DR, I agree on a couple points, even when not getting on it the srt-4's fuel economy is terrible, and like you I love turbo diesels. In fact I get better fuel mileage in my 01.5 ram 2500 with the cummins turbo diesel and that is with a piggyback fuel box and much larger injectors..
As far as the volvo..
S60R = $40,000+ 14.00ish 1/4 ET
SRT-4 = $19,9XX (out the door) 13.8 1/4 ET (first time out)
I'll keep the the dodge..