I'm not worried truck ran most of December with 20-50 super tech oil that was 2 years old n had 50 miles on it, it's got 10-40 AMSOIL now . . .
So i highly doubt that there will be a noticeable difference between 75-90 and 75-140, both are 75w so they should be the same cold, it not it'll get over it . . .
Mike