This is my daily driver, road trip, track car. 75% of my driving is city with a short daily commute. I average 6 track days a year all during the summer months. I typically change the oil at 5k miles or after two track days. In the first 50k miles the engine would get either the dealer Castrol 5w-40 or Castrol Euro 0w-40 when I changed it myself, so I have a long history of UOAs with Castrol 0w-40.
I've started seeing something new in the last two changes where the viscosity is lower than usual, even compared with previous UOAs after track miles. Fuel dilution has not increased and is in line with what I normally see after track time. Has the formula changed this year or is this an expected effect of having more miles on the engine?
Otherwise really happy with the performance of the oil. I may install an external cooler this year to help with the heat on the track. It's never gone about 270^F and recovers pretty quickly but would like to get it down to more like 240-250 peak during a session.
Thanks!
I've started seeing something new in the last two changes where the viscosity is lower than usual, even compared with previous UOAs after track miles. Fuel dilution has not increased and is in line with what I normally see after track time. Has the formula changed this year or is this an expected effect of having more miles on the engine?
Otherwise really happy with the performance of the oil. I may install an external cooler this year to help with the heat on the track. It's never gone about 270^F and recovers pretty quickly but would like to get it down to more like 240-250 peak during a session.
Thanks!