Towing with a 200-series Toyota Land Cruiser (3 Viewers)

[GBman]

Just want to run this by the more knowledgeable guys here. 2018 LC stock except for terra grappler G2 285/60R18 120S XL. Specs say max load 3086 @ 50 psi. I’m currently running toyota factory spec psi for daily use.

Towing ~30 foot boat. Gross weight is ~5-6k pounds it’s not my boat or I’d know exactly what it weighs. No real elevation to deal with.

1) should I air up to 50 psi before loading up?

2) do I need an aftermarket trailer brake connector or is that a factory item? I know I know rtfm. I normally only tow smaller lighter stuff. My father in law normally tows this boat with his old E350 v10. Trying to avoid bringing two vehicles as I’m not trying to ride in that guy.

 

[linuxgod]

No you shouldn't run at 50psi. There is an optimal PSI for the tire size which is designed to carry the rated axle weight. So long as you're not exceeding the axle weight you should use that pressure. If the G2s are p-metric then it's probably 33psi as stated on the door. If they are LT tires then it's 10% higher. @gaijin is the tire pressure master and will hopefully chime in.

Yes for any trailer over 1000# Toyota says you need a trailer brake controller. The LC does not come with one, though for the major vendors like Tekonsha you should be able to get the wiring harness with the Toyota connector on the end so it's plug and play.

 

[gaijin]

Just want to run this by the more knowledgeable guys here. 2018 LC stock except for terra grappler G2 285/60R18 120S XL. Specs say max load 3086 @ 50 psi. I’m currently running toyota factory spec psi for daily use.

Towing ~30 foot boat. Gross weight is ~5-6k pounds it’s not my boat or I’d know exactly what it weighs. No real elevation to deal with.

1) should I air up to 50 psi before loading up?

No need - you're good to go @33psi F/R.

HTH

 

[coleAK]

You need an aftermarket break controller if the trailer has e-breaks. It’s not to difficult to install but in no way easy, took me about 2 hours from what I remember. There is a walkthrough somwhere on this site.

 

[coleAK]

I’m on my 2nd Curt controller, first one lasted me 2 vehicles and 10 years. It does what it’s supposed to and adjusts well. Make sure you have at least a 3’ wiring connector as the port plug is way up there in the dash.

 

[GBman]

Thanks everybody for the help. It is much appreciated.

 

[TeCKis300]

1) should I air up to 50 psi before loading up?

I have a different take than those above. It's not only about load capacity. While I wouldn't do 50psi, I would absolutely go more than 33psi. Because with more pressure, there is more sidewall/geometric stability. A good thing when towing heavy loads. This is especially true for someone that's upsized the tire or towing on the heavier end. More sidewall equals more flex. We want less of that under tow.

I've done my share of road racing and autocross. Tire pressures there are less about load capacity than tuning for turn-in, feel, and grip. So my rear end is calibrated and dialed into tire feedback as I can easily tell a bump of a couple PSI.

It's the same under tow. There's absolutely a solid stability gain when going higher pressures. I'm on 305/55/20s. No trailer, a @gaijin approved 36psi. With trailer, 42 psi. Sometimes I don't get around to inflating the tires before I get underway on a trip. There's a notable difference in feel. It's never unstable without it, but it absolutely has that extra margin of stability with more air. Give it a try! My setup has nary a wiggle even with huge rigs passing alongside, or against on 2 lane roads.

 

[linuxgod]

I agree, though too much pressure will make the truck bounce over bumps in the road, which in itself can lead to instability or loss of control.

Side note: I run my rig at 38psi unloaded, 44psi under tow. I need to get to a weigh station but I am likely >GVWR when towing. I do have a heavier suspension over stock though, so I feel comfortable running that way. @gaijin mentioned in this thread that 45psi would be the correct tire pressure if I had the Australian GVM upgrade (+1200# GVWR increase to 2000kg front, 1800kg rear). I suspect when fully loaded for towing I'm at 7800#, which means ~42psi should be about correct.

 

[Romer]

I fill my tires without the trailer to 42 psi. Can't remember where, but there was data somewhere that showed it as appropriate for how heavy my vehicle is. I haven't added air when towing. Interesting conversation, nice to get other perspectives and additional data points to consider

 

[Dan Higgins]

Like, @Romer, I run my 285/65R18 E-rated KO2s at 42 PSI when not towing. Sometimes I increase the rear by a smidge (43 PSI) because that is carrying much more weight than normal whereas the front axle, if I get my WD correct, it slower to "normal". It was @gaijin that explained that the load range for the KO2s I have at 42PSI was good enough for not only normal driving but also with the trailer. But since I am slight exceeding the rear axle limit (with a stronger suspension) and the overall GVWR of the LC (by a few hundred lbs) I feel better with just a couple more PSI in the rear tires when towing.

 

[linuxgod]

Cross-posting from the "Do You Tow An Airstream" thread...

We did about 5000 miles going from Chicago to the LCDC and then through New Mexico and into Big Bend NP over the last few weeks. I now have a Trail Tailor front bumper with winch and the Lance 2185 is definitely 500-600# heavier than the old Surveyor 235RS.

I got anywhere from 6.5 to 7.5 mpg on my trip out west and back, typically going 70mph. My wife managed as high as 9.6 - not sure if she was going mostly downhill in OK or if she benefited by following an 18 wheeler for a couple hours. Interesting to note that on some stretches like from Carlsbad and Guadalupe Mountains to Big Bend I felt like maintaining 60mph was a chore and barely managed 6.5 mpg, continually downshifting to 3rd, whereas I was doing 75 in Illinois yesterday afternoon without any effort to stay in 4th gear and got closer to 7.5mpg. (Edit: ok more like 7 mpg @ 75 and 7.5 mpg @ 70).

I watched my transmission temp for much of the trip too. It seemed to sit around 201F most of the drive - about 5F warmer than last year. Not sure if that was due to the heavier trailer than before or to the new steel bumper and winch affecting the air flow. I did see the pan temp get up near 210F regularly when dropping into 3rd on long uphill highway passes, and as high as about 235F (with the TC pushing 250F) on one very long mountain pass in CO on my way to the LCDC. I may look into mounting a secondary transmission cooler in the spring (also doing a full transmission fluid flush again along with the diffs and transfer case since by spring I'll be at 90k).

I also weighed my rig on the way home yesterday afternoon. Wow.

Steer axle: 3460
Drive axle: 4620
Trailer axles: 5200

Measured GVW: 8080 (3460 + 4620)
Est GVW fully loaded towing: 8350 to 8400 (8080 + 200 + ~70 to 120)

Measured Gross: 13,280 (3460 + 4620 + 5200)
Est Gross: 13,550 to 13,600

Edit: My trailer TW is about 800#, so I'm pretty close tothe trailer GVWR of 6000# and without the trailer my drive axle is probably closer to 4000-4200# when otherwise loaded with kids and gear

That was with a 45-50 gallons of gray and black water, which sits over or behind the axle. I did not have a chance to weigh empty or unhitched - we'd been in the car 2.5 days at that point and I was already pushing 7pm to get home. My wife and middle kid weren't in the truck, so add 200# to the above, plus a mostly empty cooler and an empty rotopax and I can see the total weight of my rig approaching 8400#.

The good news is that I'm under the GCWR of 14,400. The bad news is that I'm well over the GVWR of 7,385 by 1000# when towing. While I have medium-duty rear springs (Tough Dog 240# coils), my fronts are still the 500# stock rating. The next time I do a suspension upgrade I will move to heavier fronts (675#) and rears (at least 340#, possibly more) - the truck towed and braked fine, but going over dips in the highway with the trailer in tow it was quite floaty - more like a Caddy than I'd like.

 

[Sandroad]

That's quite the rig!

 

[linuxgod]

That's quite the rig!

It's not nearly as built as some rigs around here even.

• winch+bumper = 200#
• sliders = 150#
• rack, shovel, etc = 120#
• tires/wheels = +120#
• Bag-o-recovery gear = 60-70#

Of course I already know the trailer TW is about 800#, so the actual weight when not towing (but still loaded with 3 kids and gear) is about 7600#.

 

[vapilotda]

Great intel. I'd imagine the bumper is causing a little bit of airflow change. I certainly didn't track a lot of weight numbers but when I rented the 25 foot Airstream in Carbondale and towed it almost 4 hours to Telluride, I achieved 13.5 mpg using premium fuel. I know the trailer is 800lbs of tongue and about 5800lbs dry. We, obviously had the back loaded with stuff and a little bit or fresh water and assorted items in the trailer.
On the flipside, I rented a 29' passport this past weekend and towed it to the mountains of VA with a good sized mountain to go over and temps almost 90 degrees. The weight stats were fairly similar to the Airstream. I got 8.5 mpg both ways on regular pump gas. With both tows, the pan and TQ like to sit about 197 on flattish ground. The highest I ever saw the pan was 212 (both trips) TQ peaked at 230 and the engine would top out at 201. The motor really is happy above 3000 rpm when towing uphill. The engine temps come up above 200 when I'm pulling uphill below 2700 rpm or so and if I take it down a gear, temps rapidly swing back below 200. Its been a big learning experience in towing with this truck.
I'd be curious of how much of the aerodynamics of the airstream played into my fuel economy.
I'll be doing the trans fluid swap this weekend as well. Thanks again @linuxgod for all of your input on this subject.

 

[linuxgod]

@vapilotda make sure you do the full 12 quart swap, not just the recommended 3 quart pan frail and fill. I don’t understand why Toyota would even recommend that.

Good to know on your experience. When I was stock (except for the rack) I used to get about 10mpg when towing, give or take 1 mpg depending on speed.

The airstream probably helps by 0.5 to 1 mpg I’d guess, depending on speed. I have a few skylight covers and two solar panels on my roof, none of which help aerodynamics I’m sure. Keep in mind I’m running heavy 34” tires as well, plus a bunch of crap on my roof rack. We got about 13.5 mpg without the trailer going from Chicago to Baltimore before I did the bumper (70-80mph the whole way). Best I ever saw without towing was 17mpg when stock. Next time I get a good highway trip in without the trailer I’ll update the group, but I suspect the bumper has a negligible impact on mileage for me now (probably 1/2 mpg or so) - the giant wall I’m pulling hurts a lot more, and the heavy tires really show a hit

 

[indycole]

Next time I get a good highway trip in without the trailer I’ll update the group, but I suspect the bumper has a negligible impact on mileage for me now (probably 1/2 mpg or so) - the giant wall I’m pulling hurts a lot more, and the heavy tires really show a hit

FWIW I haven't seen any dip in mileage from the bumper. I attribute most of my lost fuel economy to larger tires and drag on the roof.

 

[vapilotda]

@linuxgod The full flush is absolutely the plan. I swap the trans, axles, and xfer case every 30k. I know that's probably excessive but for my OCD self, it's peace of mind and a it doesn't cost much money. I was talking to Cody about going to 34s on mine over the trip it seems like that may be a sizable hit in mpg. Are you happy with the tire size and towing? I can still get 16 to 17mpg with the 285 70 17s on the truck now (unloaded of course.) ....
Not that I own this vehicle to be concerned with good gas mileage...haha

 

[linuxgod]

@linuxgod The full flush is absolutely the plan. I swap the trans, axles, and xfer case every 30k. I know that's probably excessive but for my OCD self, it's peace of mind and a it doesn't cost much money. I was talking to Cody about going to 34s on mine over the trip it seems like that may be a sizable hit in mpg. Are you happy with the tire size and towing? I can still get 16 to 17mpg with the 285 70 17s on the truck now (unloaded of course.) ....
Not that I own this vehicle to be concerned with good gas mileage...haha

I'm doing mine every 30k as well.

I don't think the jump from 33s to 34s will be a hit, but the Nittos are heavy (like 65# per tire) and very sticky. I attribute most of my mileage loss to the traction gained (and thus rolling resistance lost). Note that my mileage #s listed for this trip are adjusted, as my speedo is 5% slow (i.e. 60MPH is actually 63MPH per every radar sign I find)

 

[TeCKis300]

I'm doing mine every 30k as well.

I don't think the jump from 33s to 34s will be a hit, but the Nittos are heavy (like 65# per tire) and very sticky. I attribute most of my mileage loss to the traction gained (and thus rolling resistance lost). Note that my mileage #s listed for this trip are adjusted, as my speedo is 5% slow (i.e. 60MPH is actually 63MPH per every radar sign I find)

I think it's less the weight and stickiness, and moreso the the diameter (gearing) in your rig. My tires are actually 71 lbs, and probably more rolling resistance at 305 section width. Though less tall, so less gearing loss.

I believe gearing to be the likely cause of your motor running in the very rich (inefficient) part of the load table. This part of your observation really speaks to that.

Interesting to note that on some stretches like from Carlsbad and Guadalupe Mountains to Big Bend I felt like maintaining 60mph was a chore and barely managed 6.5 mpg, continually downshifting to 3rd, whereas I was doing 75 in Illinois yesterday afternoon without any effort to stay in 4th gear and got closer to 7.5mpg. (Edit: ok more like 7 mpg @ 75 and 7.5 mpg @ 70).

At lower loads, the engine can operate at stoichiometric (most efficient) air/fuel ratios of 14.7 parts air, to 1 part fuel. In relatively higher load regions, it starts enriching the fuel mixture to maintain combustion chamber temps and stability. It's a ratio gradient that goes all the way to 10/1 depending on load. So mpg goes down the tubes at higher loads. The engine naturally makes more power at higher rpms, and has deeper breathing (i.e. volumetric efficiency) capacity before getting into high load fueling regions. Which is why you are seeing better mpg as it's running in a more stoichiometric region of the fuel table, even though it's making more power to sustain the higher speeds.

Long winded way to say I really think you need some gears to bring the motor back into the efficient load regions of its operation. Your motor is literally swilling fuel to keep itself cool.

Side note to the LX570 guys that like to run lower octane towing heavy loads - your engine may resort to richer fuel mixtures to keep itself cool and safe if it senses knock when running lower grade fuel.

Here's what a notional A/F target table looks like. It may be a bit hard to digest for the uninitiated, but if you're curious:

 

[LC2018]

I tow our Winnebago 2451BHS (26’ 9”) with a dry weight of 4,880 lbs using a 2015 F150 XLT with Max Tow Package, e-brake controller and a WD hitch with anti-sway bar.

I do not intend to tow with our 2018 LC but feel comfortable knowing I can hook it up and move it around.