Towing with a 200-series Toyota Land Cruiser (2 Viewers)

[skrypj]

This is crazy to me. I know y'all deal with these kinds of temps if you're doing work with your 200, which I fully support.

But once I installed a cooler, I've never seen pan temps over 210 in my Tundra, no matter what I'm pulling or at what altitude. I stick to S4 unless on flat highway. My 6 speed locks up in 4, 5, and 6.

Is it a combination of a bigger cooler up front and higher gears in the axles in my Tundra? Is the lockup programming different?

Why do Tundras with the same engine/transmission run significantly (~10%) cooler? Some of the guys on the Tundra forum who pull 8k report that, counterintuitively, their trucks run cooler with the thermostat pinned open. I would think there would be no difference once you're past the point of it opening, but maybe it doesn't open all the way on its own until you're at very hot temps. Mine seems to open at 195 and stays there unless I'm doing work.

The guy you are responding to also has an 8 speed so its not the gears. The 4.30’s in the tundra are just compensating for the ridiculously tall transmission ratios. My 6 speed F150 had shorter overall gearing with a 3.55 axle than a tundra does with 4.30’s.

If the thermostat is like a coolant thermostat then it probably doesn’t fully open until 15-20* hotter than the temp it cracks at. I had a remote oil cooler on my F150 from improved racing and they suggested running a ~200F stat to give me a target 215F oil temperature.

Why the LC runs hotter idk. It has a pretty large cooler from the factory. My GX460 also never passed 208 once I added a cooler. My LX sees temperatures with its big factory cooler, that my GX was seeing with no cooler at all.

 

[LX Cruiser]

The Tundra is not fulltime 4wd. I assume that has a little to do with it? Also, the Tundra I assume weighs less?

Maybe the fulltime 4wd has something to do with it? But no, they weigh about the same. My truck’s door jamb and my LX’s door jamb are very close:
Tundra: GVWR - 7200 lb, payload - 1270, GAWRs 4000/4150
LX: GVWR - 7275 lb, payload - 1235, GAWRs 3595/4300

The guy you are responding to also has an 8 speed so its not the gears. The 4.30’s in the tundra are just compensating for the ridiculously tall transmission ratios. My 6 speed F150 had shorter overall gearing with a 3.55 axle than a tundra does with 4.30’s.

If the thermostat is like a coolant thermostat then it probably doesn’t fully open until 15-20* hotter than the temp it cracks at. I had a remote oil cooler on my F150 from improved racing and they suggested running a ~200F stat to give me a target 215F oil temperature.

Why the LC runs hotter idk. It has a pretty large cooler from the factory. My GX460 also never passed 208 once I added a cooler. My LX sees temperatures with its big factory cooler, that my GX was seeing with no cooler at all.

Yeah, one would think the 8 speed would run cooler. But it seems 200s—whether with 6 speeds or 8 speeds—run consistently hotter than Tundras when doing the same work.

Regarding 4.30s, Toyota offers far fewer drivetrain options and does what they need to do to make it work across a variety of platforms. That meant putting the same transmission in multiple vehicles and changing axle gearing based on projected use. Lots of 200 owners go to 4.30s as well. If I keep 285/75s on the truck, I might just get 5.29s and bring it back to stock snappiness.

Maybe NKP is onto something with the fulltime 4wd. I also wonder if it’s an airflow thing with the 200s. There is a lot crammed into a smaller space. If you’re running cat skids, you’re probably not helping with the airflow.

 

[skrypj]

Maybe the fulltime 4wd has something to do with it? But no, they weigh about the same. My truck’s door jamb and my LX’s door jamb are very close:
Tundra: GVWR - 7200 lb, payload - 1270, GAWRs 4000/4150
LX: GVWR - 7275 lb, payload - 1235, GAWRs 3595/4300

Yeah, one would think the 8 speed would run cooler. But it seems 200s—whether with 6 speeds or 8 speeds—run consistently hotter than Tundras when doing the same work.

Regarding 4.30s, Toyota offers far fewer drivetrain options and does what they need to do to make it work across a variety of platforms. That meant putting the same transmission in multiple vehicles and changing axle gearing based on projected use. Lots of 200 owners go to 4.30s as well. If I keep 285/75s on the truck, I might just get 5.29s and bring it back to stock snappiness.

Maybe NKP is onto something with the fulltime 4wd. I also wonder if it’s an airflow thing with the 200s. There is a lot crammed into a smaller space. If you’re running cat skids, you’re probably not helping with the airflow.

Yeah, I hear you. Maybe it’s the tow/haul mode In the tundra locking up the torque converter more. Because my transmission temp is nice and cool at around 200F until I hit 4th gear then the TC unlocks. Then it starts to gradually climb until I get up into the 240’s. Thats as high as I have seen so far.

I plan to go 3.91’s just to try to keep my truck out of 4th more.

 

[Artie]

This is crazy to me. I know y'all deal with these kinds of temps if you're doing work with your 200, which I fully support.

But once I installed a cooler, I've never seen pan temps over 210 in my Tundra, no matter what I'm pulling or at what altitude. I stick to S4 unless on flat highway. My 6 speed locks up in 4, 5, and 6.

Is it a combination of a bigger cooler up front and higher gears in the axles in my Tundra? Is the lockup programming different?

Why do Tundras with the same engine/transmission run significantly (~10%) cooler? Some of the guys on the Tundra forum who pull 8k report that, counterintuitively, their trucks run cooler with the thermostat pinned open. I would think there would be no difference once you're past the point of it opening, but maybe it doesn't open all the way on its own until you're at very hot temps. Mine seems to open at 195 and stays there unless I'm doing work.

Mine is a 8 speed but cruiser weight and larger tires (34 inch) is my issue. Depending on the climb there is a power hole where you’ll need 3500 or more rpm’s to maintain speed, less that 3500 rpm’s and your dropping speed. Throw some curves or a slow mofo in your way killing your momentum and you’ll find yourself in the power hole easily. The climb I took this picture is not even that steep, it’s several miles but twisty so you struggle to maintain speed.

I need to make the jump to 3.90’s eventually. I’ll do 30k trans fluid changes until then.

 

[skrypj]

Mine is a 8 speed but cruiser weight and larger tires (34 inch) is my issue. Depending on the climb there is a power hole where you’ll need 3500 or more rpm’s to maintain speed, less that 3500 rpm’s and your dropping speed. Throw some curves or a slow mofo in your way killing your momentum and you’ll find yourself in the power hole easily. The climb I took this picture is not even that steep, it’s several miles but twisty so you struggle to maintain speed.

I need to make the jump to 3.90’s eventually. I’ll do 30k trans fluid changes until then.

I got into that hole the other day. I ended up at 50 mph with my foot buried in the carpet.

 

[Nothinghead]

I got into that hole the other day. I ended up at 50 mph with my foot buried in the carpet.

Th problematic hole I’ve found is the gap between gears 2 and 3.

 

[skrypj]

Th problematic hole I’ve found is the gap between gears 2 and 3.

Yup, exactly. I was in third at probably 3600 rpm and 2nd was to much of a jump

 

[TeCKis300]

I think there's several of little things adding up, which makes the Tundra tow better and cooler, even with same engine and transmission. The drivetrain just has to work harder with less cooling in the 200-series.

1. Yes, RWD with less parasitic load
2. Tundra tranny aux cooler is 22% larger
3. Available tow package with 4.3 gears
4. Smaller 275/65R18 tires
5. ~500lbs lighter curb weight (5,170 to 5,680lbs) vs LC/LX (5,715 to 6,100lbs)

Adds up to give the Tundra more towing capacity with the same drivetrain.
Tundra - Tow Capacity: up to 10.2k, GCWR: 16k
200-series - Tow Capacity: up to 8.5k, GCWR: 14.4k

I have Tundra 4.3s but that doesn't really give me an advantage as it's to correct for 35s. I think the 200-series transmission temps are fine for 90% of people that tow and the numbers being thrown around here aren't anything excessive. I expanded mine as I'm towing past factory GCWR at 15.6k lbs, and I do trip the stock lockup protection.

DIY Aux Transmission Cooler

As the stock 200-series already has an aux tranny cooler, perhaps this is better described as installing an aux aux cooler. The stock cooler is solid. I imagine this is niche for the heaviest of rigs or those that do more aggressive off-road running that really loads up the torque converter...

forum.ih8mud.com

 

[LX Cruiser]

I think there's several of little things adding up, which makes the Tundra tow better and cooler, even with same engine and transmission. The drivetrain just has to work harder with less cooling in the 200-series.

1. Yes, RWD with less parasitic load
2. Tundra tranny aux cooler is 22% larger
3. Available tow package with 4.3 gears
4. Smaller 275/65R18 tires
5. ~500lbs lighter curb weight (5,170 to 5,680lbs) vs LC/LX (5,715 to 6,100lbs)

Adds up to give the Tundra more towing capacity with the same drivetrain.
Tundra - Tow Capacity: up to 10.2k, GCWR: 16k
200-series - Tow Capacity: up to 8.5k, GCWR: 14.4k

I have Tundra 4.3s but that doesn't really give me an advantage as it's to correct for 35s. I think the 200-series transmission temps are fine for 90% of people that tow and the numbers being thrown around here aren't anything excessive. I expanded mine as I'm towing past factory GCWR at 15.6k lbs, and I do trip the stock lockup protection.

Agreed. Regarding #2, they dropped the cooler altogether on the 19-21 models. I added a large Hayden to mine, so it’s definitely not apples to apples on that front. My bare bones crewmax (cloth seats, no sunroof) is 5900 lb bone stock according to the door jamb, but Toyota has been very much known to overestimate curb weight on Tundras. I put LT285/75R18s on it and a retractable bed cover with a dual battery setup for our fridge. So she’s definitely a fatty now.

 

[TeCKis300]

Agreed. Regarding #2, they dropped the cooler altogether on the 19-21 models.

Yeah, I think it wasn't a great idea that they dropped the cooler in later models. But it also suggests they were comfortable and validated that the latest tranny fluid formulations hold up well to higher temperatures.

I do wonder if the Tundra radiator is also larger.

 

[skrypj]

Yeah, I think it wasn't a great idea that they dropped the cooler in later models. But it also suggests they were comfortable and validated that the latest tranny fluid formulations hold up well to higher temperatures.

I do wonder if the Tundra radiator is also larger.

In my quest to figure out why my Ecoboost would overheat so easily, I started recording radiator core sizes from different trucks to compare. I believe the stock tundra is 25.56” x 27.75” x 1.26” HxWxD

I’ve not measured my LX core

Edit, actually, I had the 2008+ LC core size written down as well. 23.25”x28.13”x1.26” so it s a little smaller.

But I find the radiator size thing to be a tough one for me to buy. My F150’s trans temp never went over ~208 with a similar sized cooler to the LC200. My F150’s radiator was only 16.5”x31.5”x1.26” and I would regularly see coolant temps in the 230’s and 240’s and my transmission was always totally fine. In fact, I had a thermocouple just after the outlet of my radiator and my “cold” coolant would sometimes be leaving the radiator at 208-210F, just as hot as the trans fluid was.

At one point, in an effort to offload some heat from the coolant, I bypassed the transmission cooler in the radiator end tank and ran just the air cooler and found almost no difference in transmission temps. It pretty much stayed between 201 and 208F all the time.

 

[TeCKis300]

In my quest to figure out why my Ecoboost would overheat so easily, I started recording radiator core sizes from different trucks to compare. I believe the stock tundra is 25.56” x 27.75” x 1.26” HxWxD

I’ve not measured my LX core

Edit, actually, I had the 2008+ LC core size written down as well. 23.25”x28.13”x1.26” so it s a little smaller.

But I find the radiator size thing to be a tough one for me to buy. My F150’s trans temp never went over ~208 with a similar sized cooler to the LC200. My F150’s radiator was only 16.5”x31.5”x1.26” and I would regularly see coolant temps in the 230’s and 240’s and my transmission was always totally fine. In fact, I had a thermocouple just after the outlet of my radiator and my “cold” coolant would sometimes be leaving the radiator at 208-210F, just as hot as the trans fluid was.

At one point, in an effort to offload some heat from the coolant, I bypassed the transmission cooler in the radiator end tank and ran just the air cooler and found almost no difference in transmission temps. It pretty much stayed between 201 and 208F all the time.

Awesome data there. Thx.

Converting to volume, Tundra (894 cu in) vs 200-series (824 cu in) vs F150 (655 cu in)

Compared to the 200-series, the Tundra is 8% larger, and F150 is 27% smaller.

The 200-series coolant temp is imminently stable in low to mid 190* F. Evening caning the throttle for 10+ minutes at a time towing on grade, I've never seen it over 203*F. I always wonder how front bumpers and under armor might affect flow and max cooling capacity.

 

[skrypj]

This is my full dataset:

 

[Boston Mangler]

Curiousity Question For Yall

Having owned, and flogged a few Tundras, one of which i towed way more than i should have, i did always monitor temps and no alarms.

I take most forum info with grains of salt until verified, but TONS of people on the Tundra forums had mentioned the grill choice effected tranny temps 10-15 deg.

Those that towed heavy claimed the TRD pro grille allowed MUCH more airflow and in turn, ran more fresh air through the tranny cooler, and in turn running cooler temps.

If you google Tundra grills, there are many even OEM, youll see what i mean, some of them appear to have considerably more open space / airflow that others.

Any chance this actually plays into the temps and cooling? I honestly dont know. In theory, seems it might, but i also think engineers know more than me

Thoughts?

 

[LX Cruiser]

Curiousity Question For Yall

Having owned, and flogged a few Tundras, one of which i towed way more than i should have, i did always monitor temps and no alarms.

I take most forum info with grains of salt until verified, but TONS of people on the Tundra forums had mentioned the grill choice effected tranny temps 10-15 deg.

Those that towed heavy claimed the TRD pro grille allowed MUCH more airflow and in turn, ran more fresh air through the tranny cooler, and in turn running cooler temps.

If you google Tundra grills, there are many even OEM, youll see what i mean, some of them appear to have considerably more open space / airflow that others.

Any chance this actually plays into the temps and cooling? I honestly dont know. In theory, seems it might, but i also think engineers know more than me

Thoughts?

I’ve had a few different grilles and monitor temps all the time. Current grille is the old style TRD Pro with one giant bar across it. I was worried it might impede airflow, but I’ve noticed no change. Previous grille was the honeycomb.

Here’s my Hayden cooler.

 

[skrypj]

I’ve had a few different grilles and monitor temps all the time. Current grille is the old style TRD Pro with one giant bar across it. I was worried it might impede airflow, but I’ve noticed no change. Previous grille was the honeycomb.
View attachment 3661426
Here’s my Hayden cooler.
View attachment 3661425

If you read Corky Bell’s Maximum Boost, he says you actually want the opening to your cooler to be slightly smaller than the cooler. All the fins and tubes and stuff make the flow area smaller than the actual radiator size, plus you’ve got the fan shroud behind it.

So as long as the grill has as much flow area as the fan shroud, you are good.

 

[TeCKis300]

Figure this audience might be interested. Good deal today on Harvest Host memberships. Free nights stay at some pretty awesome private places. Great for passing through

 

[Boston Mangler]

Figure this audience might be interested. Good deal today on Harvest Host memberships. Free nights stay at some pretty awesome private places. Great for passing through

View attachment 3661956

Damnit dude….

This was my little secret to peace and quiet camping

 

[TeCKis300]

Damnit dude….

This was my little secret to peace and quiet camping

Just wait until I post it on the gram.

 

[Boston Mangler]

Just wait until I post it on the gram.