LX570 Towing - Why Did it Change from 8,500 to 7,000???

[scottcb]

Migrating over from the 60 forum as I'm looking at the LX570 - I need the towing capacity of the 5.7, but don't want a Tundra and the Lexus versions appear a lot cheaper, more vehicles for sale with less miles. I found this site (Lexus LX 570 Towing Capacity Table - 2009-2018 - Axle Advisor) which shows the towing capacity at 8,500 for early models and then 7,000 starting in 2011. That seemed really odd since I believe it is the same motor so I looked in the Lexus manuals which seems to confirm that. Anyone know why that would be? Would love some feedback from anyone who has towed with the LX570.

 

[TeCKis300]

Because SAE J2807

A standards based methodology was voluntarily adopted by manufacturers around 2011, Lexus and Toyota being among the first, which caused many models to receive revised ratings. This allowed an apples to apples comparison between manufacturers based on SAE standard performance criteria.

A hallmark of SAE required that tow ratings can no longer be based on stripped base-model vehicle with a single driver. Vehicles must be representatively fitted according to typical configurations. On a heavily optioned vehicle like the LX, would take a hit.

That said, I tow regularly at and above that limit. I also exceed GVWR with 6 passengers while towing. Exceedingly stable and capable.

The LX can also be modified to handle more weight still. With LT type tires. And augmenting the suspension - LX570 Augmenting for Load

 

[Markuson]

Migrating over from the 60 forum as I'm looking at the LX570 - I need the towing capacity of the 5.7, but don't want a Tundra and the Lexus versions appear a lot cheaper, more vehicles for sale with less miles. I found this site (Lexus LX 570 Towing Capacity Table - 2009-2018 - Axle Advisor) which shows the towing capacity at 8,500 for early models and then 7,000 starting in 2011. That seemed really odd since I believe it is the same motor so I looked in the Lexus manuals which seems to confirm that. Anyone know why that would be? Would love some feedback from anyone who has towed with the LX570.

Perhaps the more interesting question is...

Why does the Land Cruiser RETAIN its tow rating to this day...(I just checked)... while the LX’s tow rating dropped like that...?

 

[rscoleman]

Just a guess but rear suspension height adjustment and electronic controlled shocks compared to fixed spring and fixed shock is difference between LX and LC tow rating. Electronics on LX get down grade on tow weight due to complexity of configuring the electronics to deal with added weight.
Just a guess.

 

[TeCKis300]

Just a guess but rear suspension height adjustment and electronic controlled shocks compared to fixed spring and fixed shock is difference between LX and LC tow rating. Electronics on LX get down grade on tow weight due to complexity of configuring the electronics to deal with added weight.
Just a guess.

Negative. AHC is well up to the task and has proven to be an asset for those of us that tow really heavy. Where it does not help is that the system adds weight to the overall vehicle. That added weight, along with the many more upgrades as fitted to the LX (vs LC), is the core reason why the LX gets downgraded significantly. Not that the LC is a base model in any sense, but the LX has upwards of 300-400lbs more worth of accouterments, which subtracts from the chassis rated load capacities.

As I said earlier, SAE J2807 testing requires a representatively configured weight vehicle for the test. Previously, manufacturers used internal methodologies. Many of which based numbers on stripper chassis, and did not honor the highly optioned vehicles true weight.

An example that may help understanding is the Tundra. Within the 5.7L motor range, towing capacity spans 10,200 to 8800 lbs. A closer example might be comparing the same bodystyle, but SR5 to a well optioned 1794 Edition:
SR5 4x4 CrewMax 5.7L - tow capacity 9800lbs
1794 Edition 4x4 Crewmax 5.7 - tow capacity 8800lbs

SAE J2807 more greatly impacts vehicle configurations with higher weights:

TL;DR more highly optioned vehicles based on the same chassis will have less towing capacity.

 

[DirtNap]

Lexus is only in the US. So they had to use the weight of the average American -- times four passengers, it really adds up. The LC is global, so the impact of us 'Mercans on the *ahem* weighted average is much less.

 

[AFdude]

Lexus is only in the US. So they had to use the weight of the average American -- times four passengers, it really adds up. The LC is global, so the impact of us 'Mercans on the *ahem* weighted average is much less.

Lexus IS worldwide.

 

[bloc]

Lol, great answer. However, I do concur. Americans are generally some fat lazy people. I can say that, I am one myself. I sat next to an overweight person on a plane a few weeks ago. Pigged out on an entire sandwich and chips, and happily ate whatever flight attendant brought for snacks/cookies. These are the same people that claim to have gland/hormone/age related weight problems. It is a disgusting display of apathetic failure to accept responsibility of one's own health, and I think the current trendy body positive movement is bulls***. I could go on about impact on health care, medical insurance, eating more than one's share/food supply resource demand, etc. But to be safe, I'll end my rant here.

Great answer.

You do realize this is a forum for 200-series landcruiser "tech", don't you?

 

[Hammeredsole]

Great answer.

You do realize this is a forum for 200-series landcruiser "tech", don't you?

Yea, I do. I started ranting, my apologies

 

[RyanR]

I've towed at and above the rated GVWR and the LX really is a great tow vehicle for its wheelbase ie not a truck. I've put 2,200+ lbs in the back and the rear was sitting on the bump stops. Closed the rear hatch and AHC had no issue leveling out the truck and drove amazingly well considering I was carrying an early 90's Honda Civic worth of weight in the cargo area.

 

[JeffH]

A few questions I hope you all can answer.
i have a 2010 and SAE testing aside is tongue weight considered generally 10% of trailer weight? Is AHC able to handle 700 lbs tongue weight For a 7000 lb trailer? Also I live in the Rockies and with my 2200 lb camper now I use the engine braking of the vehicle as much as I can along with trailer brakes as needed. Does the extra weight of a 7000 lb trailer put a lot more stress on the engine using engine braking or should I just plan to use brakes more (understand I would be towing in 4th gear max). Looking at a larger camper - dual axle Lance 2375. One more thing I assume a WD antisway setup is a must have?

thanks

 

[TeCKis300]

Tongue weight is targeted to be 10-15% trailer weight. It's not always advisable to shoot for the lower end of that depending on other stability factors of the trailer, i.e. more tongue weight may actually help stability.

AHC is well up to the task of 700lbs of tongue weight. I recently sensor lifted my AHC and have yet to reset my WD bars for more tension to move more weight back to the front axle and trailer axles. You can see that I'm roughly at ~1150lbs tongue in this weigh in, for my ~7900lb travel trailer. 1500mile trip at 2000lb payload (between occupants, gear, and tongue weight) and no sagging no problemo.

I travel the mountains often. You want to use engine braking like it's going out of style. Even if that means having the engine rev up high in the band, where the most engine braking will be had. It won't stress the motor as it's far less stress than making power up hills. Save the brakes as much as possible on long downhills. Still use them, braking in a straight line before corners to stabilize the rig and make sure trailer is not pushing on the tow vehicle to much. Or when you need to scrub speed faster.

Yes, absolutely always use WD when towing travel trailers. It should not be looked upon as a crutch and would be bad form not to use one, and need one when that emergency maneuver or gust of wind happens.

 

[skrypj]

Sorry to necrothread, but I still have not seen a good explanation as to why the rating dropped.

Its not payload, the LX has enough Payload capacity to comply with SAE J2807. You only need 300lbs for passengers, 75 lbs for the weight distribution hitch(if required) and then 10% tongue weight. For 8500 lbs that is only 1225 lbs and the payload on my 2018 3 row, with I believe every package available, has a door sticker showing 1285 lbs.

So what else is there that could possibly limit the tow capacity? Maybe the rear axle rating? 4300 lbs seems like it would be plenty to support 10% tongue on a 8500 lbs trailer. I cant imagine the rear axle is much over 3000 lbs.

 

[Nothinghead]

Sorry to necrothread, but I still have not seen a good explanation as to why the rating dropped.

Its not payload, the LX has enough Payload capacity to comply with SAE J2807. You only need 300lbs for passengers, 75 lbs for the weight distribution hitch(if required) and then 10% tongue weight. For 8500 lbs that is only 1225 lbs and the payload on my 2018 3 row, with I believe every package available, has a door sticker showing 1285 lbs.

So what else is there that could possibly limit the tow capacity? Maybe the rear axle rating? 4300 lbs seems like it would be plenty to support 10% tongue on a 8500 lbs trailer. I cant imagine the rear axle is much over 3000 lbs.

Does part of the testing include actually testing the vehicle as a whole? I haven’t read SAE J2807. Did they take an LX off the dealer lot and actually put it through contolled tests with crappy soft OE tires? Do the 21” rims and lower profile tires cause it to understeer more when loaded up such that the gross combined weight rating is lower? Crappy tires and a few hundred extra pounds in the LX might make a difference. Having a heavier tow vehicle for a given GCWR cuts into what you’re left able to tow. Obviously, testing standards are meant to be more than just simple math of HP, wheelbase, brake size, weight and axle rating.

Maybe Mr T said 700 tongue weight rating for AHC (since Mr T is very conservative to maximize longevity and reliability) and so the eaters just said “10x tongue weight” and walked away.

Maybe it’s something dumber like the fact the LX has a lighter duty sway bar.

Thank you for listening to further speculation without answers.

 

[rscoleman]

I am speculating and speculating only however I think this might be why it went lower.
I think the GCWR is lower on Lexus vs LC models. So calculations based on GCWR result in lower rating.
My second guess would be sway control due to our short wheel base. However, this should impact both Lexus and LC.
My third guess would be braking performance of the truck-and-trailer combination at its maximum GCWR. Combos with a maximum tow rating of more than 3,000 pounds are required to stop completely from 20 mph in 80 feet or less. Less likely Lexus vs LC unless tire/rim size plays into this.
FYI best layman article I have found on new standards. https://www.motortrend.com/how-to/1502-sae-j2807-tow-tests-the-standard/

 

[LX Cruiser]

Does part of the testing include actually testing the vehicle as a whole? I haven’t read SAE J2807. Did they take an LX off the dealer lot and actually put it through contolled tests with crappy soft OE tires?

I looked hard for evidence they actually tested the LX but could not find it. My strong suspicion is they test base models and then simply subtract capability from the upper trim levels using the added weight of options as 10% of what they determined the base model could tow.

Very roughly, if the LX has 150 lb of extra weight due to the AHC, then that is 150 lb less tongue weight it can handle, so it can tow 1500 lb less, assuming tongue weight is 10% of trailer weight.

My guess is, they tested very few actual models, then applied math like this.

 

[skrypj]

I looked hard for evidence they actually tested the LX but could not find it. My strong suspicion is they test base models and then simply subtract capability from the upper trim levels using the added weight of options as 10% of what they determined the base model could tow.

Very roughly, if the LX has 150 lb of extra weight due to the AHC, then that is 150 lb less tongue weight it can handle, so it can tow 1500 lb less, assuming tongue weight is 10% of trailer weight.

My guess is, they tested very few actual models, then applied math like this.

That is the most reasonable explanation I have heard, tbh.

My ONLY other thought I had would be is if there is some requirement within the J2807 standard that says the truck has to be able to control the trailer in the event of the AHC system failing while towing.

 

[skrypj]

Does part of the testing include actually testing the vehicle as a whole? I haven’t read SAE J2807. Did they take an LX off the dealer lot and actually put it through contolled tests with crappy soft OE tires? Do the 21” rims and lower profile tires cause it to understeer more when loaded up such that the gross combined weight rating is lower? Crappy tires and a few hundred extra pounds in the LX might make a difference. Having a heavier tow vehicle for a given GCWR cuts into what you’re left able to tow. Obviously, testing standards are meant to be more than just simple math of HP, wheelbase, brake size, weight and axle rating.

Maybe Mr T said 700 tongue weight rating for AHC (since Mr T is very conservative to maximize longevity and reliability) and so the eaters just said “10x tongue weight” and walked away.

Maybe it’s something dumber like the fact the LX has a lighter duty sway bar.

Thank you for listening to further speculation without answers.

The only reason I find the wheel size thing hard to believe is that Ford actually required that you have the 20" wheels(vs the 17's or 18's) on the 2018+ F150 to get the highest GCWR. A lot of people didnt realize that. You had to spec the max tow package, but the max tow package didn't automatically force 20" wheels, you had to select those independently. If you did not select the 20's, you were stuck with the old pre-2018 GCWR.

It also caused the F150's with the heavy duty payload package, which put payload north of 2500 lbs, down at the lower GCWR as well because they only came with 17's or 18's. So even though they had a beefier frame, axles, springs, shocks, wheels, tires, etc, they still got a lower GCW rating.

 

[linuxgod]

This question came up in another thread a while back, and similar to the 150# answer above the answer was that the weight of an LX is more than an LC, so using the % tongue weight rule translates to the difference in total trailer weight.

 

[GordJ]

Is it possible that the engineers use a wheelbase, spring rate, vehicle weight, hitch location and frame spec formula and one or more of the parameters changed? Of course I am only guessing at what they input to come up with their numbers.