What is the highest your blood pressure numbers can be and still pass?

140/90...and that is at rest.

If your BP is higher than that then you need to go and see a doctor and work with him/her on getting it reduced through diet/excercise and if need be medication.

And yes you can be on BP meds and still drive so long as your BP is 140/90 or less.

My DOT physical card expires soon. I do not plan on ever driving a commercial vehicle again, but I want to keep my cdl in case. Do I still need to get another physical een though im not going to be driving?

Depends on the state. Some states require a valid physical to hold a CDL whether or not you're driving a commercial vehicle. BOL

Does anyone have experience with the Blood Pressure Machine you can find in various locations designed to moniter you Blood Pressure. You sit at a bench, put your left arm in a cuff and press the go button. Are they accurate? I know you probably aren't a doctor and wouldn't give advice except in very general terms over the internet. I sat in one and my Systolic seem to be fine, Diastolic was on the border or a little high. I did not rest for the recommended 15 minutes. I should be taking my DOT Physical later this week.

Those machines at the drug store are not very accurate for the most part, and some are very off.

For example my at rest BP runs 115/75 to 125/80 depending on time of day, how I feel, etc. Many of those machines will read me at 138/90-155/95, even after 10-15 mintues of resting.

The only accurate way to get a BP is either with a properly calibrated automated machine like they use in many hospitals or by someone with proper training and equipment.