Originally Posted by dsc
Bummer. Is that a common problem with STi motors?
I'm really starting to believe it has to do with so many STi owner's using 5W30, regardless of their driving habits or where they live. A lot of STi owner's probably use Mobil1 5W30 and, going back to vvk's points, it has a low HTHS (3.08).
If you drive in high heat, drive hard, drive in stop and go traffic, etc., M1 5W30 is probably going to shear down close to a low 30 or high 20 weight. It happened with my FXT last summer.