The stock 17" wheels on the Lancer GTA are already borderline in terms of comfort. But they have enough rubber on them that you won't damage them very much over potholes or when you accidentally scrape against a curb. 18" rubber requires thinner tires... and that will require great care and caution when driving down the street. Watch out for those killer potholes on EDSA... those square-edged drain covers at the C5-Kalayaan U-turn overpass... or those sharp-edged pits on Quirino Avenue... It's worse when it rains, because you won't see them coming...
Another issue is tires. The bigger your wheels, the more expensive the rubber. You have to factor that into your buying decision when getting the mags (50k is more than enough for 17" mags and rubber if you're getting ROTA and regular sports tires... it won't be enough for 18" mags and the same tires in the bigger size).
That said: 18" wheels look
fantastic on the Lancer. They should. They cost an arm and a leg.
