During last summer when gas prices went out of sight, I engaged the ECO (economy) setting on my 2013 Elantra GLS. It certainly did save me some gas, and I was happy with the performance.
Well, since then, gas prices have dropped somewhat and I can afford to turn the ECO off. Having done so, the Elantra is driving like it has a super 6 cylinder motor in it, whereas with the ECO system engaged, it felt more like a 4 cylinder engine.
I drive mostly in the city on short hauls and although I'm finding the gas economy is not as good, the smoothness and power from the engine more than makes up for the cost difference.
On saying that, if the cost of gas goes up to $1.36/litre (I live in Toronto), I will once again, use the ECO and live with the performance difference. Money = Power. What else is new?