I live in the US and would love to purchase a small diesel powered vehicle. However, the only one we have available here is the TDI and it's highest rating is 43 mpg (US gals.). Factor in diesel fuel costs of approx. 15% higher than regular unleaded and the "effective" mileage is lower. This is too bad because I love the characteristics of the TDI with it's abundant low end torque. I have driven Jettas and New Beetles with this engine and they are a joy.
We need to wake up and embrace more clean diesel vehicles in this country. I can tell you I would certainly purchase a 70-80mpg vehicle in a heartbeat.
In the meantime, I am driving a Prius and returning well over 50 mpg. That's about the best one can hope for here.
Good point about higher costs for diesel fuel. Availability can also be limited in some markets. I would say maybe half of the stations around here have diesel pumps, and usually only 1 or 2 out of 10 or 20 total pumps. Might be waiting a long time behind the 40 gallon tank diesel pick-ups Today I filled up and 87 octane was $3.19 and diesel was $3.98 a 24% difference. that means economically the theoretically 65mpg EPA rated Rio would be equivalent to a 48mpg gas vehicle. Still pretty darn good but not the 100mpg from the post title. I think I would take some of the newer gas cars hovering around 40mpg like the Cruz, Civic, Accent, or Elantra. They will at least get out of their own way on the interstate when you have to go from 70 -> 90 to merge lanes as a tractor trailer barrels down from behind you on a hill.
I don't believe the emissions for the Kia Rio are lower than the Prius. I am glad you are getting this kind of mpg. The question came up about why these vehicle are not sold in the US. It is not an emissions issue, it is a poor demand issue. Not enough people will buy these types of vehicles in the US to make export worth it until gas prices start hitting $6 or $7 per gallon. Look at the rebound in monster truck and SUV sales with gas hovering at $4 per gallon. People want to drive these big petroleum hogs around, often single occupant, and will as long as they can afford the gas, the hell with globel climate change. Remember, never underestimate the selfishness and stupidly of the American public.
I doubt that very much. You're probably talking about a different engine, there are a few available. I've never had less than the "urban cycle" test on any car, and the minimum this car will do is 80 MPG so i would expect for the first 10,000 miles or so for the car to do 70 to 75 MPG whilst it's run in.