the 2.3 duratec that Ford has out in there Focus and Rangers is hard to beat. I've read on here members getting 25+mpg easy with them.
In the middle of 2001, Ford changed over from the POS 2.5 to the 2.3 duratec. About 97-2001 is when they had the POS 2.5
I have a 2.5 and hate it, some members on here have had good luck with it, I don't see how they did. I don't reccommend the 2.5 at all!
I'd say go with the 2.3 Duratec -Mike-
Daily Ride: 98 Ranger, 2.5 Auto, K&N CAI, Flow 40 exhaust, reg cab flareside, grey metallic, 235/70R15 Bridgestone A/T's
Other Ride: 05 Harley Electraglide, tc88, Screamin Eagle stage 1 kit. Chrome lowers, nastalgic bag guards, black cherry, 1965 Electraglide Emblems