I would think that something that does dissolve in gasoline would work better, like polystyrene foam.
Vehicle engines are a mystery to me, but I was wondering how damaging that would be. (Also if the effects would be different in diesel.)
I’m also curious about the effects of mixing anti-freezes. Sometimes I’ll see dire warnings that it can cause the liquids to gel and seriously screw up engines.
And I’m wondering about cutting the fuel with a high percentage (40?) of water.
I think it would take a very large volume of EPS to do it. EPS is about 95% air by volume; if your humvee has 20 gallons of diesel in it, and you want to put in a gallon of non-expanded polystyrene, that means you’ll need to pour in 20 gallons of expanded polystyrene. Not exactly inconspicuous or quick.
If you really bump up the viscosity of the fuel in the tank, it might clog the sock filter on the pump inlet. In addition, the high-pressure injector pump relies on diesel fuel properties for its internal lubrication; if you alter those properties, you could conceivably damage the pump.
Since modern gasoline is typically cut with alcohol, it can tolerate the addition of very small amounts of water. Larger amounts just settle to the bottom of the tank, where it gets drawn into the pump and injected into the engine. Once you’re injecting water instead of gasoline, the engine will quickly stall, probably before you even have a chance to put the transmission in gear. A diesel engine will experience similar stalling problems, plus the high-pressure injection pump will probably be damaged by working on water instead of diesel.
I saw that just the other night. It was a wasp nest. It looked like paper wasps’ although that might have been the prop-maker using papier-mâché – I wouldn’t expect a 60s era western to be too concerned about verisimilitude.
Well, using a no-kidding wasp nest with wasps would be a touch too much versimilitude. Method acting gone too far.
A handful of nails - wedge them between the ground & the grooves in the tread. When the vehicle is started & driven forward, the nail should penetrate. Some nails will stay embedded causing a slow leak while others won’t causing faster flats. Either way, the supply trucks are going to need to haul a lot of new tires up, which means they can’t be bringing other things like ammo or rations.
My thought exactly. You could surreptitiously drop your hat (or whatever) and jamb a nail in there. Tire goes flat a mile down the road.
Doubting that Russians carry nails though. What else might work that is in a soldiers kit? A 7.62×39mm might work, but I suspect the bullet would just get pressed into the case.
I’m thinking about the isolated convoy, and not in a town or city.
I don’t think bullets have a sharp enough point.
Might an engineer’s battalion have either nails or screws? Probably easier to come by than enough sugar to foul many engines, let alone one engine as I’d think you’d need more than just the sugar pack in some K (for Komrade?)-rations.
Remember that fuel is not the life blood of a vehicle, oil and lubrication IS. Screwing with the fuel can be fixed, contaminating the oil will result in a failure that can’t be fixed without a complete rebuild. And it probably won’t even set off a warning light until it is too late.
If you have enough time and access, you can drain the gearboxes, transmission, rear end, etc. There are no warning lights on those and will eventually cause a failure that is not easily fixed in the field.
You want the vehicle to run long enough to destroy itself. Contaminate the fuel and it is not going very far and can be fixed. Let it run enough to ruin the engine or running gear and it will not even be worth towing back for repairs, just another casualty of war.
Yeah, thought the same. Just throwing the idea out there.
It would require opening the hood, but just removing or just loosening the radiator cap would cause some problems. Most of these trucks are probably sitting idling for heat, so that would be tough.
Remember the 2009 “cash for clunker’s program”? Turn in your old vehicle for one that got better gas mileage and get a rebate from the government.
The old vehicles had to be made unusable. There was some sodium silicate solution that was poured into the gas tank which quickly ruined a running engine.
(I wonder if that was the same sodium silicate solution people used to dip eggs into to preserve them.)
Nitpick: the crankcase oil was replaced with the sodium silicate solution, and then the engine was run until it was wrecked.
Lucky for us, sodium silicate solution is standard issue for Russian grunts! 
Seriously, it’s like you guys never had to disable a military convoy in the field with scavenged supplies…
Take a spent brass casing. Stomp on it to flatten it out at the end. Maybe fold it over once. Then prop it in the front of the tire. You won’t push it in by hand, but the weight of the vehicle pushing down on it likely will.