My truck doesn't do anything other than tow trailers these days. It makes the occasional road trip, but usually there is a trailer behind it. Trailers are tandem axle 7x12 enclosed, tandex axle 7x14 enclosed, and tandem axle 7x18 car hauler. My gearing is 3.55LS with the 5.4L engine. I switched from factory tires (265/70/17 ??) to 33x12.50x17 Cooper Discoverer STTs when I got the truck several years ago. Now I am contemplating going back to stock size highway tires to get some of the power back. It's got the Magnaflow exhaust and a K&N air filter currently, but I have held off on getting a custom tune so far. What would be better for the truck and it's towing ability - getting a tune or switching back to factory size highway tires?

 

Gears!

 

If your dead set on 33's , I would go with a 4.10 gear. But, you can gain 30/35 (max) adding LT's with the right set up behind them. You'll also benefit with an intake that smooths things out and works hand and hand with your exhaust. Air in and out. I suggest a good dry element for the intake (MAF) set up.

I like the 3.55's /3.73's w/stock 265's. So yea, 4.10's just seems right. One more add-on that should net you about 15 hp is E-fans. That's a 15 hp you'll notice right off.

I like the pace setters as far as headers, but it's personal preference and HF's of course.

Then a custom tune. That will wake her up.

 

Gears were my initial thought, but I don't know if I can justify spending $2k on regearing just so I can keep the 33s.

Jbrew - I am not dead set on the 33s...if going back to stock will bring the power/torque back to where it needs to be I will drop the 33s like a bad habit.

 

Well, I pull a car hauler once in awhile and my set up works for me. I'm running LT's and a intake. I also have a ported and polished upper intake, but that probably doesn't matter much unless yours is aluminum.

I beefed up the brakes as well. 272,000 miles and it's still doing it. I want to add e-fans .

You have more HP to begin with.

 

Gears. Even if you go back to a stock tire size gears will still help out a lot towing a heavy load. That or just put a lightning blower on it

 

That would do it. I would go for a roots blower before gears. Because w/3.55's, cruising Rpms are where I like them.

 

What part of the current towing performance don't you like?

Mitch

 

I hate to beat the dead horse and all, but yea, gears will make a significant improvement, even with your 33" tires. My truck is primarily used for towing my boat and weekend projects around the house. Even my pissy lil 4.2 V6 pulls very well after I installed 4.56LS and I too have 33" tires.

The initial cost is high but the long run pay off is worth it I think. Especially if you plan to keep the truck for years to come.

 

Ok so if I go the route of regearing what is going to be the best compromise between towing power/fuel economy/highway driving? I am not ever going larger than a 33x12.50x17 tire. I will honestly end up stepping down/over to a 285/70/17 on the next set because I am switching from a mud terrain to a highway/all terrain...

 

If you're staying at or just under a 33" tire I'd go with 4.10 for the best over all performance. I have 4.56 with my 33's but my highway RPM's a bit high for decent highway MPG's. My truck isn't a DD so I'm wasn't worried about highway MPG's

 

Mine isn't a DD either, but it does log a lot of highway miles on the weekends pulling trailers so MPG does matter. (I run a DJ and Event Lighting company that covers the entire state of Mississippi and lower Alabama and Louisiana)

This is why I was leaning heavily towards just switching back to stock size highway terrain tires - the truck never gets offroaded anymore. I bought a Honda Foreman to play with in the mud so the truck is only responsible for getting it there now.

 

Switch back to stock tires and see how it goes. Then if you want more *****, look at 4.10's.

Have you done a Gotts mod to your airbox yet?

No matter what you do, a programmer with the right tunes will help.

 

I agree. Thing is, if you pull over 3000 lbs and your running the high way, your not using OD. Depending upon how fast you like to pull, 4.10's or not, your going to want the rpms down in 3rd @ HW speeds. I just saying that because the 5fours really like the fuel @ higher rpms, and generate their torque on the low side. So 4.10's might get old quick lol. With 3.55's pulling a hauler @ 70-75 mph, I'm about 2500-2700 w/265's. 4.10's would work against me as far as HW speeds. That's why I optioned out and added more power and torque. LT headers was a cheap and easy way to add 30 horse and 35 torque. Plus I can keep up with traffic accelerating normally.

Gears can be expensive and you really have to trust the person who's setting them up for you.

BUT, like I said before, - if your keeping the 33's .... And/or you do allot of city miles, it may make more sense to jump up the gearing.

A tune for your model does wonders for shift points and AF's. Specially on a tow tune. You can get custom tune for the amount of weight you generally haul. Hell, you can get more than one tow tune for that matter. Depends on what you want I guess, - how much you want to invest. I'd invest in a "Roots" blower before gears, but that's personal preference and tire size.

 

That's why I asked what he didn't like about his current towing performance...

Is it the way it pulls from a stop, or the way it cruises down the hwy, or how it pulls the grades??

My 5.4 likes to cruise down the hwy pulling around 2200-2500 rpms in 3rd gear and going between 60 and 65 mph..

Up the grades, it'll go into 2nd and pull around 3500 rpms to go 55 mph.

From a stop, I give it enough gas to get moving and then adjust for the speed limit and try to get the TC to lock as soon as it can.

Pulling 2500 rpms in 3rd gear is the same as pulling 2500 rpms in OD and around 2500 rpms is where your engine is making it's peak power, so that's what you should shoot for IMO...

Mitch