I know this is a bad idea but with the rpm at hi-way speeds in drive, my gas mileage is going to put me in the poor house, it already sucks. I've got the auto 4.6 with 3.55 gears. I'm looking to haul an atv trailer with 2 atv's total lbs. about 1500. Let me know if you would do this.

 

I had the same setup with my old truck, and didn't have too much problems with it. Hills maybe a little more difficult, just make sure you turn your OD off and I think that you will be alright with that load that you will be towing. Good luck.

 

When the tranny begins shifting in and out of OD, then turn it off - otherwise just leave it OD

 

Yeah, what he said.

 

Yeah OD is fine if the converter is staying locked, an open converter will generate a lot of heat.

 

I agree with the others, as long as it isn't shifting gears on you your fine when towing a heavy load. However I don't even consider 1500 lbs as a heavy load. 5-7000 lbs is where I consider driving habits when towing. I used to tow about 5000 lbs with a 4 cylinder ranger auto. I beat the snot out of that truck for years so you want have any problems with a 1/2 ton.

If I am towing (over 5000 lbs)and on a road going 40-50 mph I turn the overdrive off so it doesn't shift when I hit a hill or something. Any faster and overdrive is on.

 

Actually I've put on lots of miles towing a 21' 5'ver and the gas mileage is as good in 3rd as it is in OD. I have the 5.4 and at 65 mph the rpm is around 2750 which puts it right in the sweet spot for both hp and torque. I too haul a utility trailer with an atv and skidoo and road conditions dictate whether I tow in 3rd or OD. I find on the road up to my camp the truck is always shifting because of the hills so I drop it in 3rd and no problems. With the 3.55 rear end it doesn't take too much of an incline for the torque convertor to unlock but just play it by ear and you should be fine.

 

I've got the tune set up in my truck so the converter rarely unlocks, keeps the trans nice and cool even with no external cooler. Trans runs about 150F when doing 50mph and 170F when doing 75mph.