2018 SuperDuty DRW - 3.55 or 4.10 Gears?

[BradW]

We are close to ordering the following:
2018 XLT DRW F-350 SuperDuty Powerstroke, 4-door, 4X4

It will seldom be driven empty. It will primarily be used to haul a 4,000 lb truck camper while towing a 7,000 lb jeep/carhauler. Total weight of truck camper and jeep/carhauler will be right at 18,000 lbs. Quite a bit of our towing will be in the mtns.

Our current truck is a 2006 F-350 DRW PS 6-spd manual with 4.10 gears. I luv the 4.10 gears on that truck with the manual tranny. But I'm afraid 4.10 gears will be too low on the 2018 with an automatic, but they don't offer 3.73 gears and 3.55 seem too high for 18,000 lbs. I've never owned a tow rig with an automatic tranny, so I have zero experience in that area.

It appears that Ford only offers 3.55 or 4.10 gears in 2018 truck we want. Anyone have any suggestions on which gear ratio? I'm not tremendously concerned with fuel mileage because we will likely be driving the truck less than 6,000 miles per year. Probably will not be exceeding 68 mph while interstate driving.

Thanks for any help,
BradW

[shum02]

4x4ord wrote:

shum02 wrote:

Westcoasting wrote:

BradW wrote:

Travlingman wrote:

4.10 DRW
6th gear: 70 = 2067

Finally got hold of a friend of mine who has a 2017 DRW F350 PSD. I thought he had the 3.55 gears, but it turns out he has 4.10 gears. He confirmed about 2050-2100 rpm at 70. I can live with that. So I will be ordering the truck with 4.10 gears.

Thanks all who submitted info on this thread, I'm sure there will be many people benefit from the info.

BradW

That is a great choice! I'm surprised by all the responses that say otherwise. I work in the oil patch in Alberta and our company has all Ford Trucks, the dually 4:10 is the best for any amount of towing 🙂

I have to agree. These are V8 diesel's that can and do love to rev. Don't think that down at 1700rpm's the engines are making enough heat to stay healthy but up at around 2k that should be the sweet spot for towing/hauling to keep them clean.

It's my thought having owned a 6.0L for a while that if Ford had put a minimum of 4:10's in all the trucks they'd have cut the problems of this motor in half. It loves to be hot and loves to rev - fuel mileage be damned! Add that along with frequent oil changes and issues diminish. JMHO.

Think about what your saying. An engine needs an amount of fuel to do the work required of it. At higher rpm it is a little less efficient but it is basically going to need the same amount of fuel as if it were pulling that load at a little lower rpm. However, there is a good chance the slower turning engine will be pumping less air than the higher revving engine.....less air for the same amount of fuel means more heat not less.

Running in 5th(OD) my truck struggles to keep the coolant up around 195 and the oil about in the same spot. I run the truck constantly with the T/H on to keep the truck in gears longer and delay the use of OD, if I could lock it out like the new trucks I would. The faster you drive the truck or more you drive it with a load the more easily she stays at her operating temp of 195F. This keeps the EGR and intake clean of carbon build up. Regular oil and coolant changes speak for themselves especially in this engine.

Much reading about this truck over the last 8 years and doing all the work on it myself says this has merit. Truck that are lugged around in order to get the best fuel mileage possible out of an 8000lb beast are the one who seem to have the most issue. Those beating on their trucks in stock form, pulling within their #'s and doing the required maintenance seem to have the least issues and that includes lifting the heads.

I have almost 300k miles on my truck and yes it has had a few issues, what pickup wouldn't but none that have been terminal to the engine.

Diesel's love to be hot, much more so than gassers, they also don't wet stack

[BradW]

shum02 wrote:
These are V8 diesel's that can and do love to rev. Don't think that down at 1700rpm's the engines are making enough heat to stay healthy but up at around 2k that should be the sweet spot for towing/hauling to keep them clean.

It's my thought having owned a 6.0L for a while that if Ford had put a minimum of 4:10's in all the trucks they'd have cut the problems of this motor in half. It loves to be hot and loves to rev - fuel mileage be damned! Add that along with frequent oil changes and issues diminish. JMHO.

We bought our 2006 6.0 PSD new, so we have had it almost 12 years. It has never been in the shop. A couple of things I was told early on and still follow to this day:
1) don't start it and then turn it off before it warms up
2) don't let it idle for a long time in cold weather
3) don't lug the motor; drive like a 4 cyl Yoter, which I have lots of experience with 🙂
4) keep the motor oil clean and filters changed
5) keep the fuel filters changed
6) use the Ford fuel additive (PM22 or something like that)
7) change and flush the coolant regularly
😎 put a coolant filter in it
9) don't put a power chip in it

BradW

[Cummins12V98]

With the RAM/Cummins the 3.42's will get better mileage solo ALL day long compared to the 4.10's. Towing they will get the same mileage in 5th as the 4.10's in 6th. Both will be turning around 1,750rpm's.

I am sure this would be true with the Ford.

[4x4ord]

shum02 wrote:

Westcoasting wrote:

BradW wrote:

Travlingman wrote:

4.10 DRW
6th gear: 70 = 2067

Finally got hold of a friend of mine who has a 2017 DRW F350 PSD. I thought he had the 3.55 gears, but it turns out he has 4.10 gears. He confirmed about 2050-2100 rpm at 70. I can live with that. So I will be ordering the truck with 4.10 gears.

Thanks all who submitted info on this thread, I'm sure there will be many people benefit from the info.

BradW

That is a great choice! I'm surprised by all the responses that say otherwise. I work in the oil patch in Alberta and our company has all Ford Trucks, the dually 4:10 is the best for any amount of towing 🙂

I have to agree. These are V8 diesel's that can and do love to rev. Don't think that down at 1700rpm's the engines are making enough heat to stay healthy but up at around 2k that should be the sweet spot for towing/hauling to keep them clean.

It's my thought having owned a 6.0L for a while that if Ford had put a minimum of 4:10's in all the trucks they'd have cut the problems of this motor in half. It loves to be hot and loves to rev - fuel mileage be damned! Add that along with frequent oil changes and issues diminish. JMHO.

Think about what your saying. An engine needs an amount of fuel to do the work required of it. At higher rpm it is a little less efficient but it is basically going to need the same amount of fuel as if it were pulling that load at a little lower rpm. However, there is a good chance the slower turning engine will be pumping less air than the higher revving engine.....less air for the same amount of fuel means more heat not less.

[4x4ord]

1stgenfarmboy wrote:
Out of all the diesel HD trucks I have owned the 2 with 4:10's got better MPG than the 3 with 3:54's, now if you were in the habbit of running 80+mph that would probably change.

I wonder why.....My guess is the axle ratio is not the reason. The brake specific fuel consumption of a diesel engine is always better at lower rpms.

[Grit_dog]

1stgenfarmboy wrote:
Out of all the diesel HD trucks I have owned the 2 with 4:10's got better MPG than the 3 with 3:54's, now if you were in the habbit of running 80+mph that would probably change.

That’s IL talking vs most places west of the Mississippi where 80mph plus is the norm in some states. Good point though. Lower speeds, lower gears will be more efficient because the trans has the ratios to handle the engine the same but the wheels are easier to turn.

[Grit_dog]

shum02 wrote:

Westcoasting wrote:

BradW wrote:

Travlingman wrote:

4.10 DRW
6th gear: 70 = 2067

Finally got hold of a friend of mine who has a 2017 DRW F350 PSD. I thought he had the 3.55 gears, but it turns out he has 4.10 gears. He confirmed about 2050-2100 rpm at 70. I can live with that. So I will be ordering the truck with 4.10 gears.

Thanks all who submitted info on this thread, I'm sure there will be many people benefit from the info.

BradW

That is a great choice! I'm surprised by all the responses that say otherwise. I work in the oil patch in Alberta and our company has all Ford Trucks, the dually 4:10 is the best for any amount of towing 🙂

I have to agree. These are V8 diesel's that can and do love to rev. Don't think that down at 1700rpm's the engines are making enough heat to stay healthy but up at around 2k that should be the sweet spot for towing/hauling to keep them clean.

It's my thought having owned a 6.0L for a while that if Ford had put a minimum of 4:10's in all the trucks they'd have cut the problems of this motor in half. It loves to be hot and loves to rev - fuel mileage be damned! Add that along with frequent oil changes and issues diminish. JMHO.

WOW, why didn’t anyone else think of that? You think running higher rpms would alleviate the stretched head bolts on piles of junk 6.0s? It wouldn’t.
But , in general, I agree with you. Run diesels hard and hot. THats what they’re designed for.

[1stgenfarmboy]

Out of all the diesel HD trucks I have owned the 2 with 4:10's got better MPG than the 3 with 3:54's, now if you were in the habbit of running 80+mph that would probably change.

[tinner12002]

I was thinking, but I will check to make sure, I'm thinking my RPM at 70mph is still under 1900rpm with truck in my sig. Not sure why the Ford rpm is so much higher.

[shum02]

Westcoasting wrote:

BradW wrote:

Travlingman wrote:

4.10 DRW
6th gear: 70 = 2067

Finally got hold of a friend of mine who has a 2017 DRW F350 PSD. I thought he had the 3.55 gears, but it turns out he has 4.10 gears. He confirmed about 2050-2100 rpm at 70. I can live with that. So I will be ordering the truck with 4.10 gears.

Thanks all who submitted info on this thread, I'm sure there will be many people benefit from the info.

BradW

That is a great choice! I'm surprised by all the responses that say otherwise. I work in the oil patch in Alberta and our company has all Ford Trucks, the dually 4:10 is the best for any amount of towing 🙂

I have to agree. These are V8 diesel's that can and do love to rev. Don't think that down at 1700rpm's the engines are making enough heat to stay healthy but up at around 2k that should be the sweet spot for towing/hauling to keep them clean.

It's my thought having owned a 6.0L for a while that if Ford had put a minimum of 4:10's in all the trucks they'd have cut the problems of this motor in half. It loves to be hot and loves to rev - fuel mileage be damned! Add that along with frequent oil changes and issues diminish. JMHO.

[Westcoasting]

BradW wrote:

Travlingman wrote:

4.10 DRW
6th gear: 70 = 2067

Finally got hold of a friend of mine who has a 2017 DRW F350 PSD. I thought he had the 3.55 gears, but it turns out he has 4.10 gears. He confirmed about 2050-2100 rpm at 70. I can live with that. So I will be ordering the truck with 4.10 gears.

Thanks all who submitted info on this thread, I'm sure there will be many people benefit from the info.

BradW

That is a great choice! I'm surprised by all the responses that say otherwise. I work in the oil patch in Alberta and our company has all Ford Trucks, the dually 4:10 is the best for any amount of towing 🙂

[GoPackGo]

4X4ord - What an excellent post !

[BradW]

a

[4x4ord]

BradW wrote:

Travlingman wrote:

4.10 DRW
6th gear: 70 = 2067

Finally got hold of a friend of mine who has a 2017 DRW F350 PSD. I thought he had the 3.55 gears, but it turns out he has 4.10 gears. He confirmed about 2050-2100 rpm at 70. I can live with that. So I will be ordering the truck with 4.10 gears.

Thanks all who submitted info on this thread, I'm sure there will be many people benefit from the info.

BradW

It might be too late for me to change your mind but I think going with 4.10s is a mistake. First of all there is absolutely no comparison whatsoever between the 6.0 and a new 6.7 Powerstroke. The 2017 Powerstrke is capable of making 304 HP at 1700 rpm. When cruising down the highway with a large 5th wheel in tow at 70 mph you might be needing 140 hp... The whole idea of overdrive gears is to slow the engine down when power isn't required.

Secondly you are taking advice from people on forums who base their opinions on their experience. I have no doubt that someone with a 2017 f350 dually would be happy with his 4.10 gears but that certainly doesn't mean he wouldn't be happy with 3.55 gears. Has he tried 3.55 gears. Engineers know what they are doing....it is very simple math for them to recommend the best gear ratio for various applications. The Ford engineers recommend 3.55 gears for an application like yours because it is the best choice. 4.10s will work, 3.55 will work better.



Edit: I was making the point that there is a huge difference between the 2006 6.0 to a 2018 6.7 Powerstroke. I mentioned that the 6.7 can produce 304 HP at 1700 rpm.....I should have also mention that the 6.0 was capable of around 160 HP at 1700 rpm. The 6.0 didn't reach peak torque until 2000 rpm.