Just bought a 1996 Rialta from my sister...her husband died and she has dystonia and drives very little. They bought the Rialta used with a dead transmission, automatic. He found a 1995 Eurovan with 5 speed trans and made a switch. I drove it for the first time today, liked it, and drove it home from SC to SW Virginia near Whitetop. Most of the way, it drove flawlessly. A few times, the check engine light came on and it would miss a little and lose some power...anyone have any thoughts about cause or how to pursue a remedy. Also, I have read questions about the different size tires on this Rialta...thoughts about putting the same size all around? I was impressed with the 2.5 L engine. Milage on it around 115,000. Any thoughts about switching engine oil to a synthetic, say Mobil 1? Any comments would be appreciated.