Just joined to do some research on the V10's before contemplating ordering a new F450 chassis cab 165" wheel base. The reason I am thinking about the 450 is the additional GVW over the 350. I carry around 2-3 tons of material on a regular bases and would weigh in at about 9600 lbs empty (11' dump body). The 350 would be over the gvw most times and with a 450 would be close to max. All things look fine, except to get a F450 v10 you have to get the 4.88 gears. I see few people have that ratio and little mentioned about them. I am wondering what the fuel mileage might be compared to the 4.30 and what rpms it might be turning at 60 miles an hour. I would be towing at a combined gcw of about 21,000 (trailer and excavator 11,000 lbs) or hauling at about 15,000 gvw. 80% of my driving is either at 21,000 or 15,000 as noted and 80% city driving (very little highway).

 

The F-450 with the 6.4l diesel is available with 4:30 or 4:88 gears. With the V10 I would go with the steepest gears available (4:88 or 5:??)

 

For what it's worth, my Excursion has 4.30s and a 4R100. At 70 mph it turns about 2500 RPM. While that seems a little high, the V10 really doesn't come into its power band until above 3000, so at 2500 on the steep uphills sometimes it feels a little anemic even empty. Off the line, though, the 4.30s give plenty of pep.

If you are doing that much driving with 21,000 or 15,000 GVW, and very little highway, you are probably best off getting the 4.88s, if not a steeper gear. I am not completely certain as to what the transmission and gears are in the current V10 F-series, but with that kind of weight being hauled around definitely go with at least the 4.88s, and expect to be revving the engine quite a bit. I would recommend the diesel except if it's 80% city driving, the gas motor will be better for that, plus the 6.4 seems to be having some growing pains.

As to mileage, expect single digits. Empty on the highway at 70 my Excursion gets about 13-14. On a normal tank I seem to get something around 12.5-13, depending on what I'm doing. The worst I've gotten so far was 10.7, but that was going down the highway at 85-90 on one of those "I don't care how much gas I use I need to get home now" trips. Towing that kind of load in primarily city driving, you will get single digit fuel economy, especially if there is a good sum of idling. As an example, this weekend I installed the front receiver and winch on my truck. I went out to test it to make sure the winch could, in fact, pull the truck up my driveway. In leaving the truck idling for 15 minutes or so while I was doing this maneuver, I watched the lie-o-meter drop from 12.5 down to 12.2, and I reset the thing 600 miles ago.

 

Also forgot to mention, take a look in the 6.4l section at the mpg there getting in F-450s with the diesel. A while back there were guys complaining about getting 7mpg empty with the 6.4l diesel F-450 on the highway. (Most were CC though) I think the V10 could match those mpg #s, for far less $$$ outright as well as cheaper fuel.

 

Yes I have been around the diesel section here, GM, and Dodge and don't like what I see. They all are taking a hit with the fuel mileage and reliability is in the toilet. I would think the light truck diesels of all makes are taking a good percentage of the warranty claims. At present I drive a 2002 GMC Duramax Chassis Cab that I ordered new and I am thinking it is time to replace it. In Canada the big three diesels are around $8000.00-$9200.00 option. For that much money I get to pay more for fuel, higher maintenance cost and a lack of confidence in the long term, especially when the warranty runs out. So after looking around the only option IMO is the v10. GM and Dodge don't really have a motor that I would feel comfortable with, doing the work that I do.

In my Duramax I get between 13-16 miles per imp gallon, depending on what I am doing. I know the V10 won't give me that mileage, "but I don't want to buy a real pig on gas either". In our area there are no v10's around to speak of, and with 4.88's just about none, so I have no one local to ask about these trucks. At the mileage I drive per year I could lose 3-4 miles per gallon and still come out ahead compared to making payments on a diesel motor. Remember with interest it would cost about $10,000 for the option. In four years of payments it would cost about $50.00 per week to own just the diesel motor. The v10/5.4 in Canada is standard n/c in these trucks(although v10's have to be ordered).

You mentioned that you would go with the steepest gears available, in this case that would be 5.38, it ain't gonna happen. I still have a problem with 4.88. I would assume the mileage in the city would probably be comparable as with other ratios due to low speeds and the auto tranny up shifting to keep the rpm's down? My thought is the highway is where I will see a bigger lose? Anyone want to venture what the lose would be in miles per gallon on the highway compaerd to other ratios ? In our area I can just cruise along at 65 and not impede traffic, and that is what I do anyways, loaded or not.

 

hi, i have a 04 f450 4x4 auto cc with a utility box . i also tow amini excavator [about 20k] in a hilly city [almost all city miles ] the lie o meter says 7.1 . i have had it for a year love the truck , a littie under power but, when i think that , i look down & i'm going faster than i sould be . bseg barry

 

Any idea of the axle ratio?

 

Now this is pure opinion, not based on any fact other than my own experience, BUT, I wouldn't be afraid of a V10 w/ 4.88's at all. I have a 2V w/ 4.30's and I'd love to have 4.88's due to my 35" tall tires. It's no slouch w/ the 4.30's by any means, but 4.88's would put it right where I'd like it to be. By the way, I get around 11 w/ 35's, auto and 4.30's.

This thing is a RPM monster. Don't fear the taller gear. With the weight your gonna drag, the 4.88's a minimum IMO. Take it for what its worth.


Dave

 

nobull1,

I would not be able to help you with mpg ,since my F350 has 4.3 rear end . But your thoughts are correct as far as max. trailer weight goes , DRW 350 vs 450.

My Ford trailer Towing Selector (2003 ,page 20 ) tells me :
Regular Chassis , V10 engine ,auto tranny ,4x2

F350 DRW w/4.3 rear max trailer : 13,500 lbs. (GCWR: 20,000 # )

F-450 DRW w/ 4.8 rear max trailer: 16,600 lbs (GCWR:24,000 #)
F-450 DRW w/5.38 rear max trailer :18,600 lbs. (GCWR:26,000 # )

Based on your carry /tow numbers you will be over the factory recommended if you choose a F-350 DRW (w-4.3 rear ) and eventually it will ruin the weakest link (the tranny ) .
Obviously you did your homework by studying the various diesel owners forums and realized that the real life does not match the "diesel vs gas fuel-math " .

May be you can contact some fleet companies that employ V10s to get a better picture .
Good luck.

Ken

 

hi, sorry i have been to riding lessons with the kids , do'nt know axle , but i also have a 250 with 4.30 & the 450 is at least as low . this truck is heavy with tool boxes , hav'nt weighed it but , it was driven here [mo ] from ny. & got 12 mpg the box was put on it drop to 7.5 to 9 . any ??? call 8167975589 barry

 

Here are your RPM calculations at 60mph:

4.30 - 2700
4.88 - 3100
5.38 - 3400

These are, of course, with O/D off or in 5th gear on the 6-speed manual. Pulling those kind of loads, I think the 4.88s are an excellent match, considering you are concerned with some highway use and fuel mileage. Based on my personal experience in a little truck, I think you would get better highway mileage with the 4.88s, but better city mileage with the 5.38s.

Don't fret over the 4.30s, they are not offered with the V-10 for good reason. At the weight you describe, the V-10 would be a dog and would absolutely suck on fuel mileage. That 6.8 loves to hover around 3000 rpm and will serve you well in that capacity.

Just a guesstimate on mpg at the weights you describe:

4.88 - 5 mpg city, 10 mpg highway
5.38 - 6 mpg city, 8-9 mpg highway

I in no way claim to be an expert in your application though... just my best guess based on my own experience.

 

Like I said before, expect single digits for what you're doing. On the highway you may get 10 mpg, but that would be the best that I would expect.

The V10 is a revvy motor. To me, this was a mistake on Ford's part (seeing as it's supposed to be a truck engine), but we have what we have. The thing does love to rev, and revs don't seem to affect its fuel economy significantly. The 4.88s probably ought to do you just fine, but don't expect great mileage. I am surprised to hear you get 13-16 mpg with the Duramax given the amount of city driving you say you do - maybe your "city" driving isn't the same kind most people think of. For example, I get about 12-12.5 mpg on my Excursion with 4.30s on my "city" cycle, which includes a good sum of rural back-roads with stop signs, hills, etc.

I suspect you're going to lose more than 3-4 mpg. The V10 is a pig on fuel, but as you pointed out you're paying less for the motor less for fuel, and less for maintenance. At this point, the V10 is probably goign to be your more durable option, given the fact that the diesels out now are in their infancy and seem to be having problems for the moment. I suspect the 6.4 is going to be very problematic. That said, when I've been around them I've been extremely impressed with how quiet they are and the amount of engineering that went into making them. However neither of those necessarily make them durable.

 

At 415 cubes, it's gonna be. My '01 pulls great from 1000RPMs all the way to 5000. There is a peak in there somewhere, but it's hardly noticable, that's how flat the torque curve is.

No matter what, if the tranny kicks down, the revs go up, but you get the torque multiplication added to it. It revs more than the diesel too, so any impression of "revvy" might be subjective, to say the least.

That's an advantage over the diesel - it has way more revs so can stay in a lower gear than the diesel, and be putting down almost the same, if not more, torque to the ground than the diesel. So, yeah, it's "revvy"

--

To the original poster:

Gearing is a funny thing. For city driving, you will want to go as low as you can for gearing, in my opinion. Sure, there's a break-even point, but overall, the more gear you have, the less strain on the drivetrain, the less throttle needed for any given circumstance, and just overall easier for the truck to pull that load.

Plus, you get more engine braking, which means your brakes will last longer (maybe not enough to notice).

With the lower gearing, you don't need as much throttle to move the load, so, theoretically, MPGs will improve.

I think what I mean is that you should go for the lowest gearing possible in that chassis if you're going to be driving 80% stop-and-go especially near- or at-max load. Not entirely for MPGs, but defnitely for driveability and wear-and-tear on the drivetrain.

On the highway, there is a break-even point where the MPGs and the throttle position and the RPMs all meet up. Below and above that point, MPGs suffer. With more gearing comes less throttle, but more RPMs. With less gearing, more throttle, less RPMs. Where the break-even point is, I don't know. But it does exist. For instance, my '96 t-bird 4.6L that got 23-24MPGs on the highway with 3.27's, suddenly went to 26-27MPGs on the highway with 3.73's, even though the RPMs went up. All at 70MPH, hand-calculated, GPS checked. And, stop-and-go mileage went up about 20% unless I used all that extra power from the gears.

The Ford modulars don't seem to be effected by higher RPMs when the load decreases accordingly. Within reason of course, there are exceptions - plenty of them ...

 

hi, something to remember is the 450 has 19.5 tires , which will raise the 4.88 gears some . my buddy has a 550 with a 6.0 says he get around 10 mpgs . how many hwy miles do you run , the deisel advantage gets bigger the more hwy miles you do. i only put on about 12-14 k ,mosty in town. also if your talking a new truck you get the 3v motor& 5 speed auto [362 hp] mine has the 2v [310]& 4speed auto. barry

 

My RPM calculations included the 19.5 inch tire size.