5.4L V8 vs 6.8L V10 3 valve vs 2 valve
 

So I'm looking to getting a different truck. Right now I'm using a 1999 F150 XLT 4x4 extended cab long bed 5.4L V8 automatic 3.55 9.75" just rolled 242,000 earlier this week. What I can say about the engine is that its nearly a gutless pig. I mean I've gotten 19.2 hand calculated mpg with a bit of load maybe 600lbs at most with 2 passengers. However when towing my dad's boat with it it doesn't feel like it has any power what so ever. Truck on the scale unloaded is right around 6,500lbs. Boat itself with a trailer is right around 1,600lbs loaded.

I'm looking to upgrade to a F250 Super duty crew cab short bed with a V10 or V8. However I would like to know is how shoehorned is the engine under the hood compared to the same truck with a 5.4L. My F150 is difficult to work on for getting plugs out especially the number 7 and 8 because they are under the cowl. When we first had the truck we took it to a shop to have them do the plugs...the (explicit) kid that did it ended up tearing the boot on the number 8 coil pack and a few days later the plug backed out of the head. Threads were fine but they never used anti-seize on it. We ended up doing the plugs ourselves after that fiasco.

For the truck I am looking into the 3 valve. One of my questions is how much power did the 3 valve engine make over the 2 valve...I'm not talking what the spec sheet says, I'm talking driving down the road is it significantly more or is it about the same? How much harder is it to do the plugs on the V10 over the V8? I've thought that adding a 1" body lift could possibly help with the clearance on doing the plugs in the back.

I do every bit of work I can on my truck and rather not take it in to a shop or Ford Dealer to do the work.

1) If your 5.4 is a gutless pig you need to fix it. They are not gutless. If you are expecting a race truck then you will be underwhelmed by a 5.4 or a 6.8 in a SuperDuty. They are designed to pull in their TQ range which they do very well.
2) You will notice a difference between the 2 valve and the 3 valve in the seat of your pants... but... not earth shatteringly different.
3) Changing plugs on a 6.8 is about a half hour job compared to a F150. MUCH MUCH easier to do plugs on a superduty.

Enjoy the hunt.

Thanks!

Jeremiah

Do you still have to pop the fuel rail off to get each coil pack off or did they redesign that from previous generations? But when I did my F150 plugs it took about 2 hours to do them all. How much more room does the super duty have to do this with the V10?

Hmm, I didn't have to pop the fuel rails off my V10 or my 5.4 (that one was in my 97 F150.) Just undo the bolt pull out coil. No biggie at all.

The room difference is significant between the F150 and the Super Duty.

Like with my 5.4 I could get to the front four plugs relatively easily (two on each bank) the back four had to basically be done by feel (not real fun)

On the V10, I remove the air cleaner assembly, the DPEF bracket, and then I have all 10 of the coils in view.. wide open.

The only minor issue with the V10 is the rear most coil on the drivers side. Its behind the EGR if you have an EGR. Its still not hard at all.

Literally a 40 minute job after you do it a time or two. The hardest part of it all is keeping your footing, even on my 2wd (plus I am short) I had to stand on the bumper to do the work.

Both my 5.4 and my 6.8 were 2 valve versions.

Thanks!

Jeremiah

I am wondering the same thing. Im looking for a ext cab sb. I drove a 2009 5.4 sc lb at work with a about 2000 lbs of tools and equipment in the back. I was not pleased with how much I had to push on the pedel to accelerate. That's why im curious about a v10, how much more power does it really have under a load. Im looking for a daily driver, that does towing about once a month. Very interested in what is said here.

Did you ever have the spark plugs backing out of the heads on your trucks?

I'm mostly interested in the V10 for plowing snow in the winter. How's the oil filter situated? On my 5.4L its sideways behind the driver's tire.

I've ridden in an 04 F250 with the 5.4L and it seemed to be okay but when your trying to get up to freeway speeds it doesn't quite have enough power.

One other thing how is the 5R110 vs the 4R100 transmissions pair up? It sounds as though a lot of people prefer the 5R110 over the 4R100 no one has really said why though.

My buddy and I have "identicle" trucks, his a 06 mine an 02. Mine has the 5.4/4r100/4.10s his had the 5.4/5r110/3.73. Mine with the 4.10s is the same off the line as his, but you can tell the 3v had more power mainly in the upper rpms, which comes into play as ford added 35hp to the 3v motor.

As far as functionality or two trucks are a wash. His can turn better but you get used to your turning radius. Coils did not offer any ride improvement at all.

If your main concern is speed get a 3v f150 lighter truck with more powerful engine. V10 had more torque down low and will have more grunt but nothing measurably higher up to without help from a tuner which imo is only good an the 3v motors

If your having trouble getting up to freeway speed then there's something amiss. Either incorrectly geared or a motor issue.

5r110 is much more desired over it's predecessor because it's a 5 speed with internal thermostat, external spin off filter, has a tow haul mode that changes shift strategies and is generally considered to be much stronger overall then the 4r100 stock for stock

Can't exactly put a 8 1/2' plow on an F150 without tiring the suspension after a while. Plus my current truck is a bit too small. Needing a crew cab short bed. Truck is going to be the more or less so the family ride for trips... Kind of hard to get a toddler's seat in the back seat or getting a tall person to be comfortable is something that can't be done in an extended cab. I do like that the 5R110 does have the option in real cold weather to use its "hidden" gear til it warms up. Least that's how people explained it to me.

Just a real dumb question but is there really any mileage gains with a 3 valve or not really?

I know the truck is in stock configuration in gearing. Last I knew (about 3 years now) it had 3.73. Truck is a extended cab long bed F250 super duty. IIRC its a 2001 or 2002 auto. It didn't seem like it had any power to it.

Way I see it the 5.4l and the 6.8l will give the same mileage or within a 1 or 2 mpgs of each other in that large of a truck.

Or a driver that doesn't know how to use the skinny pedal. It goes all the way to the floor for a reason.

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I had the throttle three quarters of the way down and it still felt sluggish. It had no signs of a mis-fire and there was no weight except for 3 passengers.

3.73 on a 2v 5.4 is not a great combo. 4.10s give it enough grunt. 4.30s would be the ideal combo. But with that being said. Its a gas motor use the skinny pedal and she'll move.

5.4 will average 10-14. 6.8 will average 9-12

Did anything get changed up on the engines when they went to 3 valve setup? Meaning was other stuff put on there to make it more crowded or was it all nearly the same?