Why the 2023 Toyota Innova made the switch -- ladder frame vs. unibody chassis

The launch of the 2023 Toyota Innova in Indonesia last November 2022 was one of the hottest stories on our website.

And for good reason – the old Innova remains one of Toyota Motor Philippines’ best-selling models as it combines the toughness of a pick-up with the size and practicality of a seven-seat multi-purpose vehicle (MPV).

That’s because, underneath, the previous-generation Innova shares the same rear-wheel-drive, ladder-frame platform, and engines as the Toyota Hilux pick-up and the Toyota Fortuner sport-utility vehicle (SUV).

But many people were shocked when the 2023 Toyota Innova ditched Toyota’s venerable turbodiesel for a gasoline-hybrid powertrain, which necessitated the switch to a front-wheel-drive, unibody chassis.

What’s the difference between a ladder frame and a unibody? And how would this affect the all-new Innova’s driving characteristics?

You Might Like This: From electric tailgate to hybrid power -- here's what's new with the all-new Toyota Innova

A frame as old as time

A ladder frame is very simple – get two, massive steel girders linked by crossbeams for a ladder-like appearance, then put the bodyshell on top.

This design dates back to the advent of the automobile in the late-1800s and remains in use today, largely for pick-ups, SUVs, trucks and commercial vehicles. 

The outgoing Toyota Innova, Fortuner, and Hilux all share the same Toyota Innovative International Multi-purpose Vehicle or IMV ladder frame platform.

Advantages of a ladder frame include:

• Low production costs

• Easy to repair, especially when dealing with body or frame damage

• Extremely tough, especially in severe off-road conditions

• High torsional rigidity, which means the frame can withstand high-strain motoring like towing and hauling

• Easy to adapt for special purposes like hearses and strech limousines

Improved refinement and safety

On the face of it, having a ladder frame seems to make a lot of sense in the Innova.

But because Toyota wanted to integrate hybrid technology and more safety features, the Japanese carmaker had to radically rethink the Innova’s design, so they turned to unibody construction.

The Toyota New Generation Architecture (TNGA) is a modular unibody platform used by a variety of Toyota and Lexus models. The GA-C version of TNGA is dedicated to compact cars such as the Corolla, Yaris, Prius and Lexus UX.

A unibody combines the bodyshell and the frame into a single unit. The vast majority of passenger cars, starting around the 1960s, moved to this type of frame.

Advantages of a unibody include:

• Lighter design, which generally results in better fuel economy

• Smoother ride and handling because the body and frame don’t move around separately

• A lower floor, which results in a roomier cabin and additional space for things like a battery pack

• Better safety because the unibody can be engineered to absorb crash forces more effectively

More car-like Innova

In comparing a ladder frame and a unibody, one is not necessarily better than the other.

It’s always down to what a carmaker is going for in a new model, along with what a car owner will do with a vehicle.

When you need a tough car that can regularly haul heavy loads, ferry close-in security guards, or go through inhospitable terrain with hardly a worry about road conditions, a ladder-frame pick-up or SUV is definitely the more sensible option.

But if all you haul are kids and groceries, and the toughest thing in your commute is a few speed bumps, then a unibody sedan or MPV is much more comfortable.

As a result, the 2023 Toyota Innova will likely be more spacious and have better on-road manners than the previous model. 

And in case you haven’t read our comparison, the new Innova hybrid is also more powerful than the old Innova turbodiesel.

Which would you go for? A ladder frame or a unibody Innova?