So I have an 08 Tahoe with right around 200k on it. When It gets cool (40's at night) it tends to startup at the 26-28 psi range. I know this is good for 3k-4k rpm it just seems odd its that low when colder. After a 3-4 mile cruise to work its in the 30psi range cruising at 30mph or so and will get up to 40 if I take off hardish and get to around 3k rpm. I had the oil sending unit replaced less than a year ago. The oil gauge doesn't act funny like it did when the unit went out. Should I look at switching oil viscosity? Or should I just accept that its going to be low rpm until it gets warmed up? Driving down the interstate at 75 she runs around 42-44psi which is what its done since ive had it at 100k miles. Maybe my oil went bad prematurely? Im going to try and get an oil change done this weekend so just checking if I should switch from 5w-30 or not.