Remember though that the 2001 4.6's are PI - Power Improved engines. I believe there is a trade off between the power and the fuel mileage.

I drive a '97 Romeo 4.6, and I have averaged exactly 17 mpg over almost five years now. My driving is about 50/50 freeway and city miles. I'm not going to complain! Freeway mileage at 70-75 mph is nearly always over 20mpg, with my best over 23 mpg. Winter driving is what kills my overall, as my mpg drops into the 14-15 mpg for at least two months every winter. Oh what fun...

I'm sure for the average user the 4.6 is just fine. Oh I know, whats an average user...

 

I have had both, 5.4 gets by vote. On the open highway I could not tell more that 1mpg difference, course I drive at about 80. The 4.6 just lacks low end grunt badly.

 

well if you are going to tow something like that I would get the 5.4 liter and the biggest gear ratio. And probaly the towing or off-road package whatever they have.

 

I went with the 4.6 only because I can't stand automatic transmissions. The 5.4 only comes with the auto tranny. Bigger is better and I would have gotten the 5.4 if it came with a manual tranny.

 

I am currently shopping for a SuperCrew, and am having trouble deciding between the 4.6 and the 5.4
I've driven both and the 5.4 is IMO better suited for this truck, but the reliability issues of the 5.4 make me think twice.
It just seems that when a member with a 5.4, posts an engine problem, there are loads of other people that reply with similar problems. When someone posts about a problem with a 4.6,
there doesn't seem to be the same hoard of members complaining about the same thing. Piston slap aside, does the 5.4 still have chronic problems like the rough idle, etc, etc..?

 

My experience with my 4.6 has been nothing short of exceptional. I have had no problems to speak of and the engine does what you ask it to do without any major problems. The other posters are also correct. Get the 5.4 if you tow alot of big loads or if you just want the extra power for highway driving . . . the 4.6 will get you up to hwy speeds just fine and it does have a nice pull when passing at around 50 or 55 mph. Once you hit 60 or so, it tends to run out of oomph for passing, but it wil still get you up there. For my driving purposes at this time, the 4.6 is all that I require. It still has 230hp and 290 lb ft (90% of it at 2000 rpm) so it is not a weak engine by any means. It does have some grunt, not as much as the 5.4 though. But if you don't require the extra power . . .

My buddy used to sell these trucks and he recommended the 4.6 unless you needed something for heavier towing. His demo was a 5.4 and he said the mileage sucked . . . his experience was it was noticeably worse than the 4.6.

Botomline, both engines are great. 5.4 for extra strength and power just in case you ned it and 4.6 if if your happy with lighter loads and don't care to race the guys at the stoplights . . . if so, I'd buy a Lightning anyway

 

They actually get about the same in the same conditions. Get the 5.4 and I bet you will be glad you did

 

After reading all four pages of this post, I decided to put in my .02 cents. I planned on keeping my truck for years and to continue to modify it. I bought the 4.6L to take advantage of the huge amount of after market parts that I hope will be developed in the years to come for the Mustang crowd. One day we will have heads, cams, stroker kits, etc. at reasonable prices. I think it will be a lot longer wait for these parts if I have the 5.4L. If I were going to buy a truck for only a few years, then I would go for the 5.4L.

 

I was just reading how a number of people believe that there are more problems with 5.4's compared to 4.6's posted on here, I have to imagine if you compare the number of 5.4 engine's built compared to 4.6's that a few opinions would change, remember the superduty's also run 5.4's so there are a lot out there.

The 5.4 does cost more and u can only get an auto in the half ton but on the plus side you also get a bigger diff, besides you never have to wish later that you didn't get a 5.4.

Either way they all have a decent power, if a 4x4 i would never get a 4.2, maybe a 4.6, but when comparing the extra cost for a 5.4 compared to the total cost of the vehicle an extra $1000 or so on $36000 doesnt mean to much

 

I have the 4.6 and just love it!! But, I bought it for a low rider sports truck. It has the 3:08 tall rear-end ratio and 4-speed electronic automatic for excellent gas mileage. I have gotten
over 22 mpg but that was down the freeway 'light-foot'in it,
to see what kind of mileage I can get. I will be putting a new
Innovation Lid on the back and that should help with the mileage
and so should the new K&N and the new non-restrictive exhaust. With an electric fan installed, I'm hoping to eventually get somewhre close to 25 mpg down a big hill. ha

It all depends on what you intend to use the vehicle for. Occasionally I pull a small trailer or a hay wagon down the road a few miles. I'm not trying to drag race pulling a trailer. That's silly. I'm just trying to get from point A to point B without putting a unecessary strain and wear on my truck.

I think, if you intend to pull over 2,000 lbs. on a regular basis, or on long trips, you should step up one level in torque, and get the 5.4. But, if you only pull you family trailer to the lake once a year,
and use the truck as a driver the rest of the year....well, the 4.6 will easily pull the same load as the 5.4 ... just not quite as fast.
Does this sound like sensible advice?

 

I'm just guessing here but my opinion is that there are probably more 4.6's out there than 4.2 and 5.4's combined. The 4.6 has been used for at least 2 or 3 years longer than the 5.4. The 4.6 has been used in an awful lot of police cars since before 95.

 

The 4.6 has been out since 91....

when did the 5.4 come out??

 

97'

 

I read of few post of guys saying they are getting over 20mpg in there 4.6 on the highway I just don't buy it as I have the 4.6 and done many of highway miles when on vacation and the best i ever got was about 19.5 and I use cruise and set it at the limit or a mile or 2 over.

 

actaually there are two differnt 4.6's so the ones in the cop cars and mustangs are romeo , trucks can have either windsor or romeo, windsor have full floating piston pins, the cars do not, except for the 32v 4.6. So if you are comparying windsor 4.6 to windsor 5.4 prob more 5.4