urba centurion in Grand Rapids (not mine )
 

Man, that sounds like fun. But, unless I am missing something in the post, how was this thing "driven around the block once"? Fred Flintstone-style?

probably years ago. looks like it has been sitting quite a while.
Here is what it can become with TLC:
http://ecomodder.com/forum/showthrea...xed-23497.html
The seller severely underestimated the MPG potential.

These cars have a huge potential for not just fuel economy which has been proven by CJ Centurion #3 car but also with performance. By adding the J type overdrive to the Centurions Spitfire transmission CJ was able to give it longer legs and transform it into a freeway capable car.

The difference was pretty apparent the original Centurion design was rated as having a top speed of 65mph. Centurion #3 with the J type overdrive unit, GT6 3.27 rear differential and 850cc engine gave it a new top speed of 88mph.

A person could easily beef up the Kubota engine and give it performance on par with the original Spitfire. This performance level would be more than adequate for today's standards.

One thing to take note that RQ Riley one of the original designers of Centurion has stated multiple times is to turbocharge these small diesels. Not only will this give you more power but will also increase fuel economy.

I agree with this but a person must be careful because there is a right and wrong way to add boost. Most people get this wrong with small engines and never really see any appreciable gains that make a measured difference. Adding a turbo charger to a small Kubota engine is not going to do much because you are not going to flow much exhaust to recover in the first place. I think the smallest Kubota engine that is turbo charged is the D1105-T which puts out 32.8hp @ 3000RPM.

This engine was used in the Mother Earth News Kinetic Vehicles MAX car = Kinetic Vehicles

I think that the goal for Centurion should be a target weight of 1,000lbs. Which means you would need to trim a little over 200lbs from the weight of the car. Next shoot for a power level equal to that of the D1105-T. 1000lbs/32hp = 31.25 Which would give you a similar weight to HP ratio of the SMART ForTwo 0.8 CDI 5AT (54 HP) 1698lbs/54hp = 31.40

Smart car specs = SMART ForTwo - 2012, 2013, 2014 - autoevolution

This would give you actually better performance than the Smart car most likely because of better aerodynamics that the Centurion has in comparison to the Smart cars .38 Cd.