4.6 SCab. my .02.....go with the biggie.

 

My 1999 reg cab short box came standard with the 4.6L (Lariat)

I paid Ford an extra $1200 to upgrade to the 5.4L

There aren't too many reg cab short box 5.4L out there.
Most all were all built on customer order.

 

the mileage difference OEM is like what? 1 mpg? its like the v6 mustang getting 1 or 2 mpg more than the v8... i'd take the fun factor over the minute mileage gains.


the other problem is, why the hell would u commute with a truck?

 

5.4L... You'll only be kicking yourself later if go with the smaller engine when you could have went with the larger one.

 

people are always ragging on my 4.6 haha audis 4.2 is one of the most powerfull v8s in the world... but yes definitly go with the 5.4, my mothers 5.4 in her expedition is noticably slower then my 4.6 but i think her truck has different gears and a buddy of myn has a 2006 f150 with the 5.4 and i walk all over him all day so.... but the bigger the better they say