Re-Gear for towing

No towing with overdrive gears, so you'd be topped out in 4th gear when towing anyway.

 

Maybe it isn't as good as a 3/4 ton full size, but it does an admirable job as long as you treat it right. No drag racing off the green light or trying to pass when you're already at 60, that kind of stuff, and plan on more frequent transmission fluid changes. I've been towing frequently and in the upper third of the rated weights for over 6 years with my 2011. Heck, the bed is so small I have to tow in order to haul anything worth carrying. I've got 145K on the truck and do trans services every 30K. I bought the truck with 60K on it in 2017. I pull a 18' flatbed with a tractor that fully equipped (loader and tiller or box blade on back) weighs about 4500 pounds and the trailer weighs 1800. I also pull a 6'x10' tandem dump trailer that weighs 6500 pounds fully loaded. That's the rated limit for my truck. Both trailers have brakes. I can tow in 90 degree temps and keep my trans temp at 210 or less if I watch when I'm on a hill. My tires are oversize (265-70-17) so I'm effectively running higher drive ratios (lower numerical). I can comfortably run 60 mph with the tractor or dump trailer and keep engine temp below 200 and trans temps about 185 unless I hit a hill. Locally, I will manually shift into 3rd earlier than the transmission does and running the engine up to 3500-3750 keeps it pulling nicely, I don't have to go more than that for anything I've hauled. I don't know how that equates to the 3rd gen with its smaller engine, even though it is rated higher than the 4L I have.

Towing in overdrive isn't a good idea in many trucks. My previous truck was a K3500 GMC diesel with the 4L80E transmission, a real towing beast. I never towed in OD with it because it never stayed in OD, it was always hunting. Overdrive typically keeps the engine speed below its torque peak, so a heavy load will always keep it shifting.

 

All-around driving experience really depends on how much time you are towing. Thanks to a re-gear in my 2nd gen from 3.73 to 4.56 and only 32 inch tires, towing acceleration and such is good, but driving unloaded gets HORRIBLE gas mileage, lol. Unloaded driving 55 mph I'd probably be lucky to get 13.5 mpg. Luckily, I don't use my truck unloaded very often anymore. I'll drive the wife's 50+ mpg car most days and leave the truck for towing/camper hauling.

 

Seems like something else is up on yours. The stock manual transmission 2nd gen does 2511 rpm at 70 when fully stock. Your truck with the auto and 32's geared to 4.56 should be turning the same rpm (2512) at 70. I don't see why your mpg would be any worse than a stock manual.

The 3rd gen is a different animal anyways, the gearing is crazy tall comparatively and the 3.5L needs to rev.

 

My main point is the trade-off. You'll lose some of your freeway low-rpm cruising ability, as you'll be running higher revs in 6th. If never in that situation, not a big deal.

My truck's heavy E-loads and added 600+ pounds of armor/winch aren't helping much. Not to mention loss of aerodynamics.

You're spot on on my gear ratio being same as the Manual 6sp. So odd though. They're both rated the same (as far as I can find) for gas mileage, yet the manual (or my auto) is turning 18% higher rpm than the stock automatic.

 

In my experience, rpm doesn't make much difference at all in mpg until you reach the extremes. My stock 3G manual turned 2450 rpm in stock form at 70, and I regeared it on the stock trans and tires which put it at 3000. Staying at 70, I got the same 17-18 I always got. It started to drop to 14.5-15 pushing over 80, but stock didn't do much better at 80 really either.

Where rpm seems to make a difference is on a low rpm setup with the wind at your back. I had a loaner automatic 3G for a few weeks and I took a road trip in it. Those turn like 1750 rpm in 6th gear, which is extremely tall. I got 15-16 mpg going where I was going, into the wind. On the way back, I got 22 mpg, with the wind helping. When the wind helps me in the manual, I only get maybe 18 or so. But headed into the wind, I get the same 15-16. So really where rpm seems to hurt me is when the wind is helping me, the rpm ends up wasting some of what could have been saved. In other words, during times when turning the extra rpm needlessly. In general driving it doesn't seem to hurt me at all because it can often be more or at least as efficient by working more lightly but at a higher engine speed. Meaning it sort of balances out in normal driving.

 

Well here goes, I pull a Sunline T1700 it's right around 3700 LB with a 4L Tacoma it is a 6 manual yes I can drive it in 6th at 60 MPH on mostly flat ground. Now I'm sure you will call BS but I can get 14 MPG on the flat in 6th. Yes hills put a hurt on it going up though the presidential in NH in some places I'm down to first or sec. and get out run by an old dog. It is bone stock. I have only been driveing pretty much any thing that moves for 50 years and I'm working on my forth million miles that may have some thing to do with it.

 

Wouldn’t regear take 5th and essentially make it the new “4th”. and I’d actually be able to utilize 6th gear

 

No, you want to be careful with any truck towing in overdrive gears because the torque converter won’t stay locked up and transmission temperatures can skyrocket. Of the road is completely flat or just slightly downhill I will sometimes bump it into 5th gear as long as it will hold the gear and not try to downshift. I do have a gauge that shows trans fluid temps which is a good idea to have while towing.

 

Thanks for all the input. Sounds like an updated tune and and keep it in S4 while towing is the best thing to keep the transmission/torque converter happy