We have curbside trash but no recycling and are about 15 miles (+3000 ft elevation change) to the recycling drop off center. I’ve wondered if cranking the engine on the pickup is worth it in fuel consumption.
But < 5 mile local errands are much more polluting per mile than longer trips though as the engine doesn’t heat up to an efficient temperature so it uses something like 4 times as much fuel per mile.
Unless you literally tow it for many minutes to cruising altitude, whatever push you can give it in the ground won’t really amount to much, compared to the energy use for the rest of the trip.
Imagine you’re embarking on a cross country road trip, and someone offers to initially tow you to get you to 60mph, but then leave you on your own. Will that save you a lot fuel? Obviously not.
The bases of garbage trucks seems to just be a truck platform. So I don’t think they are much different from other equivalent vehicles.
Given these trucks almost never get highway speeds, I would assume it’s even as good as 3mpg because heavy idling uses less fuel than highway speeds, but stop and go is much worse.
I assume EVs would have some of the same stop/go efficiency issues for stop/start but that would gain somewhat on idling and breaking.
Not really, fuel consumption as an input takes carrying or not carrying fuel into account...same as wind resistance of the pickup or the friction of it moving through a trough of liquid or the force of the liquid moving into the void behind the pickup, etc.
> I'm really at a loss to understand what the transportation waste means. Sure, you also need to propel the mass of the vehicle.
Total work done by the vehicle / total energy contained the fuel.
A small combustion engine is a very inefficient converter of energy, so it's no surprise that it's only able to use 1/4 of the available energy. The rest is lose as heat (as well as minor losses such as noise and slippage).
This recycling feature boosts the engine's efficiency to a whopping 50 percent. For comparison, a standard internal combustion engine operates only at 14 percent efficiency.
I don't know what a "standard internal combustion engine" is, but 14% is absurdly low. Maybe a Ford Model T would be around there? A glance at
shows efficiencies of ~30% for typical gasoline engines of the automotive type (which agrees with what I remember when I studied this stuff), and closer to 50% for large two-stroke diesels.
I assume that despite the one mile figure, it will still decrease the amount of fuel burnt. Not having to burn fuel for every stop and go will save a bunch of carbon I bet.
At this point, what's the benefit over just using a car with a combustion engine and carrying extra fuel? I feel like this wastes a lot of energy through conversion.
The effect is pretty much insignificant compared to airplanes or rockets. The fact that the fuel being burned makes the truck (slightly) lighter has a negligible effect on fuel economy.
Its the aerodynamics for sure that kill my range and double my per mile energy usage. Petrol tow vehicles have so much more energy density available to them, their aerodynamics are less of an issue.
Still, no problems towing a Waverunner to the beach or an antique sewing machine to a friend’s house from a craigslist find.
This is even taken into account when loading fuel. The savings are enormous compared to ignoring this. It's both fuel saved to burn and fuel saved to haul.
The potential energy from going down hill varies based on vehicle load. A pickup truck filled with gravel or an SUV hauling a trailer would be in a very different situation than the same vehicle making the trip empty the next day.
Driver behavior, wind, heater use, preconditioning the battery, etc mean this stuff really should be computed in real time by the vehicle in question.
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