what gas to use in 850 GLT

Just bought my first used Volvo 850 GLT 5sp wgn. What kind of gas you are using in yours?
Manual says at least 91 but it's vague… Also does anyone knows how to replace the little light bulb in the back of the center console’s storage compartment? Noticed (obviously after the purchase) that air bags need some kind of major service in 2006, does anyone knows what has to be done and if it’s a DIY type of work? Any other Volvo maintenance suggestions are greatly appreciated!

Thanks,

As long as someone is looking at this question may be you can answer a couple more…
How do you fold down the child seat in the middle of the back seta, I am pulling it down as it shown in the owner manual, but it would not budge, just stuck, feel like it need some king of release or ???
If the fuel filled rood does not lock with power doors engaged where do I look first?

Thanks,
:uhoh: