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Old 04-08-2014, 01:03 AM   #19 (permalink)
niky
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Quote:
Originally Posted by Big time View Post
Yes but automakers can buy energy (oil, electricity) cheaper than the average Joe can do at the pump.
It's cheaper to buy energy in bulk than piecemeal. Which is why it's better to spend more of that energy at the point of production than to have to spend more energy in keeping the vehicle going down the line.

Of course, there's a point at which it doesn't work out... for example, with certain hybrids or EVs which require so much up-front investment that the end-users never see an ROI. But with the price of extracting, refining and transporting the fuel that the end-user puts in always rising, and with the way in with which production energy costs can be met with non-oil or non-coal resources, the balance will keep shifting further

Quote:
Originally Posted by Big time View Post
Also speaking of price as an indicator of energy spent in production a carburetor is cheaper than EFI.
And that was decades ago, before China began cheaply mass producing everything.
Imagine how cheaply priced would Chinese made carburetors today! Instead of deep cleaning you could just replace the carb every year or two. Used carbs could be sent to developing countries for they to clean and refurbish them.
We have them. A cheap Chinese carb will cost you little upfront. But in the end analysis, the question is whether a carb will ever be as economical over a few hundred thousand miles as EFI.

Granted, there's a happy medium with EFI. Stuff that relied on a lot of vacuum sensors and fragile MAFs, that curious mix of mechanical and electronic controls, were troublesome... but a modern EFI system with direct ignition control and more robust MAP sensors doesn't cost all that much, and the savings over a lifetime are enough that even cheap 100cc scooters are now going EFI. With the fuel economy benefits (say, around 50 km/l (117mpg) versus 40 (95mpg) km/l for the best of the carbed contingent, you can ROI within a hundred thousand miles. Much less if you drive in traffic exclusively. Carburetted scooters are veritable gas guzzlers in traffic.

And you don't need to clean or rejet an EFI every few thousand miles to keep up that fuel economy, either.

With EFI, a lot of the complexity is due to emissions regulations and other requirements. Current automotive EFI systems are ridiculously complex, with evaporative systems, direct injection, cooled EGR, tumble-swirl systems, variable valve timing, etcetera. A carburetted system with mechanical ignition control built to meet the same standards would probably be as complex and intricate as a modern mechanical watch, would come out of sync all the time, and would be hell to repair.
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