Why no KDSS in the TRD PRO?

[DeepSea]

I know this topic will cause some angst but I'm curious to know why Toyota did not opt to have KDSS in the TRD PRO because it is specially designed as a premium off-road feature. Check out this writeup and video by Australia 4x4 where they compare KDSS equipped/unequipped Land Cruiser Prados:

https://www.4x4australia.com.au/reviews/road-tests/1606/toyota-prado-kdss-test

Here are some excerpts:

With KDSS, one end of each sway bar is connected to the chassis via an hydraulic cylinder, rather than being directly attached to the chassis. These two cylinders, one at the front and one at the rear, are then connected via hydraulic lines that allow an exchange of hydraulic fluid between the two.

When the vehicle is cornering on-road and tries to lean over, the pressure from the front and rear cylinders is cancelled out, which doesn’t allow an exchange of fluid between the two. With the ends of the sway bars locked solid, the sway bars then have to twist – as they do in a conventional suspension – to suppress body roll.

In an off-road situation, where rough ground will have the wheels on one side of the vehicle travelling in opposite directions, fluid can flow between the two cylinders. This relaxes the sway bars for greater wheel travel. On the Prado’s rear axle, KDSS increases wheel travel from 465mm to 565mm (more than 20 per cent).

The other benefit of being able to relax the sway bar for off-road use is that a stiffer sway bar can be employed in the first place on the VX, which leads to flatter on-road handing.

SO, HOW well does it work? Surprisingly well, in fact. And while we have always been aware of the difference KDSS makes, it was illuminating to drive these two back to back.

Jumping from the GXL to the VX on-road, you could instantly feel the flatter handing, the shaper turn-in and the better body control. The VX is also noticeable smoother when entering corners and when transitioning from leaning over to an upright stance. The KDSS-equipped VX is a noticeably crisper and sportier on-road drive than the non-KDSS GXL. Some of the benefit here comes from the VX’s 18s, but the critical difference, namely the reduced sidewall height, is only in the order of eight per cent, so it’s not a significant amount.

Off-road, especially in broken and rough ground, the VX feels suppler and is certainly more capable with all the extra travel. In mud and sand, where travel isn’t so much the issue, the benefit lessens.

 

[Angelo]

I know this topic will cause some angst but I'm curious to know why Toyota did not opt to have KDSS in the TRD PRO because it is specially designed as a premium off-road feature.

I only have a couple of guesses. I agree that everything I've read as far as reviews about KDSS makes it seem like Toyota should've included it on every 4x4 they build. My guesses on why it's not on the TRDP trim would be...

- Cost. The KDSS system upcharges the already semi-premium TE / TRDOR trim. With the added cost of the Bilstein suspension and other trim add-ons already on the TRDP, maybe they thought they might be pricing it a bit too far out of range.

- User maintenance / Reliability in the field. Everything I've heard about the KDSS is that it takes a relatively specific knowledge base to repair. Granted I haven't heard of any rampant issues aside from the "KDSS lean" from a few users after their lifts (certainly nothing with regard to reliability)... and clearly the system is designed for mixed on- and off-road use, but strictly speaking it IS a hydraulic system that could get torn on a rock on the trail. Leaving it out might just be one less thing to break.

Just a couple of thoughts.

 

[RyanEJ25]

Why not get a trail with kdss and add Bilstein 6112/5160? Isn't that the same thing. I get the TRD badging won't be there but can be added if really needed.

I bet cost is a huge factor. I mean look at Toyota not offering Android auto or Apple carplay because they can keep all the profits their own OS.

 

[DeepSea]

I only have a couple of guesses. I agree that everything I've read as far as reviews about KDSS makes it seem like Toyota should've included it on every 4x4 they build. My guesses on why it's not on the TRDP trim would be...

- Cost. The KDSS system upcharges the already semi-premium TE / TRDOR trim. With the added cost of the Bilstein suspension and other trim add-ons already on the TRDP, maybe they thought they might be pricing it a bit too far out of range.

- User maintenance / Reliability in the field. Everything I've heard about the KDSS is that it takes a relatively specific knowledge base to repair. Granted I haven't heard of any rampant issues aside from the "KDSS lean" from a few users after their lifts (certainly nothing with regard to reliability)... and clearly the system is designed for mixed on- and off-road use, but strictly speaking it IS a hydraulic system that could get torn on a rock on the trail. Leaving it out might just be one less thing to break.

Just a couple of thoughts.

I agree and great points. I just wish the TRDP had the sunroof and JBL. Surprised it doesn't for how much it's hyped up and what they're charging for it.

 

[DeepSea]

Why not get a trail with kdss and add Bilstein 6112/5160? Isn't that the same thing. I get the TRD badging won't be there but can be added if really needed.

I bet cost is a huge factor. I mean look at Toyota not offering Android auto or Apple carplay because they can keep all the profits their own OS.

Yep my Trail has KDSS hence why I was wondering why the TRDP doesn't

 

[jpachard]

+1 on overpricing the pro.


Sent from my iPhone using Tapatalk

 

[wfo9]

Subject has been beat to death....

3 going theories on why they did not include it.

1. Strictly removed it to make more profit. The pro pulls a premium and by not including KDSS they can charge more with less investment in the base vehicle.

2. The Toyota engineers would not approve KDSS with the lift that TRD wanted to run and made them pull it. You have to realize the Pro is not made in the factory. It is optioned at the port for the US market. It's more like an aftermarket package added to a trail.

3. Since KDSS is a bit stiff at speed offroad. The TRD folks were targeting a desert type "do it all" offload rig . So they opted not to include KDSS due to the better mid speed performance of the traditional swaybar system off-road.


Having been around these trucks for a few years now in many different conditions... I would say #3 makes the most sense. KDSS can be harsh and it really limits the suspension ability to follow uneven terrain at speed. It does a great job on trails at low speeds as well as on paved roads at speed.....



Anyway.. Those are the 3 theories that have been discussed and argued on this forum many times over.

 

[Throwback]

I think wfo9 must be right with option 3. I've owned a TE with KDSS and now one without KDSS. If slow, high-articulation crawling is the main usage the KDSS is great, but if running rough roads over 12mph the non-KDSS is much better for soaking up bumps.

I like slow trail crawling, but I also like running forest service roads with washboard sections and my KDSS truck was brutal doing that.

My non-KDSS truck is great in that situation and the soft OEM suspension is one reason why I'm hesitant to lift it.

 

[wfo9]

I'll add a 4th theory, and I think it would also explain why they don't have it as an option for the pro.

The time it takes to install a lift with KDSS is increased... It would open up the process at the port to many potential mistakes (like the KDSS swaybar bolts stripping out). The time plus the added training and having to do it in different ways between vehicles would not be ideal. Perhaps they looked at the port labor time and decided it just made no sense. I'm sure they could have come up with tooling to make it easy... but there is just no easy way to deal with KDSS by hand. If you watch how an actual production shop works.. People can't be spending time struggling with something. It has to be relaxed and easy with 0 fatigue and easy movements.

 

[spizike9]

I think wfo9 must be right with option 3. I've owned a TE with KDSS and now one without KDSS. If slow, high-articulation crawling is the main usage the KDSS is great, but if running rough roads over 12mph the non-KDSS is much better for soaking up bumps.

I like slow trail crawling, but I also like running forest service roads with washboard sections and my KDSS truck was brutal doing that.

My non-KDSS truck is great in that situation and the soft OEM suspension is one reason why I'm hesitant to lift it.

Weird. I have KDSS on my Trail and it's like butter on fire roads. I do have Fox 2.5 with resi all the way around though.

 

[wfo9]

Weird. I have KDSS on my Trail and it's like butter on fire roads. I do have Fox 2.5 with resi all the way around though.

It is situational.. If the road is smooth with even bumps for each wheel... Then yes, the suspension can soak it up. However, if each wheel is going a different direction it is difficult for the rest of the suspension to completely makeup for the stiff (street tuned) sway-bar. A better suspension will help for sure though... It just feels much better with the standard or no swaybar at all. But below 12mph the KDSS is much better. It is give and take.. KDSS with OME (for example) at speed offroad.. is pretty bad. Throw on FOX, King.. and things get much improved.. But it can be better... No perfect answer for all scenarios.

But the Pro would be rougher at speed with KDSS. No doubt about that.

 

[b407driver]

I'll add a 4th theory, and I think it would also explain why they don't have it as an option for the pro.

The time it takes to install a lift with KDSS is increased... It would open up the process at the port to many potential mistakes (like the KDSS swaybar bolts stripping out). The time plus the added training and having to do it in different ways between vehicles would not be ideal. Perhaps they looked at the port labor time and decided it just made no sense. I'm sure they could have come up with tooling to make it easy... but there is just no easy way to deal with KDSS by hand. If you watch how an actual production shop works.. People can't be spending time struggling with something. It has to be relaxed and easy with 0 fatigue and easy movements.

THIS.

Especially in concert with your #1 above; it's all about numbers. The TRD Pro was made to sell trucks at a higher price. They sell every one they can make, as fast as they can make them; it didn't take a brain surgeon in the marketing department to figure out that they'd be pissing money away if they'd included KDSS in the TRD Pro.

The prototype TRD Pro with KDSS that we all first saw wasn't a mistake nor an abortion, it was the best all-around vehicle that they could reasonably make given the 5th Gen platform. That they changed the TRD Pro specs prior to production was simply marketing math.

 

[b407driver]

It is situational...

...But the Pro would be rougher at speed with KDSS. No doubt about that.

But would it be rougher than a KDSS-equipped Trail on stock suspension, that is the real question. For all we know, the TRD spring rates and dampening characteristics were designed with KDSS in mind. Trail shocks are identical to SR5 shocks; that's the part that makes little sense.

 

[wfo9]

But would it be rougher than a KDSS-equipped Trail on stock suspension, that is the real question. For all we know, the TRD spring rates and dampening characteristics were designed with KDSS in mind. Trail shocks are identical to SR5 shocks; that's the part that makes little sense.

KDSS is rougher at speed offroad. It's just physics. The sway-bar dynamically changes the spring rate across the axle. This is true of any sway-bar, but the KDSS sway-bar is tuned for road use and is pretty stiff (this is what allows it to corner flat). Take the swaybars off totally and the straight line handling for mid speed offroad is greatly improved. Put a KDSS swaybar on and it is greatly diminished. Put a std sway-bar on and it is diminished some. Ideally, you could tune the swaybar for specific conditions and yaw.. KDSS sort of does this, but it is pretty much just two modes. Below 12mph and above. Its' sweet spot is trails at below 12mph and road use at speed. This ends up being what most people want.

We will never know all the reasons they chose not to offer KDSS on the pro. It is clearly the best choice for some use cases but also clearly not the best choice for others. So, they picked a position and went with that. The only reason the initial prototypes had it was probably availability in the region it was being developed. West coast was all KDSS trails at the time....

I still don't quite buy into the pure profit play. It's probably a combination of things that we will never know. It would be fun to know the actual answer, but doubt we will ever find out.

 

[Vinsil]

Pro's are appearance packages for the US market.

The trucks/suvs are not top end models but commands top end pricing.


I believe it is a profit driven margin for the US consumer. Looks cool, rare, costs more....totally a US consumer in mind.

KDSS is performance driven and they offer it in the model most suited for modifications and the more enthusiast market.

Yes it is slow or fast with the use but really...it works for most situations and the active sway bars are pretty sweet. For the hardcore rock crawler, no. But the Runner is not ideal for that. For the desert racer, no. But the Runner is not ideal for that.

The sr5 fits the everyday use perfect. The trail fits the weekend warrior/off-roader perfect. The limited fits the tech and luxury person. The pro fits the non modding, different from other runners, sell in two years model.

This will piss off people but IMHO it feels right to me.

The difference for me was big, for our use. KDSS is awesome for daily use, works great at slow off-road stuff, and it isn't a problem for mods if you've done some things in the past. I understand people who are fearful of it but it wasn't anything bad to deal with doing my lift either.:argue:

 

[Throwback]

Having owned both, I can say very confidently that the non-KDSS truck rides very significantly smoother on rough dirt/gravel roads and on the highway.

My '14 non-KDSS is smoother on asphalt with C-Load KO2s at 44psi, than my '14 KDSS was on asphalt with P-metric Michelins at 32psi.

These discussions are always chock full of confirmation bias, but from a true utility standpoint the TRD Pro is more functional without KDSS as it is marketed to be a high-speed desert running type vehicle.

 

[b407driver]

These discussions are always chock full of confirmation bias, but from a true utility standpoint the TRD Pro is more functional without KDSS as it is marketed to be a high-speed desert running type vehicle.

They are indeed full of it. As we know. but that second part is primarily opinion/conjecture.

Marketing is just that: marketing. I'd bet even the most hard-core off-road enthusiast on this forum doesn't drive their vehicle more than 10% 'offroad'. Suggesting that the TRD Pro was designed primarily for high-speed desert running ignores the fact that all our vehicles are mostly on the road. While the shocks may have been tuned with high-speed desert running in mind, the vehicle is marketed as such, not designed as such.

The bottom line is that we'll probably never really know why the TRD Pro prototype had KDSS, and likely a slightly more robust lift, compared to the production model. KDSS certainly has its fans and detractors here, none of whom drove the prototype(s) nor were present during the decision-making.

 

[Jetboy]

It's cost cutting.

If cost wasn't an issue and you wanted the softer sway bar from the sr5 model being better for intermediate speeds - Toyota would just manufacture a softer sway bar for KDSS. Problem solved.

If you wanted a softer sway bar but only had the option of going to the existing parts bin - then the sr5 sway bar would be the alternative.

I do agree that mid-speed the stiff KDSS sway bar is jarring at times on rough terrain. On the spectrum of vehicle speeds KDSS is great at low speed and great at very high speed - both on and off road. It's not ideal at intermediate speeds of say 15-25mph. In that range the springs are doing a large portion of the work to absorb bumps and any bump on an individual tire is going to experience a significantly higher spring rate and result in more energy transferred to the body. At low speed KDSS opens and does it's obvious function - which is a lot more than just disconnecting a sway bar - it controls the body. At higher speeds the forces go up and the shocks become the primary resistance to motion - the heavy sway bar then is a positive thing again. But at intermediate speeds the stiff spring rate can make for an uncomfortable jarring ride.

On the highway - most bumps effect both tires on each axle simultaneously and the sway bar has no spring effect, so the bumps on the highway are basically a wash between KDSS and non-KDSS. It's the cornering on the highway where KDSS really shines IMO. For that it's night and day difference. It's even more pronounced when you add a load or weight on the roof rack.

I think it really depends on what you want to do. If you want to run 50+mph in the desert, I'll take KDSS without hesitation. If you want to run 25mph - I think non-KDSS would be the better option. For my use which is 95% highway - it wasn't a close call. KDSS was a must have.

It does surprise me a bit that Toyota doesn't spec a softer sway bar with KDSS for the TRD Pro. There's also no reason you can't have KDSS and a disconnect. It would probably be a lot easier than doing a disconnect on a non-KDSS sway bar.

 

[Ron4RNevada]

Y'all shoulda' bought an SR5 and been done with it - - -

 

[Leucifer]

I agree and great points. I just wish the TRDP had the sunroof and JBL. Surprised it doesn't for how much it's hyped up and what they're charging for it.

TRD Pro can be had with sunroof depending on market.
Canadians get the Pro with sunroof/moonroof (whatever you want to call it).