The launch of the Chevrolet Onix is one of the most significant in Brazil this year.

It is a true successor to the Celta as the brand’s flagship, although that predecessor remains in production for the forseeable future, even after 2014, when it will be fitted with ABS and airbags mandatory from that year.

Compared to the new Hyundai HB20 and Toyota Etios, obvious rivals, the Onix does not look any better than the Hyundai but its lines are attractive enough. It is not more aerodynamic (Cd 0.35) but is tops for cabin roominess thanks to a longer wheelbase (2.52m/99.2in) and width (1.70m/66.9in).

The automaker forecasts average sales of 12,000 units monthly for 2013, some 40% more than the veteran Celta, on sale for 12 years with only minor changes. The Prisma, the saloon version, is no longer produced in Gravataí, state of Rio Grande do Sul and will be replaced by an Onix equivalent early in 2013.

Derived from GM’s world Global Small Vehicles (GSV) platform, the Onix is 3cm/1.2in narrower and 11cm/4.3in shorter than the Sonic hatchback. Yet it did not inherit its telescopic steering column.

The model is manufactured at GM’s Gravataí plant in South Brazil. The instrument cluster is pleasantly simple and interior finish is good.

The seven-inch touch screen system MyLink (optional for R$1,200/US$600 on some versions) does not come with GPS yet can access the navigation app BringGo from a smartphone for R$100/US$50. 

The Onix is competitively priced from R$29,990.00/US$15,000 (1l/61cu in) with ABS and airbags to R$41,990.00/US$21,000 (1.4 litre/85.4cu in). A six-speed automatic transmission, exclusive among compacts, is due to arrive in six months.

One of the surprises the engineers achieved was the one-litre engine that delivers nothing short of 79 bhp (on ethanol), despite having only two valves a cylinder and a single overhead camshaft. That’s the same power as the HB20’s double overhead phased camshaft and multivalves though that has 4% more torque. 

The larger, 1.4-litre/85.4 cu in 104.5bhp engine delivers more power and the same torque as the also more elaborate, larger 1.5-litre Etios engine.

GM said the engines are 6% more fuel efficient compared to predecessors.