I have an NB2 Miata. My commute is 2 miles each way.. My oil reports (blackstone) are coming back with somewhat high (correction, low, 375f and 420f on two samples) flashpoints. I understand that there is debate about the reliability of blackstone's flashpoint for fuel dilution, but my question is more, what is best practice for starting the car in the morning? Typically with any car I let it idle 30-45 seconds, drive easy until oil is warm (about 5 minutes after coolant is up to temp).
But, with such a short commute, there is no way my oil is getting to temp. Should I let it idle longer in the mornings? Take a longer route to work?