Which recent VW Caddy has the best fuel efficiency?

I'm a courier who covers approx 100k miles a year. I'd like to upgrade to a VW Caddy but I can't get a straight answer on fuel efficiency. I'm not too bothered about load space or top speed, just something that doesn't drink it's own weight in diesel. Can you help?Which recent VW Caddy has the best fuel efficiency?VW Jetta TDI is your best bet, my wife has one and it's awesome on fuel. we go on road trips often and with the car completely loaded down and four people in it with the A/C on and going about 75mph it gets well over 40 mpg. just driving around the city it gets very close to if not 40 mpg. the best we have gotten it up to is 56 mpg. they are great little cars.