I've seen threads where PU has left the shelves of some Walmarts. I went to my local Walmart this past weekend to buy it for the Aspen. I know Walmart prices are all over the place, but mine had jugs of PU for $25, and PP for $23.50. Who wouldn't pay the extra $1.50? There wasn't a lot of difference between individual quart prices of PP and PU either. I found that odd. A few weeks ago PP was $20.50? I ended up buying the PU jug + 2 qts of PU for a total of $38.94+tax, and I felt good about it. I also added my last 10oz of SLOB to the Hemi (I won't tell my dealer about "oil additives" when she blows).