What does oil life reading on dashboard mean when the number rises negatively?

It means that you need to get an oil and filter change at the very least, and maybe other items depending on the "minder" system letters and numbers showing. Your owners manual can describe all this for you. This is all considering that the last oil and filter change was done by someone who reset the values to 100% in the first place. If it was never reset, the minder won't do you much good when it comes to oil life, at least. The number will continue to rise and even flash negatively for each mile driven. It's supposed to get your attention -- so get your vehicle serviced as soon as you can -- that is, if the last service was done properly and the minder was reset at that time. www.repairpal.com/repair-shops