Toyota moves to highlight the differences between a 'full' and 'mild' hybrid

Published on 8 January, 2020

There is a lot of confusion over the differences between a 'full' and a 'mild' hybrid.

Overview

We have heard a lot about 'hybrids' these past months as more car companies strive to have the word 'hybrid' associated with their models.

The problem is that there is a lot of confusion over the differences between a 'full' and a 'mild' hybrid.

Despite repeated explanations it appears people are still mixed up over the use of the word 'mild'.

And that has prompted Toyota - the country's biggest seller of 'full' hybrids - to help clarify the significant differences between the two set-ups.

It says people need to understand that a 'mild hybrid' is just a conventional petrol or diesel engine with a low-voltage (48v) battery and an electric motor to power the likes of air con, radio etc.

At low-engine speeds, the battery and motor can give the engine a small electric boost during acceleration.

But, it stresses that "unlike full hybrids, the electric motor cannot power the car on its own, and they cannot drive in zero-emissions mode".

Those are critical points.

A 'full hybrid', meanwhile, can drive on battery power alone for as much as 62pc of the time, studies have shown.

Toyota claims: "A mild hybrid cannot drive on pure battery alone and therefore delivers considerably fewer benefits than a full hybrid."

In a series of comparisons it points out that:

* Battery power in a full hybrid is up to 600 volts while that of a mild hybrid is limited to 48;

* It claims full-hybrid fuel consumption is 13pc better than a 'mild' model's;

* It claims its hybrids produce 12 times lower NOx emissions;

* And, it claims, 'mild' hybrids emit up to 30pc more CO2.

The Japanese giant also says its hybrids are all petrol with automatic transmissions, but that many 'mild' hybrids are diesel with manual transmission.

There is one other area in continuous need of clarification when it comes to hybrids.

I - not Toyota - am talking about 'plug-in' hybrids.

They differ from 'full' in that they have a larger battery pack (which can impinge on boot space sometimes) and can be charged at home or publicly.

The benefit is that you can potentially drive up to 50km or so on electric power only.

That can mean only having to use engine power in the course of longer journeys (and don't forget the normal benefits of full-hybrid driving still accrue).

Unlike a normal hybrid, however, you really need a home charging outlet.

Not to mention the discipline and commitment to plug-in regularly to benefit from the ability of the larger battery pack to store 50km-or-so worth of energy.