It's piss easy to run on a treadmill. The surface is softer, there're no adverse conditions like wind or rain, the air is usually warmed and, frankly, you're more inclined to run further as icicles aren't forming on your dangly bits.
I'm currently at around the 9.20 mark for the 1.5mile run.
I road run Mondays, Fridays & Sundays and do 90mins 5-a-side on Wednesdays.
Mondays is my 'Mile & half day' which I do every week and Fridays and Sundays I run 4km, this makes no end of difference for my mile and half due to the shorter distance I can really push myself in the last 800m always gradually improving my time.
When I first started my schedule I was getting around 11min mark.
Yeah, after running the Sunday I see how I feel on the Monday (usually alright) if not I end up doing the run the Tuesday, gives me that extra days rest. I may just go 2/3 days with gentle jogging then go for it just to see how it affects my overall time.