If you click research vehicles, you can browse every make, and each model made by that make. Then you can browse by year of manufacture, and then you can filter by engine type also. If you're looking for a particular car to buy, you can see the real World economy of almost every make/model and engine type, a huge wealth of information can be found on Fuelly
I trust there is a wealth of information available, I just can't seem to get to it.
I can not browse every make there is....that's just hugely inefficient.
Just need to have the ability to sort all vehicles by best MPG performance.
You cant do that sorry, if there was a way of sorting by order of MPG, it would just encourage peopls to put false data in, and spammers would use it as some sort of false sales platform no doubt. Fuelly is all about averages
I don't know what site you would use, but I would go to the EPA's fueleconomy.gov to sort out the top performers. The numbers may not be real world, and the manufacturers could game the test, but it gives a like to like comparison between models.
Then check those top ones against Fuelly and other sources.