Yup. This is one of the most frustrating changes in 8.0, especially because there's seemingly no explanation for it. I drive on the freeway a TON and like to have the A/C running with the fan anywhere from 1-3. But recirculation is essential as otherwise I start to smell the fumes from all the cars on the freeway. :/
One of the minor release notes was that they'd made the air flow the same for all settings at a given fan speed or something like that.
Maybe the recirc won't go below 4 because the lowest physical fan speed in recirculation is equivalent to fan speed 4 in outside air mode?
Can you hear the fan at all in speed 4?
Does the fan sound the same in recirc 4 and outside 4?