I'm getting ready to throw a trans cooler in my 08 JKU and I'm trying to figure out what trans fluid I need to get to top it off after I install the cooler. Only problem is I don't know if I have conventional or synthetic ATF +4 in the JK or not. I don't want to mix conventional with synthetic because I've heard it might not be good. Although I just read that ATF+4 is only a synthetic ATF. Can anyone confirm this? Thanks!