Why Toyota Is Building Vastly Different Vehicles On The Same Platform

“The Toyota 4Runner is the same as the Land Cruiser,” everyone is saying right now. “And it’s built on the same platform as the Tacoma, Tundra, Sequoia, and even Lexus GX!” It seems strange, which is why I chatted with the Tacoma’s chief engineer Sheldon Brown and asked all about this. What’s the deal with the TNGA-F platform underpinning vehicles that once had completely different platforms? Here’s what he told me.

I covered some of this in my thorough Toyota Land Cruiser review, but much of it’s new. And given how much folks are talking about how similar the Land Cruiser is to the 4Runner, it’s worth digging into why Toyota says it decided to build five machines — some of which were very different — on the same bones.

Take a look at the photos above and below, and you’ll see the machines I’m talking about — five vehicles from Toyota with the same general frame and suspension architecture, and three with the same engine and transmission. It’s remarkable, especially when you consider what the vehicles looked like just a few years ago.

The Tundra and Sequoia — built on the related XK50 and XK60 platforms — had a 5.7-liter V8 hooked to a six-speed automatic, with the former lasting from 2007 to 2021 and the latter starting in 2008 and getting its TNGA-F update in 2023.

The two old platforms had a similar independent front suspension, though the Sequoia ditched the Tundra’s leaf-sprung solid axle for coil-sprung independent suspension. Then there was the Land Cruiser, an $80,000 machine built on the “J200 “platform between 2008 and 2021:

The XK60 Sequoia and XK50 Tundra shared quite a few architectural bits, and while the Land Cruiser also shared powertrain and architectural elements with those two, it was also different in many ways. All three shared very little with the smaller Tacoma and 4Runner:

The 4Runner was around from 2010 until 2024 — an absurdly long run for that 1GR-FE 4.0-liter V6 mated to a five-speed auto. The second-gen Tacoma sat on a significantly different frame (though with similar suspension components), and shared the 4Runner’s powertrain before it got a refresh for the 2016 model year, when it got a new 3.5-liter V6 and some minor architecture changes.

The outgoing Tacoma was significantly different than the outgoing 4Runner, but now things have changed.

 

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Now we have a 4Runner, Tacoma, and Land Cruiser with the same engine/transmission, plus a Tundra and Sequoia that shares those vehicles’ frame and basic suspension architecture. Yes, whereas before there was quite a difference between the 4Runner, Sequoia, Tundra, Land Cruiser, and Tacoma, now they’re all built on the same bones, with three sharing a heart.

So what happened? How did Toyota blast out five all-new models so quickly and on the same platform? I asked Toyota to learn more:

The clip above, wherein I chat with the 4Runner and Tacoma’s marketing manager, doesn’t give a ton of technical insight into the extremely versatile TNGA-F platform, but it does discuss Toyota’s expected volumes.

The company believes there’s room in the mid-size space for both the 4Runner and Land Cruiser, which are about the same size. The Land Cruiser is expected to sell in lower volumes than the 4Runner, which is expected to sell in lower volumes than the king of midsize trucks, the Taco.

But let’s get to the main question people are asking: Why would you even buy a new Land Cruiser? “There is some brand loyalty,” Tacoma chief engineer Sheldon Brown told me, saying folks love the Land Cruiser brand. Plus, the mid-size segment is huge, with another Toyota rep saying there’s plenty of room for two offerings and that the company “[doesn’t] see cannibalization, per se.”

The Land Cruiser is meant to be more refined, offering unique styling to a different, perhaps older customer than the 4Runner. And that’s pretty much it: It’s the squared-off styling, it’s the Land Cruiser name, and it’s not a whole lot else that the Land Cruiser has over its sibling.

Check out all the underbody photos of the new Land Cruiser that I took and then see all the 4Runner underbody shots that I snapped, and you’ll see just how similar the two are.

Why Toyota Built One Platform To Rule Them All

I chatted with Tacoma Chief Engineer Sheldon Brown to figure out how and why Toyota build so many once-different vehicles onto a single platform, and he told me that, a few years ago, Toyota found itself facing a dilemma. The company was wondering if, in the face of increasingly stringent emissions standards, there was a place — long term — for body-on-frame vehicles.

It was, as Brown put it to me during an interview, “an existential crisis [for] the company” as pressure mounted to meet global Corporate Average Fuel Economy requirements (CAFE, as it’s called stateside). “We had to make sure we [developed our body-on-frame vehicles] in a way that was smart,” he told me, with a focus on minimizing total investment, which the company could need for electrification during these rather uncertain times where emissions policies are rapidly changing. “If we’re going to make this work, we need to make this as efficient as possible,” he told me about Toyota’s body-on-frame strategy.

“Every time we redid a platform, you really need to look at the life of that platform,” he said, noting how long the last-gen vehicles stuck around (the 4Runner, Tundra, and Sequoia were around for ~15 years, and the Taco was around since 2016 but those bones were fairly old). Those platform investments clearly paid off, but these days, it’s unclear what political or technical changes might necessitate a shift towards EVs, and so to mitigate risk, Toyota built One Platform To Rule Them All.

The result was the TNGA-F platform to underpin the five Toyotas you see above — the Sequoia, Tacoma, 4Runner, Tundra, and Land Cruiser, as well as the Lexus GX. This might have you thinking: How can you use one frame for vehicles that have such different requirements and that are so different in size?

How Toyota Built One Platform To Rule Them All

Well, one of Toyota’s answers to the first part of that question involves the uses of different frame thicknesses and metal strengths in different areas depending upon the vehicle load requirements (you can see different steel thicknesses in the image above).

Toyota calls the concept “islands of strength,” as I described in my Tacoma review:

“When we built that, we wanted to make sure the platform was adjustable,” Chief engineer Sheldon Brown told me. “The frame pitch as well as the frame silhouette stays for all intents and purposes the same,” he continued, referring to the width and side profile of the frame. But this didn’t mean the frame had to be overbuilt for smaller trucks that don’t need the same load-carrying capacity as bigger trucks.

“We can use an optimal gauge and material for areas where we don’t have quite as much requirement for strength,” he told me in reference to Toyota’s “Dejima” practice, named after an island off the coast of Nagasaki. The “islands,” in the context of the new Tacoma’s frame, are localized sections of high-strength or high-gauge (i.e. thickness) steel meant to bolster high-stress regions like where transmission/transfer case crossmember mounts or the rear of the frame near where a tow-hitch fastens.

In essence, the Tacoma’s frame is a patchwork quilt of various steels meant to optimize the frame for both strength and weight reduction. In reference to different gauges and materials such as 480 and 780 (that’s the tensile strength of the steel in Megapascals), Brown told me: “We laser-weld those together [in a flat piece], and then we form it, and then we bring those C-channels together to make this full box.” The result is weight savings and also anti-corrosion. Wait, anti-corrosion?

Brown showed me how the current frame adds stiffness to certain areas — there’s a gusset/overlapping panel that is arc-welded into place:

As you might imagine, the overlapping metals in the method above could compromise corrosion resistance, not just by allowing moisture to be trapped between the layers, but by reducing the effectiveness of the E-Coat anti-corrosion application process.

Anyway, I’m obviously not an expert on this, but you can read all about Toyota’s new TNGA-F frame in the presentation titled “Non-Linear Tailor Welded Blanks Application in Chassis Frame.” Here you can see how it compares to the old method of localized frame stiffening:

Here’s a look at parts of the frame that Toyota focuses on:

And this plot, if I have it right, actually shows typical stresses found on different parts of the frame. (Note, this presentation doesn’t apply specifically to the Toyota, and rather presents the general process):

The point is to allow a single frame to function for a multitude of use cases without adding too much unnecessary weight to vehicles that don’t have as high demands. As you might imagine, a 4Runner frame doesn’t have to be as strong as a Tundra frame, as the latter is designed to tow and haul significantly heavier loads.

So the frame pitches (i.e. width) stays the same across vehicles, but material thickness and strength can be adjusted, as can wheelbase. The wheelbase adjustment happens at the center of the frame, between the suspension “kick ups” at the front and rear, which are both optimized to handle the suspension loads that enter the frame in those areas. The front, especially, is optimized to handle crash loads, which is why Toyota is keen to keep these “kick up” regions common between vehicle types, adjusting just the center part of the rails:

So now that we’ve discussed adjusting both strength and length for different frame applications, what about width? While Brown and I didn’t dive deep into this topic, he did point out that that brackets meant to communicate side-loads (in the event of a side-impact) from the body into the frame have to be adjusted based on the distance from the rocker panel to the frame rail (which is larger for the mid-size trucks than it is for the full-sizers).

I snapped a photo of the brackets on the Tundra and Tacoma; here’s a look at the full-size truck:

And here’s the mid-sizer:

I’ll admit it’s a bit hard to tell the differences in the lengths of those brackets or the distance between the rail and the rockers, but apparently it’s significantly different between the vehicles.

What about compromises?

Well, chief engineer Sheldon Brown admitted that, even though Tailor Welded Blanking helps optimize the frame for different applications, using one platform for vastly different applications does come with some compromises. That’s just how engineering works — it’s basically a game of compromises.

An example of a compromise, he told me, is weight. The fact is that building a mid-size truck on a common frame with a full-size truck means the crossmembers are going to be longer than they need to be, and that adds weight.

“If we had to say what is the perfect size frame pitch, it would probably be narrower,” Shelded admitted about the new Tacoma.

He also mentioned that using a single frame design and modifying it via Trailor Welded Blanking is expensive, and not just as a result of using high-strength steel to bolster the vehicles that see higher loads — the process itself is more expensive.

In our discussion about compromises, Brown also mentioned the common knuckle design between all trucks, and alluded to the challenge of balancing the Tundra’s focus more on towing stability with the Tacoma’s focus on handling. He mentioned that the Tacoma had to have its sway bar moved back behind the chassis to avoid stackup of too many parts during a crash, though I wasn’t entirely clear on exactly which compromises were being made.

It’s admittedly a tough question to ask a chief engineer at a press drive: “Tell me how your vehicle is worse than it could be.” But hey, that’s how engineering works! Engineering is the art of compromise.

I Will Say: The Vehicles DO Look Good

It’s clear why Toyota decided to build so many vehicles on TNGA-F: To save money, especially during a politically uncertain time. And it’s clear how they did it: They adjusted the wheelbases at the center of the frame; they pushed the bodies out by bolstering them with brackets that tie side-loads into the frame in the case of a crash; and they adjusted the strength of the frame by welding in thicker and stronger metal in certain areas that see high loads in certain applications (like towing with the Tundra).

The compromises associated with platform sharing between these particular vehicles aren’t 100% clear to me, and perhaps they’ll become clearer as time marches on, but all the TNGA-F vehicles seem legitimately compelling. Some of them are so similar technically that it seems Toyota is trying to split a pie into too many pieces (the 4Runner and Land Cruiser come to mind), but will the average person really care that their car is basically the same as another under the skin? I’m not sure they will.