For this test we wanted to collect models with a three-cylinder engine of about 120 hp in combination with a manual six-speed gearbox. At Toyota we thanked for the hybrid Yaris (with 116 hp and automatic transmission) and we chose the conventional Yaris 1.5.
Ford lent us the confusingly named Fiesta Hybrid, because it is ‘only’ a mild hybrid. The i20 and the Rio are also mild hybrids and with common designations such as ’48V’ and ‘MHEV’ there is no ambiguity about that. Are mild hybrids more economical than a regular Yaris in practice?
How does a mild hybrid work?
The technical affinity of the Hyundai i20 and the Kia Rio can be seen under the bonnet: both hatchbacks are powered by a 1.0-liter three-cylinder with a turbo, a starter generator and a 48-volt on-board network. The energy recovered during braking disappears in a miniscule 0.44 kWh battery pack. The starter generator can draw on this and give the combustion engine a boost from 5 to 13 hp.
In the i20 and Rio, the manual six-speed gearbox automatically goes into neutral when you release the accelerator pedal in eco mode. That way, the car rolls out without the friction of the gearbox, which is better for fuel consumption.
So (un) economical are mild hybrids
But as smart and plausible as this may sound, the Hyundai i20 and the Kia Rio consume more fuel than their competitors. Both complete our consumption test with an average consumption of 6.4 l/100 km or 1 in 15.6.
The Ford Fiesta Hybrid also has mild hybrid engineering and settles for just 5,7 liter per 100 kilometers. That equates to 1 in 17.5. That’s another way to do it! The Toyota Yaris 1.5 has no modern frills at all (not even a turbo) and shows its skills for it 5.8 l/100 km (1 in 17.2). The technicians at Hyundai and Kia will scratch themselves behind the ears.
Mild hybrid technology can ensure low consumption, as the Fiesta Hybrid shows, but does not guarantee economical kilometers. The Hyundai i20 1.0 T-GDI 48V and the Rio 1.0 T-GDI MHEV are the biggest slokops in this test. The Yaris 1.5 does justice to the Toyota image and is economical.
Curious about the full test from Auto Review 5/2021? Don’t feel like going outside? Order Auto Review 5 in our webshop.