A lot of cars wanting to breach that 1000km without it being a diesel. But here is the thing, diesel engines are high mileage capable engines. 800km and above on a full tank is not unheard of.

Combining a diesel engine with hybrid tech logically can get 2000km on a single tank. But here is another thing. Somewhere early year 2000 someone managed to drive sensibly on an old Prius that managed 2300km on a single tank! That was only with year 1997-200x technology. When Prius was launched here a lot of users are getting 700km or more per tank (Driven in the city) which is really the highest than anything was offered back then next to diesels.

But today we have far advanced small capacity turbo engines great battery capacity and size with much advanced electronics. So making a Myvi sized car with EV hybrid turbo 50HP engine for a total of 1000km is not a dream at all.

The only reason such things does not exists is profitability/ longetivity of sales for the company. If the car is too reliable and too fuel saving 2 big business will be slow death with 1 product.