I own an Optra and i would suggest the Vios instead of the Chevy.
The chevy optras ride is nice and it is spacious but it really is a gas guzzler.
i could get around 8+km/l but thats with mixed city/highway and mostly no A/C.
average is around 7km/L.
Service and parts are more expensive, my last CASA tune up cost 8+K. and thats without any major parts replacments.