4.6 vs 5.4
 

Anyone have good opinions on 4.6 vs 5.4, power, fuel economy, reliability?

Economy is the same. If it's different then it's only by 1-2 mpgs which is equal to about 50 bucks a year. Decent power jump in the 5.4. According to most on this site the 5.4 has more reliability issues. I bought the my 5.4 a year ago and no regrets.

I have a 4.6 and it seems very smooth and reliable. I haven't hooked my boat to the truck yet but I have been on a couple road trips with it. It purrs like a kitten and has plenty of power.

There's no replacement for displacement....if you need more power.

If you're looking to tow/haul alot, get the 5.4. If you put a SCREW 5.4 against a SCREW 4.6, the economy would be about dead on because the 4.6 has to work harder than the 5.4. The 4.6 was great in the older (97-03) type because those trucks were alot lighter. Regardless, either engine is strong and stout, especially the 2010 revisions of it. I have 115k on mine. NO CEL's, nothing broken, all routine maintenance.

5.4 for power. 4.6 for reliability (no spark plug issues, cam phaser issues, etc.) It seems like every time I read a thread about a misfire or other electronic issue it's on a 5.4.

06 and up 5.4. Great motor no cam phaser issues. Spark plugs need to be changed every 50k to avoid issues there. Other than that its a solid motor and a much better choice in a 6000lb truck. 4.6 is fine if you haul grocerices but other than that it doesn't have the grunt to get these heavy trucks moving.

I do more than haul groceries with my truck and the 4.6 is fine.

Firewood, loads of dirt, etc, without a hitch.

Before I bought my new truck, I tried out a friends 07 reg. cab 4.6L and the truck I bought, an 08 SCREW w/ a 5.4L towing my 5K camper.

The difference was eye opening in the power of the 5.4 when compared to the 4.6 motor. The power of the4.6L was only marginally better than the 01 F150 SC 4.2L I traded for the 08 5.4L.

The difference in non towing gas mileage is negligible between the 4.6 and 5.4 but the 4.6 used more gas towing the camper because it had to work harder towing that 5K.

Like another poster said, going after groceries is one thing, towing heavy loads is a different animal all together.

HTH,
Bill

Best to drive them both. I wanted an FX4, so my choice was made for me.