Dan - As you know I've got the Zetec Turbo in mine, only running 230bhp or so though. On the drive down to Trax last summer it was probably close on 30 degrees outside, and I ended up "cruising" with a Skyline at ***mph for about 10 minutes, and my oil temp was closing in on 300 Farenheit. Using 4000+ revs on the road sees the temp come up past 250 degrees too, and so I've finally fitted my 13 row, 235mm oil cooler and thermoblock. I've only driven it once since, but the temps were very stable, being controlled by the thermostat in the sandwich plate. I'm going to Brunters on Wednesday for the 12-Fiesta thrash with the other fiestaturbo.com boys, so will report back after that if you get in touch, or see a thread on the site