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

[BradW]

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

[BradW]

My first post wasn't clear on what truck we have now, its a drw. I went back and added drw to my first post.

[GoPackGo]

OP - It looks like you have a SRW now. What size tires are on it ?

What is the 6th gear ratio in your current manual trans ?

[GoPackGo]

When crunching all these numbers, keep in mind that the DRWs only come with 17 inch wheels but SRWs can have 18 or 20 inch wheels. My point is that at a given speed, the RPMs will be different. And I'm not sure that all the posts on this thread apply to a DRW, which is what you state you will be getting. A couple hundred RPM one way or the other could make a difference to your decision.

Also, you now have a manual trans. You might want to compare the individual ratios, especially for 4th, 5th, and 6th between your manual trans and the auto trans that is offered on the 2018s. Not sure what the ratio is for 5th or 6th in your manual but 5th is 0.85 and 6th is 0.67 in the auto.

[desiphil]

I picked the 3.55 in my 2017 DRW. Mainly because this is my daily driver and wanted as much MPG help as possible. My rig is around 16,000 lbs and this truck pulls it easily. Coming from a 2015 Duramax 3500 with 3.73 SRW, I'm actually shocked how much better it pulls. Completely effortless.

[tinner12002]

BradW wrote:

Travlingman wrote:


4.10 DRW
6th gear 55 = 1624; 60 = 1772; 65 = 1919; 70 = 2067

Thanks for the info. 2067 rpm at 70 sounds pretty reasonable to me. I think I'm turning about 2450 at 70 now with my 6.0 and 6-spd manual.

I don't really know what the impact of tow/haul mode is. Will the tranny still upshift to 6th (I assume is an overdrive gear) while in tow/haul mode?

BradW

Yes it will still upshift, the basic thing T/H mode does is to stretch out the shift points, more RPM between shifts and gives it a firmer shift feel Both of which helps make the tranny live longer.

[tinner12002]

Towing and hauling what your talking about,I would go with the 4.10s hands down! The lower ratio 4.10 will be easier on your equipment.

[tinner12002]

ib516 wrote:

BradW wrote:

ib516 wrote:
Can you get 4.10s in a SRW diesel?

I don't know.

To my knowledge, it's 3.31 and 3.55 only in a SRW diesel.

I think you have to go to a DRW to get 4.10s.

He is getting a DRW, the OP was asking about gear ratio recommendations.

[ACZL]

3.55 SRW, 70 mph = 1750-1800 rpm's. Not too bad, but I personally would rather have 3.73's

[GoPackGo]

" I don't really know what the impact of tow/haul mode is. Will the tranny still upshift to 6th (I assume is an overdrive gear) while in tow/haul mode?

BradW "

Tow/haul mode is a wonderful thing.

Tow/haul mode stretches out the shift points when going up thru the gears, allowing the engine to rev higher before shifting up to the next gear. So it will shift into 6th - just later then if not in tow/haul mode.

Tow/haul also will shift down a gear each time you touch the brakes, assuming the computer knows that downshift will not over-rev the engine. Very nice when you tip over that mountain pass and start down.

FWIW, with my 3.73 gears, I turn about 1650-1700 revs at 60 mph. I usully tow at about 62 with absolutely no problems. Max torque comes in at 1600.

* I get the impression that you're unsure if these trucks can safely tow in 6th gear. They can - easily. Tow/haul does not inhibit that at all. You can run 55 mph in 6th all day with no problem if you want to.

I have noticed an amazing situation many times when hooked up and towing in town. If I am sitting at a red light and take my foot off the brake, the truck and trailer start moving forward - at idle speed. I've even noticed this when I am sitting on a slight upward incline - It starts chugging forward. I am just amazed this is possible.

[shum02]

Travlingman wrote:

shum02 wrote:

GoPackGo wrote:


Are you SURE Ford still doesn't offer 3.73s for duallys ?

Yes, 4:10's are the optional rear end on the DRW F350, standard on the F450.

Go with the 4:10's

DRW drag race

The F-450 comes with 4.30's.

Thanks!

Even better 😉

These engines still love to rev, let them. See how that F350 broke the rear wheels loose twice in that vid 🙂

My 6.0L is around 1800rpm's in 5th at 60mph but I'd much rather have her up at a MIN of 2000 at that same speed. A LOT less carbon on the innards when she is running hot and pretty much the same fuel mileage. Unfortunately I also can't lock out OD.

[Grit_dog]

With 440/910 or whatever the new PStrokes have now, you don't "need" 4.10 gears in the least bit. You may want them to make the truck more of a hot rod, but if you're never going much over 70 you're keeping rpms low anyway.
I'd take low gears if I never drove bobtail at 80-90 mph. 3.55s if I wanted to lower rpms when running empty down the freeway.
My 2c.

[BradW]

Travlingman wrote:


4.10 DRW
6th gear 55 = 1624; 60 = 1772; 65 = 1919; 70 = 2067

Thanks for the info. 2067 rpm at 70 sounds pretty reasonable to me. I think I'm turning about 2450 at 70 now with my 6.0 and 6-spd manual.

I don't really know what the impact of tow/haul mode is. Will the tranny still upshift to 6th (I assume is an overdrive gear) while in tow/haul mode?

BradW

[Travlingman]

shum02 wrote:

GoPackGo wrote:


Are you SURE Ford still doesn't offer 3.73s for duallys ?

Yes, 4:10's are the optional rear end on the DRW F350, standard on the F450.

Go with the 4:10's

DRW drag race

The F-450 comes with 4.30's.

[shum02]

GoPackGo wrote:


Are you SURE Ford still doesn't offer 3.73s for duallys ?

Yes, 4:10's are the optional rear end on the DRW F350, standard on the F450.

Go with the 4:10's

DRW drag race