I have a 1999 XLT 4x4 and sometimes tow a boat on level roads. I usually tow in overdrive but if I tow in drive how much will my mileage suffer ? I have a 4.6 v8 and tow a 1600 # bassboat
Thanks

 

The real question is how much will your tranny suffer if you continue to tow in overdrive. Since i put my 35" swampers on i have been keeping my truck out of OD. City mileage stayed the same, HWY driving dropped about 3 mpg, but i think some of that is from the bigger tires. So i would gues you would only lose 1 or 2 mpg.

-Jon

 

I just bought a new 150 SC w/ 5.4, 3.55LS, and we drove about 500 mi round trip this past weekend. Mileage was approx 16 running in overdrive. At 70 mph, the rpms were around 2000. When I turned off the overdrive the rpms increased about 1000 so the mileage would definitely suffer. I only ran engine up to 3000 a couple of times since its new.

 

Your mileage will be worse with overdrive locked out. I have noticed this. I would guess about 3 mpg difference. With only towing 1600 lbs though, I don't think I'd worry about it. That isn't a whole lot of weight and as long as your tranny isn't shifting in and out of overdrive all the time you won't cause any damaage with that small of a load. If you are towing much more than that, I'd lock it out of OD just to be safe. I personally haul a 2000 lbs camper and leave OD on most of the time. I've got over 110,000 miles with no problems to date.

 

Hey Primetime.
Better knock on some wood...
I tow without the OD on.
Makes me feel better. I'd rather pay the extra
Gas now than a tranny later...
Also, everyone should think about switching to
Mobil 1 or Amsoil ATF Fluid...Much better and will
never get as hot...
Good Luck

 

I would have to agree, especially after hearing a local auto talk show host that syn tranny fluid will definitely extend the life of auto trans. He has mentioned numerous times that the ford auto trannies do work and shift harder, meaning that fluid temp tends to run hotter than other brands of vehicles. Syn oil is much more duable at higher operating temps than natural oils.

 

1600 pounds? Relatively flat towing?

Forget about it!

If these trucks can't tow that in Overdrive then I should turn off the Overdrive when I'm hauling my mother-in-law around.

If the trans is huntin' turn off the OD, udderwise forget about it.

 

The fluid required by the 4R70 tranny is Mercon V which is already synthetic...

 

So other than towing (especially with heavier loads) are there any other situations you would be better off to turn OD off? (other than climbing a mountain or something) Although I know all too good and well to not listen to everything you hear, I've been told OD is only advantageous on the highway, and acually cost you milage in the city and in the rain. Is there any truth to this?

 

"In the rain" ???

OK to tow in OD as long as the tranny is not hunting from OD to 3rd

 

Don't use OD in the rain? I don't get it.

I use the OD lockout if:

1. Tranny hunts from OD to 3rd. Generally on long grades or mountain driving
2. Engine braking down mountain grades - truck holds a steady 65-70 mph down the grades into Denver - never need to tuch the brakes.

I'll tow a trailer in OD so long as it doesn't hunt.