I have a 2001 XG with 62,000 km on it. Great car but the semi-synthetic tranny fluid turned dark when driving fast all day through Montana back on a VERY hot August day. Tranny works fine, & I did a fluid change in the drive way, (hindsight -should have had a power flush done), but the fluid still appears quite dark, although does not have a burned smell at all. Any thoughts? BC in BC