Tow haul question

[Flashman]

My last 2 diesels were equipped with a manual tranny - best thing for mountain towing.

Now in my new 3500 it has the Aisin tranny with a 342 rear end. I will be towing a tow hauler TT of about 11,000 lbs. In the mountains I see the need for Tow haul but how about the in the flats? Seems like MPG would suffer in Tow haul.

[transamz9]

Flashman wrote:
How tall are the tires - I think the stock 275/70/18s are puny looking.

Mine are 285/60/20s. The are a touch wider but are the same height.

[Flashman]

How tall are the tires - I think the stock 275/70/18s are puny looking.

[transamz9]

Flashman wrote:

transamz9 wrote:

Flashman wrote:

Lynnmor wrote:
Whatever floats you boat, but asking a transmission to operate at 1200 RPM while towing a load is what the engineers consider abuse and installed tow/haul mode for those that care.

Maybe I should have stayed with a manual tranny. They don't care what rpm the engine is running.

Neither does the auto really. I have the same running gear as you and I see zero difference in fuel mileage between 5th and 6th towing. I toe 20k with mine.

Ah Hah! A self confessed weight criminal. If you have the 342 rear end you are only supposed to Tow 18,000 lbs. (I think)

The Shame.

Actually according to Ram is like 16,XXX but who's counting. Also 99% of the time it's pulling closer to 21K I was just rounding off.
I tow a heavy boat behind my 5th wheel.

With the Aisin and 3.42's on tall rubber 65 mph is the magic number with TH turned on. When running on highway with rolling terrain I lock it in 5th unless I'm running traffic running 70+. 55 is the number between 4th and 5th. It likes to shift @ 2k.

[Flashman]

transamz9 wrote:

Flashman wrote:

Lynnmor wrote:
Whatever floats you boat, but asking a transmission to operate at 1200 RPM while towing a load is what the engineers consider abuse and installed tow/haul mode for those that care.

Maybe I should have stayed with a manual tranny. They don't care what rpm the engine is running.

Neither does the auto really. I have the same running gear as you and I see zero difference in fuel mileage between 5th and 6th towing. I toe 20k with mine.

Ah Hah! A self confessed weight criminal. If you have the 342 rear end you are only supposed to Tow 18,000 lbs. (I think)

The Shame.

[Flashman]

Bobbo wrote:

Flashman wrote:

Lynnmor wrote:
Whatever floats you boat, but asking a transmission to operate at 1200 RPM while towing a load is what the engineers consider abuse and installed tow/haul mode for those that care.

Maybe I should have stayed with a manual tranny. They don't care what rpm the engine is running.

Good luck finding a manual anymore. I just bought a 17 F-150 and would have liked a manual, but it can't come that way.

(I wanted it as a theft deterent device. Young folks today can't drive a stick, except for my kids. It is now a point of pride for them. For them, it was learn on a stick or don't learn as that was what we had.)

Notice we are talking about Dodges - can still get a manual in the 3500.

[transamz9]

Flashman wrote:

Lynnmor wrote:
Whatever floats you boat, but asking a transmission to operate at 1200 RPM while towing a load is what the engineers consider abuse and installed tow/haul mode for those that care.

Maybe I should have stayed with a manual tranny. They don't care what rpm the engine is running.

Neither does the auto really. I have the same running gear as you and I see zero difference in fuel mileage between 5th and 6th towing. I tow 20k with mine.

[Bobbo]

Flashman wrote:

Lynnmor wrote:
Whatever floats you boat, but asking a transmission to operate at 1200 RPM while towing a load is what the engineers consider abuse and installed tow/haul mode for those that care.

Maybe I should have stayed with a manual tranny. They don't care what rpm the engine is running.

Good luck finding a manual anymore. I just bought a 17 F-150 and would have liked a manual, but it can't come that way.

(I wanted it as a theft deterent device. Young folks today can't drive a stick, except for my kids. It is now a point of pride for them. For them, it was learn on a stick or don't learn as that was what we had.)

[Flashman]

Lynnmor wrote:
Whatever floats you boat, but asking a transmission to operate at 1200 RPM while towing a load is what the engineers consider abuse and installed tow/haul mode for those that care.

Maybe I should have stayed with a manual tranny. They don't care what rpm the engine is running.

[Lynnmor]

Whatever floats you boat, but asking a transmission to operate at 1200 RPM while towing a load is what the engineers consider abuse and installed tow/haul mode for those that care.

[wanderingbob]

Today I hauled a 4,000 lb flatbed from Tally to P-cola , empty, just for a test I ran with tow-haul at 67 MPH . No problems everything normal . Coming back with 8,000 Lbs of lumber I found that my transmixer would not shift into sixth gear at my loaded speed of 62 mph , tack said 1,700 rpm . Turn off tow haul and I could run at 62 tacking at 1,200 rpm . To me that sounds better , same speed with a large difference in RPM . I have been running like this for many years with three different Rams , First two I traded above three hundred thousand miles .I do not believe that I am hurting these trucks .
As we must keep a log book , going faster will not help as we will "time out " before we can do but one 400 mile RT per day . At sixty two MPH I get real good mileage , going faster does not help me a bit .
As far as more aggressive braking goes , who needs it as I never run aggressively and 99% of the time I am on a rural road , I do not need the interstate highway and do not drive them unless someone has a pistol to my head ! Every driver is different and our needs are different !

[Ron3rd]

dfletch wrote:
I use Tow/Haul any time the trailer is attached. As stated above exhaust break works better.

X2, I'm of the belief the computer is smarter than I am....

[Atlee]

Tow/haul or not, the single biggest factor that affects my fuel mileage is the speedometer.

I notice little if any change in mileage when in Tow/Haul. However, I easily notice a difference if I'm driving at 65 mph and 55 mph.

hawkeye-08 wrote:
Yes, Tow/Haul reduces my fuel mileage on rolling hills. I normally run it though when towing.

[SweetLou]

Cummins12V98 wrote:

wanderingbob wrote:
Wow , wow ! Only use tow/haul when necessary . I tow every day in flat Florida , no tow haul necessary unless it is a heavy trailer . People who use it 100% of the time must live in mountains or something . I spot trailers mostly in the south and each trip is different . Your load should determine what gear to use ! A fellow who works beside me in the same kind of truck uses more than 10% more fuel than me when he uses tow haul . We deliver and move trailers for construction , manufacturers , and hot shot deliveries .
Only use what is needed , most times your truck will tell ya what you should be doing ! Why would use it if not needed . If the truck manufacturer thought it should be on all the time maybe he would have made them that way !

You may want to go tom the TDR and do some reading. Increased line pressures, being in the right gear for optimal acceleration and keeping the turbo exercised and having brake pads last WAYYY over 150K just to name a few reasons.

X2

[DanNJanice]

I find tow/haul mode to be overly aggressive with the downshifts. I leave it off most of the time and just lock out the upper gear(s) if in hilly/mountainous country.