2013 KIA Soul, 2013 KIA Rio 5 Door
My wife and I traded in an '07 Kia Sedona and '09 Kia Sportage for something more fuel efficient. She got a 2013 Kia Soul and I got the Rio 5-door. I asked about the ECO. Dealer said it changes the gearing a bit to give a bit less power and shifts sooner. When you turn it off it gives you a bit more power. That's also what I've read here on the forum. I haven't been able to actually get out and test it myself as we've only had our cars a few days. Hope that helps. As far as oil changes, read this: Top 7 Urban Legends About Motor Oil - Edmunds.com I need to dig in my manual and see what it recommends because that's what I keep hearing, change it at the interval recommended in the manual and that it doesn't really matter whether using synthetic or conventional. I've been using synthetic in all my vehicles though and change it about every 6,000mi here in US or 6 mos, whichever comes first.