I've been poking around here for a bit, but never posted before. My question is towing based, so that's why it's here instead of the programmer/chip section.

1997 Supercab
4.6L
Auto
4x2
3.55 gears I think (non LS I know)
68000 miles
265/70 - 16 Tires (235/70-16 was stock)
K&N filter, and cut out airbox.
Bosch Platinum +4 plugs

I've flat towed my Jeep (around 3,500 lbs) about 400 miles once with the truck as it is listed above and it did OK. OD was useless, even on flat road so I turned it off. With OD off, it pulled 3k rpm at about 70mph (speedo may be off due to larger tires) and I got around 9 mpg for the trip. This didn't really suprise me.

I now have a trailer to tow it with (1,500# est), so I'm thinking it will tow easier (5000# total est) since it won't have the resistance of the 35" tires on the Jeep and will probably follow better. I've towed it a couple miles just to see how it worked, but the trailer needs some work before I go any distance so it's hard to judge. The truck appeared to pull it fine for that short distance.

Now to my questions:

#1 - Does it seem reasonable that it would tow better on the trailer than flat towing even with the extra weight? Would I get better MPG while towing? (Assuming I dont' drive like an idiot)

#2 - I think a programmer would make it tow better, but noticed a warning on one of the websites stating that the peak performance setting was not for towing. Would it even be worth getting a programmer because all I'd get would be a little firmer shift, correct? Would I get better MPG towing?

#3 - Would an E-fan and catback make it tow substantially better with higher MPG while towing?

#4 - Do you think it would hold OD on flat ground with a programmer?

#5 - When unloaded I only get 14 MPG driving like a typical person (occassional hard take offs, 65 mph on highways, mostly in town) I would have thought it to be better. Thoughts?

Sorry for the lengthy post, but I'm new to Fords, and fairly new to towing anything for a distance. I probably should have gotten a 3/4 ton, but I also bought this for a daily driver to replace the Jeep and my budget was limited.

Any constructive comments would be appreciated.

 

You'll probably get about the same fuel mileage as the jeep is now higher and aerodynamics are worse on the trailer.

Your tires are almost 6% larger than stock which factors into your fuel mileage calculation as well as decreases mileage for the heavier tires.

You can check your axle code on the driver door sticker to find out the ratio. Search for "axle code" on here to find out what the ratio is. Getting a shorter gear (numerically higher) would be the cheapest way to get performance for a 2wd truck.

1) A balanced trailer should tow better (except for the exctra weight) than 4 down.

2) Superchip/programmer can have a towing 91+ octane program, but you won't get much fuel savings.

3) Efan and cat-back will yield power and sound, but I would not invest that kind of money on a 9 year old truck.

4) Probably not hold OD, nor would you get much fuel savings from that. The 4.6L is fine at 3000 rpm all day long. Fuel economy follows the accelerator pedal more than engine speed.

5) 14mpg is probably closer to 15mpg since you are driving more miles than your odo is indicating with the larger tires. Still that is a little lower than average, but well within reason. My 4x4 Screw w/ 285/70R17 and 3.73 gear yields 11-13mpg over the 33k miles since it was new.

 

Thanks! Your answers are pretty much exactly what I expected.

I forgot to mention that my fuel mileage I posted was corrected for the tires. It typically calcs out around 13mpg raw, and is closer to 14 once adjusted for the tires.

I've been driving a Jeep on 35" tires for 4 years now, and have kind of forgotten what a normal vehicle should do. The fuel economy worries me because I get 14 mpg in the Jeep after correcting for tires and gear ratio changes. I didn't expect a dramatic difference, but thought 16 would be reasonable.

I've thought about looking for a junkyard axle from a wrecked truck w/ 3.73s or better, but haven't really followed through. Working on Jeeps for the past 5 years has taught me not to be afraid of junkyard parts or driveline swaps.

Thanks for the input!