My wife and I have just bought a 2nd-hand 2005 Optra 4-door sedan LS from a local dealer. The gas consumption is much higher than our previous car (a Geo) but that was most certainly to be expected. We're finding it'll do about 500-550km to a tank, with each fill taking 50ish litres.
It's got a fair amount of power, but I'm finding I'd rather have the manual transmission. A 5-speed would help gas mileage too.
Within a month of buying the Optra LS we've brought it back to the shop for a 'check-engine' light. The Catalytic Converter was replaced along with a sensor. We'll see if this turns out to be a re-occurring problem or not. The repair was covered under the bumper-to-bumper.
Overall a good car so far, and worth purchasing if you can find one coming off a short term lease like we did.
My Chevrolet Epica which is pretty much just a larger edition of the Optra had problems with the "Check-Engine" light as well. I took it to the Dealership, and they said this is something to do with the Gas Cap. The light stayed on until we got filled up again, then it went off. Another cause for this could be Dirty Gas, so if it happens again to me, I am going to try a different Gas Station.
I bought a used Chevrolet Optra 2004. It was sold to me as very economic car in gas; the dealer said it would make 43 miles per gallon in a "perfect conditions" (No A/C in use, only highway miles, closed windows etc). After 2 months of using this car it become in nightmare; it only does 24 miles per gallon in a perfect conditions. This car is a fraud; I complain with BBB and they did nothing to help me, I paid $14.600.00 and I tried to re-negotiate with the the dealer and they only offered $6.000.00 to take it back 3 months after my purchase.
My message to you; keep away from this good looking, but a lemon car.