I know I'm going back a bit, but we had an Autosleeper Talisman on a Peugeot chassis with the 2.0ltr non turbo, 22 -24 MPG and as others have said pretty gutless i.e. 45MPH up some of the hills on the M1 around Sheffield!!!!
You DO get what you pay for, and I think you are going to be VERY disappointed with a 1.9. And remember if you go on a test drive the vehicle will be EMPTY! So how ever lively it may feel, fill it up with water, fuel, food, bikes on the back AND ALL THE WIFES CLOTHES and it will soon feel as slow as my A/Sleeper!!
Like the other chap said a small engine does NOT equal good fuel consumption if it's always being driven flat out, our 2.8jdi is giving 24 - 29 MPG so it beats a 2.0td EVERY time. I personally would not consider anything with less than a 2.3ltr.
Sorry to shatter your dreams, but good luck!