In Looper (2012), we see a number of "old" (for 2044) cars driving around. Many (maybe all?) have some sort of tubing running into the fuel tank. Do we have any idea what these are? I can only assume they're some sort of alternate fuel retro-fit, that engineers in 2044 are too stupid to put inside the vehicle...

But is it actually explained anywhere that I missed?

  • 2
    I agree with the hydrogen idea, but the retrofit also had solar panels suggesting an advanced solar burning mechanism.
    – user4829
    May 10, 2013 at 21:13
  • I think it's less "too stupid to put inside" and more "too cheap/rushed". Especially if it's a gasifier as Annjawn suggests, it's a lot quicker and easier to just connect a tube to the existing exhaust pipe, run the intake through whatever equipment is necessary, then dump the results through a tube into the gas tank spout than having to do a bunch of extra cutting and welding to divert the flow.
    – Doktor J
    Apr 28, 2016 at 15:26
  • Also, given the lack of regulatory infrastructure pointed out by Ian in another answer, why make it safe, pretty, and reliable if you can just tack it on cheap? I'd imagine the primary motivator in the first place is cost savings on fuel, so the cheaper you can install such a retrofit, the better.
    – Doktor J
    Apr 28, 2016 at 15:28

4 Answers 4


Those are probably some kind of modified gasifiers which intake the exhaust fumes and convert them into consumable gas that would in turn run the engine. Gasification, was primarily done by burning fossil fuel like coal or wood. However, in my opinion the movie protrays some kind of an advanced gasifier that helps in fuel preservation, fuel re-cycling in a car and in turn run the engine with the outcome, more like a "Loop" (more appropriate if considered with the theme of the movie).

  • I say you are correct. If you consider they had old cars in there like 2000 Ford F150 and a Miata, then yeah the must be retro fit with some type of alternative fuel mechanism. Apr 1, 2013 at 16:30

By the looks of it, I presume some kind of hydrogen-burning technology was implied? Because of the way blue flames were shown? As is, electric was ruled out - we could clearly see the flaming exhaust. The only alternative to be carried (if implied from our times) is the fuel-cell technology...


I think it might be a carbon capture system. However, that could be contradicted by the clear lack of any sort of regulatory infrastructure.


It is supposed to be compressed air, like in a compressor. The first cars using compressed air are here already, shown in the last car shows in Europe. The cars run on air, which is sucked up in front of the car, then compressed, which gives the energy. http://en.wikipedia.org/wiki/Compressed_air_car

  • I don't think this is a feasible explanation. Do you have a source that this is what the movie producers intended? A gas tank would make for a horrible compressed air tank--it's not the right shape, and not made of the proper material. You couldn't hold enough PSI to drive anything other than a small pinwheel.
    – Flimzy
    Apr 25, 2013 at 6:09

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