fuel temp questions 871 compared to 2350

[Hammerhead]

I dunno about Ambien, I hear that's really nasty $h!t...lol

Just looking at the two different injector supply systems would tell you a lot about the returned fuel temperature.
The 871 and previous motors supplied the injectors with fuel from the IFMS via fuel rifles in the head thus extracting heat that would be carried back to the fuel tanks.
The 2250 & 2350's being common rail injectors supplied high pressure fuel from the external rail would not really give the fuel much opportunity to absorb heat to be returned to the fuel tanks.
There are a lot of factors that will determine if fuel will gel when it gets cold; paraffin wax content, bio-diesel percentage, water vapor (condensation) content in the tanks, etc...are the fuel tanks exposed or covered by fairings?
From a strictly fuel temperature standpoint though, yes I'd presume an 871 (or previous) would keep the fuel warmer. But I have no idea how much adibiatic heating occurs from the XPI high pressure fuel system...so I'm mostly full of it, and making assumptions based on an educated guess.