I had a 2000 F-150 XLT Scab shortbed auto with the 4.2L V-6. I now have a 2002 F-150 Lariat Scab shortbed auto with the 4.6 V-8. For me, gas mileage was and is the same for both. 11-13 mpg no matter what or how I drove, city or highway. I had no problems with the 4.2 at all. It was a good engine and I have no complaints about it. After having and driving my 4.6L, it would have eaten my V-6 equipped truck for lunch. As a thought, comparing the price difference between the 4.6 & the 5.4, you can get "more truck" with the 4.6. I got a loaded 4.6 Lariat as compared to a 5.4 XLT for the same price.
But it depends on what you want to do with it. If you want to tow the tower of babel, get the 5.4. If you just want to have a daily driver with some poop when you put you foot in it and tow occasionally, get the 4.6.
The 4.2 V-6 will tow and haul, but it will work quite a bit harder which will result in way lower gas mileage.

 

Get the 8, my 4.2 gets 12-13mpg no matter what, unless its ALL free way w/o towing then I can hit 15-16. The 4.2 with some work will tow (I have intake, exhaust, chip) but it gets about 10-11 mpg towing. I tow about 5-10k miles a year, and I'm definately ditching the 4.2 for either a new 5.4 or a diesel, but if you have a choice, the 5.4 is all around better.

 

I hate the 4.2L that came with my truck. Runs rough since brand new (had 0 miles on it when I test drove it) and has no power compared to the volumes of gas it guzzles. Putting on slightly larger tires made the problem worse. Its the only thing I don't like about this truck.

 

Ok, first you guys need to get a tach. Especially if you have a 5 speed(like me). When I first bought my 2002 4.2l it didn't have a tach.(like most ford trucks ) I thought the v6 was a turd intill I installed my tach. Come to find out the truck sounds like it is running higher rpm's than than it really is. I was shifting at about 3200 racing w/out my tach, and it sounded like the thing was bout to blow up, but that is when you start feeling a little bit of power in these trucks. Now that I have my tach I am way more proud of my truck, I have ran w/plenty of 350 chevy trucks and have beaten a ton of 4.6l trucks and my mods are only dual catback, intake, chip, and tb spacer, so if you don't have the tach get one and then tell me it is weak. If you already have a tach and still think it is weak, nock it up to about 4500 rpm's then shift, if you still think the don't like it something is wrong. These are just my thoughts

-Brad

 

yeah, i have to agree with charles, the truck does sound like its reving higher than it really is. I personally feel that my v-6 has alot of power. and i have driven plenty of fast cars so i know what power is. i have only driven a 97-03 v8 f150 a cpl times so i cant really compare it, but i did alot of driving in a 96 5.0 4x4 and i gotta tell ya that my truck would beat it. cant say much for gas milage as i dont really pay attention. And as for the low end, my truck has plenty, maybe the chip and the manual tranny are to thank. I hear the auto v-6's can be dogs.

gl either way u go