Tow haul mode questions

I’ve been driving a 04’ tundra access cab 4x4 first gen for around 300,000 miles since I purchased it new. Last year it was feeling her oats and spent a bunch of time in the shop. I love the truck but it’s falling apart and rusting to the ground. I’ve been using it as a dedicated work truck and during nasty weather.

last spring I bought a low miles 2.5 gen double cab 4x4 with essentially the same trim as my first gen. I put around 8,000 miles on both trucks in the last year.

Yesterday I drove the first gen 75 miles for work, then since I had more gas in the 2.5 I drove it around 100 miles in the evening for a errand. I drive like a grandpa, get the trucks up to speed and hit the cruise. Almost all highway miles. The 1st gen gets 16-17 mpg hwy and 12mpg towing. The 2.5 gen gets 18-19 highway and 12mpg towing. Anywho last night I hit the tow haul mode on a whim on the way home. It made the 2.5 truck feel just like the throttle response of my first gen. In the normal mode it definitely feels sluggish compared to the first gen. I see the tow haul mode shuts off restarting the truck.

My questions are

My first gen all tow haul seems to do is shut off the overdrive. Does the tow haul mode shut off 6th in my 2.5?

Secondly is there any reason I can just always run the truck in tow haul mode? Will it hurt anything after 300,000 miles? It’s just a different computer program right? Over the years I’ve only used the tow haul mode on the first gen towing heavy loads…

anyway it was a small moment of joy for me last night…the newer truck is much more comfortable with more room…but just a general sluggish uneasiness in throttle response…which I attributed to it being much bigger. I hit the tow haul mode and it felt just like my first gen…light and responsive.

 

It doesn't prevent the transmission from going to 6th gear in Tow/Haul mode. It does allow longer shift time particularly on lower gears and also some changes in the ecu calibration. You can drive it Tow/Haul all the time, it won't hurt it. I've been driving mine in S mode and Tow/Haul ON. Better control and in some instances, better mpg because I can accelerate the truck in lower gear more than in higher gear which the automatic loves to do.. This was even before I had the tune put in. Use good quality fuel.

 

No - tow/haul mode on your 2.5 gen won’t lock you out of overdrive gears - you have to put the trans in S4 to accomplish that. It does change the throttle mapping and shift points making it more responsive. Shouldn’t hurt anything running it in tow\haul whenever you please.

 

It will hold lower gears longer, so that when towing, you’ll have your rpm’s a bit higher in the rev range, providing more power when you need it. Throttle is more responsive as mentioned above. In normal mode the tranny shifts about 2000-2500rpm if you’re easy on the throttle. With tow haul mode on, it will rev out each gear higher. You’ll get worse fuel mileage using it, but it does make towing easier.

 

Search “Beast Mode” really wake that truck up

 

Ha! Just found that post on beast mode! I got in the truck and had to look all over though…the traction control off button is not on the dash. I had to get out a flashlight to find it tucked above the shifter to the right of all the USB ports. I laughed on the first post that mentioned “breaking it loose!” I’ll have to see if I can get it in beast mode now that I’ve found the button. It makes sense I like the tow haul as the first gen only has a few gears…it definitely has much longer shift points.

The only other thing that was bothering me was the truck slowing down when I feathered the throttle down to the stop like on my first gen. On the 2.5 there would sometimes be what felt like a hard downshift. I see from other posts on here that is normal. But in tow haul mode the 2.5 must do a little more engine breaking too as It almost stopped that hard down shift the way I drive. There are a few towns I have to slow down to 25-45 for half a mile and get right back on it where I’ve felt that weird down shift. I’ve never felt the first gen downshift slowing to a stop. It’s issue is at higher speeds 65 ish going up a hill or towing it would drop a gear and it would downshift and rocket off loudly with way higher rpm’s before getting the cruise off and off the throttle.

when I pulled in last night my “the trip fuel guess thing” that comes up after you shut the truck off with the tow haul mode wasn’t that far off from what I was expecting at 20.1 mpg. Gas mileage on short trips or with any idling is awful but the truck does reasonably alright for me on the highway.

Thanks for the help…it’s good to know it’s ok to use the feel good button. I’m gonna…

 

Tow/Haul = Tow/HaulAss

SPP

 

OP, that's because the truck is light and the Tow/Haul mode calibration is designed for heavily loaded or heavy towing. It's a more agressive calibration. Just be careful on aggressive driving. You could loose traction real easy and sometimes when that happens, the computer will cut power to the engine and basically makes the truck go limp for a second or so. Some forum members have found themselves in a hair raising experience as a result of this. They're trying to beat traffic crossing the road, guns the truck, tire spins, ecu reduced power to engine, truck slows own and traffic was about to hit your truck. You can turn off all the "nannies" but I don't trust it turning off completely. Although on my current truck 2010 4x4 Crewmax, I have weight on the bed. On my previous truck a 2007 Reg Cab 4x2 with 5.7, I also put weights on the bed. Traction is important.

 

Get a Pedal Commander, set it to the desired setting and forget about the laggy throttle and ever needing to push the tow/haul button. Throttle response will be perfect.

Search for the Pedal Commander here to see other's thoughts on it.

 

I got a used Hike It X5. Works great.

Toyota's ECU in the 2.5gen thinks it's smart... so the more you drive like grandma the more it screws up the throttle mapping. Feels like it's got 100hp til you practically hit the floor with the pedal... then all 400 horses come to life, the wheels spin... and the nannies kick in and slow you down again. It's incredibly annoying!

The Hike It fixed that... same as Pedal Commander and a lot of others. Super easy to install and adjust to taste. I don't think it effects shift points, but it let's you adjust the throttle map... and unlike the Tow-Haul button you don't have to turn it on.

 

I had a 2018 Tundra and now have a 2021 Tundra. I went from a DC to a CM, but I have 100% noticed that my '21 doesn't have the pep my '18 had. My 21' with Tow/Haul turned on feels like my '18 did with Tow/Haul turned off. Don't get me wrong, I love the truck, but I have definitely noticed that.

Maybe I should look into a Pedal Commander or something similar. Probably won't bother though. I don't drive like a grandpa, but I do drive pretty light on the accelerator compared to most people.

 

In my 21 SR5 the tow mode makes a dramatic difference in shfting and performance feel. Just my opinion.

 

If both trucks are stock, I still think you need to make sure you don't have a brake caliper or parking brake shoe lightly dragging. You were saying in another thread that it gets a few less MPG, too, right?

Fuelly still shows '21s doing almost half an MPG better than '18s (14.1 vs 13.7 tank average). Something might be slightly off on your truck.

 

For $170 or less, it's totally worth it. I don't think I could stand to drive it with the stock mapping. I like the throttle opening to be linear with the pedal.

 

Yep, good memory. I reset the trip and note my mileage every single fill-up and keep a spreadsheet, so I have all the numbers. Just an overall average maybe isn't entirely a fair comparison because life just has me driving different now with my '21 than I did with my '18 typically. But I can compare certain trips I would semi regularly make, and the top mileage is fairly different. The best tank I ever had with my '18 had 20.12mpg, all highway. The best tank my '21 ever had so far has been 17.08mpg.

 

Get something that can program your ECU like an HP Tuner instead of PC. You can configure your throttle angle to whatever you want. That’s basically what the Tow Haul button is, it changes your throttle angle by a few degrees.

 

I call tow/haul "turbo".

You can almost hear the gas being guzzled faster.

 

For someone that doesn't tow, the Gen 2.5 tow/haul button equals the hyperspace button...........



You'd have to have grown up in the early 80s to get it..

 

I think your first gen felt peppier because of your throttle cable? My last truck was an 02 ranger stick shift with a throttle cable, this truck is not only automatic but electric throttle. By comparison it's like screwing with a rubber versus raw doggin, night and day.

 

A little off topic, but my first throttle-by-wire vehicle was a 2007 Tacoma manual transmission. Liked the truck, but absolutely hated the throttle-by-wire. It did this RPM hang thing; when you had the RPMs up and you'd let off the accelerator to shift, the computer would let the RPMs hang and then slowly let it down. That went against everything I was used to; when I let off the accelerator, I expected the RPMs to drop. I'm sure this was fine with an automatic transmission, but it royally sucked with a manual.

I had it back to the dealership for it, complained to whoever would listen. The reason I heard was it was for emissions, to reduce unburnt fuel going out the tailpipe.

 

Asteroids

 

I think Asteroids only had 1 button

 

fire.... lol

 

More likely it was to help "rev match" in the manual to make shifting gears a smoother experience. Sounds like it failed in that regard for you.

 

Thought that was a more modern manual feature, like the 370Z's have

 

The more they try to "idiot proof" vehicles, the more they are only suitable for idiots...

 

Everything keeps getting dumbed down to the lowest common denominator. The "lowest" will keep getting lower as a result.

 

It's all about safety! If we could save just one life, wouldn't it all be worth it?

 

The fact that a manual transmission now qualifies as an “anti-theft” device says it all.