5.4L vs 6.8L in small Class C

Oldme wrote:
Depends on what you want.
No gas RV will be great on MPG.... (if you want better gas mileage, the Chevy seems to be about 1-2 MPG better.)

Compare:

Ford 6.8 V10
2 valve version - old version
265 horsepower at 4,250 rpm
425 foot-pounds at 3,450 rpm

3valve version V10 - new version - only one availabe
Horsepower (SAE net) 362 @ 4750 rpm
Torque 457 lb.-ft. @ 3250 rpm

Ford 5.4 V8
5.4L (330 CID)
Horsepower (SAE net) 255 @ 4500 rpm
Torque 350 lb.-ft. @ 2500 rpm...

It has been reported that the 3 valve V10 is not available in motorhomes. (comment in red added to author's posting)

I recommend that if you go with the V10 in a 24 foot range Class C, you find one built on the E450 Ford chassis instead of the Ford E350 chassis.

The E450 has a different rear differential ratio ("geared lower" with a 4.56:1 ratio) than the E350. You'll find that it will have plenty of pull right off the line and up all grades at speed. The V10 is a high RPM engine (for a truck) and the improved overall ratio of the E450 V10, due to it's rear differential, gets and keeps the engine higher into it's horsepower band for really great performance in a Class C motorhome.

This effect will especially be felt if you get a 2005 or later V10 powered motorhome. From 2005 onward Ford mated their V10 truck engine with their superb 5-speed (6 speeds internally) computer controlled TorqShift transmission. Put this transmission into it's Tow/Haul mode and the V10's performance really shines. Tow/Haul mode is meant to be used in V10 powered trucks when a heavy load is being carried .... and since a motorhome is heavily loading the chassis all the time .... many folks just leave their 2005 and later Class C motorhomes in the Tow/Haul mode all the time. Overdrive still works in Tow/Haul mode (plus you get automatic downhill engine braking), so cruising gas mileage is not effected in this mode while enjoying the improved responsiveness.

Simply my opinion based on having owned both in pickups towing trailers; v10 will be more than up to the task, although thirsty. 5.4 is underpowered for that application. Again, imho.

Where do you plan on taking your motorhome?

I have a smaller lighter 24' and the V10 seems to be sized right. I drive in mountainous terrain.

We put 75,000+ miles in 48 states on a 22 ft. Chevy 3500 chassis with a Chevrolet 350 engine.

We got 11.5 MPG without a towed. 10.5 pulling a Miata.

Tim

V10 doesn't have the bottom-end, off-the-line "grunt" the old Big Blocks like 460 Ford, 454 Chevy, 440 MoPar had. But it's definitely got more than any small block V8 like 351 Ford, 350 Chevy, 360 MoPar. And once it gets moving, it'll outrun any of them. Only one it can't top is the 8.1 Chevy but that engine's discontinued now, and rare in used Class C's.

I'd go for the 6.8L V10 if possible. The MPG difference will be negligible between the two (in fact, on the old Pleasure-Way Excel which had either as an option, there was zero difference in MPG), and the extra two cylinders will help a lot when in the hills.

I don't have any experience with a 5.4L in a class C, but my 1997 24' 9,600# class C averaged a little over 10mpg, over 4 years of driving. I was quite impressed with that.
I believe the newer 2 valve V 10s in class cs are 305HP

Depends on what you want.
No gas RV will be great on MPG.
My 23' with V10 weighs close to 14000 lbs.
Yes 7-8 MPG is good.
The torque ratings make the difference when moving a heavy vehicle.
Torque gets things moving not HP. Usable torque range (RPM) also
helps moving the load.

Compare:

Ford 6.8 V10
2 valve version - old version
265 horsepower at 4,250 rpm
425 foot-pounds at 3,450 rpm

3valve version V10 - new version - only one availabe
Horsepower (SAE net) 362 @ 4750 rpm
Torque 457 lb.-ft. @ 3250 rpm

Ford 5.4 V8
5.4L (330 CID)
Horsepower (SAE net) 255 @ 4500 rpm
Torque 350 lb.-ft. @ 2500 rpm


1978 Chrysler 360 V8- max power they had stock.
360 E58 4-barrel. 220 @ 4,000 280 @ 1,600