Well, I'm assuming this Jeep wasn't cared for at all - under the hood. The exterior and interior look great - like new as a matter of fact, but it's under the hood that was neglected. I don't have any service records. I was told that the oil was changed twice yearly, and that the fuel pump had recently been changed. This is a 2.5L 4 cyl. , and I am running 10w-30 valvolene oil. I have done no tests yet, I'm in the process of looking for a good mechanic.