Question Driving Tips for Towing and MPG

[troutwest66]

Since I'm new to the 6.0 and the auto tranny I had some questions I was wondering about.

1. For MPGs what seems to be the sweet spot RPM wise? 2000 RPM and under was in my IDI but the 6.0 has a much higher redline so I'm not sure on this one.
2. With the Tow/Haul mode can I use it anytime for downhill speed control like an exhaust brake? I don't want to add undue stress to the tranny. The owner's manual isn't THAT helpful. In the woods hunting I'll just drop it into a lower gear. Does anyone use it going uphill towing? We have a 5-7% grade over 4th of July Pass on I-90 heading east into the Silver Valley to go camping. I'm not expecting an issue going down the hill but I've never towed or hauled a camper with an auto.

I thought I would learn from others' experiences to shorten my trial and error.

Thanks in advance!

 

[DaveBen]

Tranny first. I use two/haul when I want an exhaust brake. It works up and down hill very nicely. Play with it until you get the feel. You will not hurt the tranny unless you do something stupid. Remember this ONE RULE: brakes are a lot cheaper than a transmission. I use tow/haul sparingly and mostly under load. Otherwise I use the brakes. AND they work great
Second, speeds. I drive at 70 mph all of the time, unless the limits are higher, and I get 18 to 19 mpg. It goes downhill if I go faster. I have 3.37 gears. I have gotten 21.9 mpg, driving 55 mpg, ONCE over 70 miles distance. I don't do that any more.

Dave

 

[01yellerCobra]

Dave, is that mpg unloaded or loaded?

Misspelling brought to you by Tapatalk

 

[WD40]

My Fifth wheel is a little over 16,500 so I drive with tow/haul on all the time. Dave I think you mean 3.73s don't you. I would kill for that kind of MPG.
Doug

 

[DaveBen]

You are correct, my fingers got it wrong; 3.73 gears and my mpg trial was unloaded.

Dave

 

[BIG JOE]

Another .02* ?

I use Tow/Haul anytime I'm hooked up to anything. (a 6.7 guy... but the basics apply ?)

Pulling a grade: I use whatever gear it takes to keep the RPM's between 2K and +/- 2500**.

Going down a grade: I use whatever gear it takes to keep the RPM's Below 3K and let it Drift... with light to medium braking.

Joe

*Alwayz remembering.. It's not how FAST I go up or down a grade... It's how WELL I do it. (with Safety, the Traffic and my Equipment in mind)

** most of the time.. with the CC on.. @ 62 MPH.. watching the EGT's.

 

[snicklas]

I actually use Tow/Haul mode in all kinds of situations......

In winter (I'm in Central Indiana, so it does get cold here) I will use THM to keep the RPM's up to help warm the engine faster.

I have also used it while driving in snow for more control over the available speed and power in 2x and 4x4 driving

My M-I-L Lives in the foothills of Southeastern Kentucky, when I get off the interstate and hit the windy, hilly country roads, I use THM, better control of speed and braking.

When I was towing my 21' 5000lb Travel Trailer, I would get ~15 towing, running the posted speed limit. I have seen as high as 21 with just the truck, in the heat of the summer, running ~75MPH with the A/C on MAX!!!!

 

[troutwest66]

Thanks for the tips. I have 3:73s as well (2000RPM at 70MPH). I haven't had a chance to do any mileage calculating yet. Our trailer is an '88 Prowler 18 foot. We usually have the '03 Yamaha Grizzly in the truck when camping. I was thinking flatland towing I wouldn't need tow/haul but going down the grades I might if an extended distance and I needed to slow things down. I don't like riding brakes down hills but I'm okay with braking then releasing as I go so as not to heat things up too much. So, basically experiment to see how it goes? Pulling a grade loaded keep the RPMs between 2000-2500 then? Sounds good. A bit of a learning curve here. You wouldn't think going from manual to auto would be so difficult!! Any improvement in mileage traveling at 65 vs. 70? If not, 70 it is!

Thanks again for the replies. Any other bits of wisdom I'm all ears!

 

[snicklas]

...I was thinking flatland towing I wouldn't need tow/haul but going down the grades I might if an extended distance and I needed to slow things down. I don't like riding brakes down hills but I'm okay with braking then releasing as I go so as not to heat things up too much...

My rule of thumb has been (I've had this truck for almost 9 years) is if there is something connected to the hitch (a trailer, not my hitch-packer) it's in Tow/Haul Mode. This is even with my ~1000lb IH Cub Cadet on my 5x8 Flatbed trailer. Or depending on conditions as I listed above.... The Tow/haul Mode is much different than the old O/D Off button. The O/D Off did just that, you don't get Overdrive anymore.... with Tow/Haul Mode the transmission still uses all 5 gears, it will keep the converter locked, and not release the coast clutch so that you have engine braking, like downshifting in a manual.

Don't be scared to play with Tow/Haul Mode. The transmission will be just fine.......

 

[troutwest66]

Thanks, Scott. That's reassuring. I didn't know if RPMs and speeds were affected. If I'm processing all of this correctly with a trailer the shift points are a little different but highway speeds are all the same once underway? I can do that! I've been such a die hard gear rower for so long I just don't want to goof anything up. Thanks for all of the help.