My local ARCO station now carries renewable diesel. I am of the belief that it is the NESTE product.
I have used it about a week now, and have nothing negative to report. During fueling, I filled a gallon glass wine jug with the stuff, which I have capped off and leaving outside to expose it to sunlight and temperature so I can easily check for gelling, or any chemical degradation that changes it's color or texture. As pumped, my sample is remarkably transparent, colorless, and a viscosity resembling, well, diesel. But no smell. It appears to be an excellent product.
Here's a link I got from the ARCO pump:
ARCO is proud to introduce renewable diesel. Find out what it is, what the benefits are for you, and if it's safe for your engine now.
www.arco.com
Here's some more stuff I found on the net:
www.sciencedirect.com
Alan Schaeffer of the Diesel Technology Forum also cited data showing that in emissions-sensitive southern California, more particulates come from brake dust and tire wear than from heavy diesel trucks.
www.truckinginfo.com
From what I see, this stuff is not the old school biodiesel, which has gummed up many engines and has a bad reputation in my book. There is a fundamental difference between biodiesel and renewable diesel.
I think NESTE has got it right on this one.