V10 with heavy camper, 4.10, 4.30, 4.88 gears??

[Solo2puller]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lightningfast01</div><div class="ubbcode-body">He hauled a Mustang to Houston on an open trailer and got 7.5mpg at 70mph. </div></div> I've never got less than 11.5 towing that same load, same route. Usually get well over 12. Been doing it for years. Not sure what you're doing to get such crummy mileage. Mine's a 2v motor in a 2WD truck. That's some of the difference. The last car I hauled weighed a little less than a Mustang, but my experience says the weight is much less of a factor than the shape, especially where it's flat. It gets about the same empty for me, but that's because of the type of driving I do - all city these days. Get it on the highway and it will get much better than 14, and as high as mid 15's if you can keep your foot out of it. I've got a complete fuel log since it was new, so these are actual numbers - not from the display.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> I did the math on driving 40K per year. Even with diesel being 50 cents more a gallon than gasoline. It still cost 2 grand a year more in gasoline. That was assuming a 3-5mpg inefficiency in gas. </div></div> So that's a $0.05/mile difference. (2000 miles/40K/year) That's quite a bit.

Funny thing about the per mile cost calculation - the outcome makes a big difference where you start the mpg numbers and the fuel prices. A 3 mpg difference with the V10 at 9 and the PSD at 12 with fuel at $2.79 and $3.29 shows a per mile difference of $0.036 per mile. Move the mpg up the scale a little to something more realistic, say 11 and 14, and you get $0.018 per mile, same fuel prices. Those numbers drastically change your $2K/year difference in fuel spending. At $0.36/mi it's $1433 and at $0.018/mi it only $745. This is all with the same fuel prices of $2.79 and $3.29. Move the fuel prices and keep the mpg the same and you get similar (if not as drastic) results.

When fuel prices were lower (both types) it made an even bigger impact because the difference in cost between the 2 fuels was a much larger percentage of the total cost. As fuel prices have crept up the difference betweent the 2 has narrowed.

Not throwing stones, just making sure folks understand how it works. There's a lot of numbers tossed around and most folks don't take the time to really understand them.

40K/year is a lot of miles. With that kind of seat time I'd be looking at PSD pretty seriously. I just turned 61K on mine and it's an '03!

[Smokewagun]

Solo, very interesting post on numbers. I am considering dropping down to an F-150 again because a diesel even at my 50k+ miles a year driving isn't making much sense. I look at the whole, not the cost per mile. My boss rather see the yearly hit instead of the weekly/monthly. I am thinking the F-150 will ultimately be cheaper for a butt carrier and only 5k miles a year (best) towing my 6,000# travel trailer. I'd like to consider the V-10 as the fuel consumption cost isn't far off the current 2008 figures I am seeing and the Superduty with the V-10 is only about $3500 more than a comparable F-150. Unfortunately, I trade each year, and none of our local dealers will even look at a V-10 trade for their lots without the owner of the V-10 taking it in the keister for what they think will become "lot rot". Opinions anyone? I'd love to hear them.

Oh, on edit, as you can see in my sig, I have dabbled with F-150's in between recent F-250's,a nd I log every tank fill on each truck. To date, I have never seen the real cost savings in 9 years of a diesel over gas (fuel costs). At best, I have seen the costs per year (45,000 miles minimum) around $250 between the two (gas/diesel). The diesle trucks used to command better resale in my area, but that is slowly dropping off, too.

[Solo2puller]

You need a 4 cylinder Ranger, or better yet a Focus. Keep an old truck for the couple of times a year you tow. I know that's not what you're after, but it would make the most sense money-wise. [img]/forums/images/%%GRAEMLIN_URL%%/smile.gif[/img] Even better - at 50K/year you should be riding a 50cc scooter. 80mpg, $2-3K out the door.

All kidding aside...

I'd forget about trading if your dealer won't talk on a V10 after a year. There are plenty of folks who want one, and with today's availability of information there are folks all over the country shopping - all over the country. You don't need to be restricted to your local geography when you sell. I'm constantly looking for stuff all over the place.

If you go that route, keep up your fuel and maintenance logs. They're worth something when you're selling privately, while the dealer could care less. Remember that selling privately you'll have to get what the dealer will give you on trade plus the difference in sales tax. Your trade offsets the sales price on a new one, so to break even selling yourself you'll have to get his price plus (insert your sales tax rate here). Dealers use that as a scare tactic all the time to get you to trade because it sounds like it would be hard to do, but believe me it's not. If you ever want to find out what you're really getting for your trade just do an X or A plan deal without a trade, then add in your trade when you're about to close the deal. You'll be surprised how low that trade has become all of a sudden.

It's funny - I see a lot more V10's now than I used to. Maybe it's just here, but I'd love to see the sales numbers by year for the last several years. I don't think you'd have a hard time selling it at all.

[bigjimcruising]

All good points and useful info! Here is what I'm thinking for expenses over a year period.

Diesel:
15000 miles per year, 8 mpg
$3.55 per gallon
2 oil changes at $95 each
1 fuel filter change at $180
Cost to operate for the year: $7026.25

Gas:
15000 miles per year, 8 mpg
$3.15 per gallon
2 oil changes at $50 each
Don't know about fuel filters?
Cost to operate for the year: $6006.25

Savings for the year: $1020. I used average prices around my area and dealer prices for service. I can do even better on the gas by shopping around, not much better on diesel. I don't know yet if my payments will be lower but I would think they should be since the gas engine costs less then the diesel engine. I'll see what my dealer can do for me in a trade. Even if the payments stay the same it would seem I would save a nice bit of money each year. And if I can get a little better mileage out of the gas then it seems I way ahead!

Thanks for the thoughts and input everyone! This is helping me a lot! So far I'm still leaning towards the 4.30 gears just because of the weight of my camper. I'm a lot more comfortable with running a gas engine at 3200 rpm's up a long hill then I am running a diesel that high! Plus the cost seems to be much better with gas engine.

[DirtFarmer]

Good luck with your new truck. Sounds like you've picked out a good setup. Truck campers are sure squirrely when it comes to fuel mileage. With their (relatively) low weight but horrible frontal profile, I've had them return close to empty-weight mpg when loafing along at low speeds but return horrendous mpg at higher speeds and into head winds. I grow weary of the wind noise and clumsy handling of truck campers, but on the bright side, having the cab always in the shade is nice during the summer!

[Lightningfast01]

Yeah low mileage doesn't pay to drive a diesel. I run 40-50K a year chasing the racing circuits with my enclosed trailer and gear 12K or so. The parking lot is full of tow rigs of all kinds. We all talk and compare what our rigs require. All of the V10 guys hauling their race cars cry about 6-8 mpg. All of the diesel guys get about 11-13 which is a very significant savings even with gas being cheaper. When gas was the same or more a diesel saved hand over fist. The Cummins and Duracrud guys claim to get 15-17mpg hauling. If I went back to a half ton it would be a GM they have the fuel management on that 5.3 getting 17-20mpg. F150's suck fuel. One of the racers had a problematic 6L and traded it for a V10. So he has first hand experience of the two power plants hauling the same trailer to the same places. He got 4mpg less than his 6L but they were trouble free with the V10 so it was worth it to him.
I also agree in the past you have not been able to give away a V10 anything. I hope that changes with the poor 6.4L mileage. Part of buying my PSD was knowing I would have resale value at 100K plus when people were giving away V10's if they could. Plus I like the way it pulls without having to rev it up. I will go drive a new V10 sometime just to see what they are like. I sure like being able to dial in 30 lbs of boost when needed.

[bigjimcruising]

Wow! Lots of great info from everyone! This is helping me a lot!

I have thought of another follow up question for everyone. I'll ask it here and then see if it needs a new post.

For those of you with the V10 engines: could you post what your gear ratio's are and what your rpm's at 65 mph on level ground are? This would be a great way to see just where the engines are running with the different gear sets.

Thanks everyone for your input and ideas!!

[DirtFarmer]

Hey Jim-

Here's some numbers from an RPM calculator for 60mph in straight gear and OD assuming 235/85R16 tires and 15% reduction for OD for three common gear ratios. If you have other tire sizes, etc you'd like me to try, let me know.

3.73:1: width = 235.0, ratio = 85.0, rim = 16.0, dia = 31.7
rear gear = 3.73, 60mph rpm = 2371, 60mph rpmOD = 1802

4.10:1: width = 235.0, ratio = 85.0, rim = 16.0, dia = 31.7
rear gear = 4.10, 60mph rpm = 2606, 60mph rpmOD = 1981

4.30:1: width = 235.0, ratio = 85.0, rim = 16.0, dia = 31.7
rear gear = 4.30, 60mph rpm = 2733, 60mph rpmOD = 2077

[bigjimcruising]

Thanks for that work DirtFarmer! Great calculator! I was surprised to see such a small difference from the 3.73's to the 4.30's. Could you do the same with 4.56 and 4.88 gears? I got a quote from my ford dealer today with 4.88 gears but that sounds pretty high for only hauling around my camper. I don't do any towing even though I'm set up for it. Might tow around a small toy trailer in the future but it won't be much so the 4.88's sound like overkill. Thanks, Jim.

[DirtFarmer]

Here ya go!

3.73:1: width = 235.0, ratio = 85.0, rim = 16.0, dia = 31.7
rear gear = 3.73, 60mph rpm = 2371, 60mph rpmOD = 1802

4.10:1: width = 235.0, ratio = 85.0, rim = 16.0, dia = 31.7
rear gear = 4.10, 60mph rpm = 2606, 60mph rpmOD = 1981

4.30:1: width = 235.0, ratio = 85.0, rim = 16.0, dia = 31.7
rear gear = 4.30, 60mph rpm = 2733, 60mph rpmOD = 2077

4.56:1: width = 235.0, ratio = 85.0, rim = 16.0, dia = 31.7
rear gear = 4.56, 60mph rpm = 2899, 60mph rpmOD = 2203

4.88:1: width = 235.0, ratio = 85.0, rim = 16.0, dia = 31.7
rear gear = 4.88, 60mph rpm = 3102, 60mph rpmOD = 2357

[bigjimcruising]

Thanks a bunch! It looks like the 4.88 rpm's matches the rpm's that my diesel runs. Very interesting. So the transmission gears must be pretty close or the same between the diesel and gas engines. Very surprising results to me. And only about 550 rpm's difference from the 3.73's and the 4.88's. I was expecting a greater difference. Very interesting!

Thanks a whole lot DirtFarmer! That was a real eye opener for me! By the way, really liked your flatbed! Wish I could build stuff like that!

[DirtFarmer]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bigjimcruising</div><div class="ubbcode-body">It looks like the 4.88 rpm's matches the rpm's that my diesel runs. Very interesting. So the transmission gears must be pretty close or the same between the diesel and gas engines. </div></div>

Hey Jim-

I stumbled across this in the general diesel section:

Gas version (wide ratio)

1st 5.72:1
2nd 2.94:1
3rd 1.61:1
4th 1.00:1
5th 0.76:1

Diesel version (close ratio)

1st 4.14:1
2nd 2.37:1
3rd 1.42:1
4th 1.00:1
5th 0.76:1

This was for the older ZF5 five speed stick that went in both the diesel and gas rigs. The lower gears were different, but straight gear and OD were the same for gas and diesel. If this holds for other trannies, then your observation that the top two gears are generally the same for either engine is spot on.

Mark

[bigjimcruising]

So it looks like the auto trans for both engines must be pretty close, at least in the top gears. I'm just surprised that the difference from the high to low gears was so small. I guess my next step is to try and find the power curves for the gas engine and see where they cross. That should give me a better idea of which gears I should get. Sure wish I had known you before I bought my truck! lol! Thanks for all your help Mark!! Jim.

[dssamp]

I have an 01 7.3 with 3.73 gearing..lance camper 11.5 foot with all the goodies. Sticker on the camper says 3300lbs with propane & water. Probably 4k when my wife loads it. Been across country several times. Running 70-75mph averages 11-12mpg. Running 55 I get about 13mpg. Not a lot of difference when I hook up the boat. Only changes I made are the intake and exhaust...no programmer.
Empty around town I get right at 15mpg. I think the 4.88 gears a killing you, and not needed. I live in Colorado and do a lot of hunting, fishing trips in the mountains. Only time it slows down is if I'm pulling a pass with a really hard headwind...but even then I've never found a pass where I can't maintain the posted speed limit....might be 2nd gear but the thing pulls.

If you are trading I'd find a 7.3 or good 6.0 with better gears. I think the V10 will put you in the 6-10 mpg range against headwinds or hills. Just my 2c's worth.

[ddg00001]

Just my two cents, but it seems that its definitely the 4:88 thats causing you the problems. Its great to have the 4:88 when your towing 25000 pounds. It will get that load moving quick. Any other time its just too much. If your not doing any heavy towing, change to a 4:30 or 4:10 and the fuel mileage should improve dramatically. The sweet spot in my 06 350 6.0 dually w/4:10 is just under 2000 rpm. I get around 16 empty on the highway.