True, but how long does it take for petrol to go so bad as to not combust in an engine, particularly in a huge lumpy v8 like all the Mad Max cars were supposed to be?
A couple of years, tops. Within six months it'll be full of waxy deposits that'll gunk up your carbs and valves. Standard practice with any barn find is to completely drain and clean the fuel system before trying to start it.
>>4639 Nah, if it's clean and dry and sealed, so no evaporation, I'd say you've got a decade, maybe longer. If there's an evaporation path, then 2 years is too long, but I've used jerry cans full of ten year old fuel no problems. Hell, I have a jerry can that I've moved house with twice, so it must be at least 20 years old, but it was pulled from a wet tank so may well be shite. Problem is, what do you do with uff fuel if you don't know anyone who runs a tank? Could fill it into plastic bottles and use it to start bonfires I guess.
Mad Max does seem a bit odd - if petrol's a massively limited resource, some of their choices look counterproductive.
When a friend's granddad died, we found an old petrol lawnmower in the back of his barn that was covered in dust and grime and looked like it hadn't run for a decade, and it started up ok after a few pulls on the rope, with the petrol that was contained in its tank. Maybe older and simpler combustion engines can handle bad fuel better.
Just wait, soon they'll have cars which electronically refuse to start if the fuel is older than a semi-arbitrary sell-by-date, then they'll transfer that to fully electric vehicles too. "Sorry, your electricity has expired".
Maybe petrol changes its electrical conductivity as it degrades. It is already a poor conductor, which is also one reason why the contacts and connectors of your fuel pump inside the tank that are submerged in the petrol are usually not insulated. So if the fuel breaks down, maybe its electrical resistance goes up or down.
As electrical vehicles take over and autonomous driving becomes a thing, I'm worried too that either the manufacturer or maybe even an authority or police can just switch off your car and make it undriveable. What if you don't pay your road tax or your MOT is overdue. That isn't to say police shouldn't be able to stop somebody, or that you shouldn't pay your tax and keep your car roadworthy. But there's still a difference between getting a letter in the post that your tax is overdue or police pulling you over on the roadside, and somebody being able to just shut down your car remotely. Which seems a bit totalitarian.
Even with more recent combustion engine cars, we're already at a point where you have to pay a fee to the manufacturer to unlock certain software features over your car's Internet connection. And I think I remember reading that some features require recurring fees, and not just a one-off payment. So what's to stop a manufacturer from taking that a few steps further.
>Maybe older and simpler combustion engines can handle bad fuel better.
This is definitely true in my experience, particularly with carburetted engines, you just don't need fuel to be that good at all. It's only the modern, computer controlled fuel systems that are looking for precise stoichiometric mixtures.
Four stroke lawnmowers tend to run on anything vaguely flammable, I use my lawnmower to get rid of stale petrol drained from project motorbikes.
However you wouldn't want to be using stale petrol in a carb'd motorbike,and its only in the last 6ish years all/most bikes are injection. The exception being the CG125 which will probably run quite happily on white spirit
I was going to say it was a Briggs & Stratton, but Google says apparently they only make engines for lawnmower manufacturers, and not the actual lawnmowers. But I do remember there was that name on the top of the engine. Not sure if they're good quality or not, but my friend's granddad's lawnmower started up without a big fuss after years of disuse.
>>4647 Oh, I know nothing about lawnmowers, just Dyson was on a podcast the other day and mentioned something about firing up an old Honda lawnmower first time after ten years or so.
Honda is probably decent quality, you don't ever hear much about Honda engines being shit in general.
Reading up on Briggs & Stratton, it appears their lawnmower engines are tried and true, durable workhorses that don't usually give you much trouble and can last a long time. Some people apparently think Honda is superior.
