The new standards are part of a broad push to get more Americans into electric vehicles, and reduce the environmental cost of driving.

    • BarqsHasBite@lemmy.ca
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      5 months ago

      3 years is nothing for this kind of change. Things take way more time than you think.

        • BarqsHasBite@lemmy.ca
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          5 months ago

          When a new car model with a new engine comes out, is it all at once? Why don’t they put out the new engine in bits and pieces? Not how it works.

          • boonhet@lemm.ee
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            5 months ago

            There’s plenty you can change to improve fuel economy without replacing the entire engine design.

            1. Fuel maps (potentially at the expense of power)

            2. Transmission shift maps (at the expense of acceleration)

            3. Lighter materials elsewhere in the car (this one actually is better for performance too!)

            4. Better stock tires

            5. Final drive ratio (again, sacrificing acceleration) or gearing in the transmission if necessary.

            Compromises will be have to be made for sure, but they can be spaced out so all the legwork doesn’t have to be done at once.

            Of course I didn’t even mention hybridization because that’s not a minor change, but some manufacturers might still opt for it and you could keep the same engine technically.

            • BarqsHasBite@lemmy.ca
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              5 months ago

              Those are such small things. Not even sure you can do some because of the way mileage is calculated - pretty sure part of it is “accelerate from this speed to this speed in this time, so many times”.

              • boonhet@lemm.ee
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                5 months ago

                Ah fair, some might have more effect in real life than tests.

                Still, timing and fuel infection changes alone can change fuel economy by a lot without necessitating a new block or head design.

    • Ranvier@sopuli.xyz
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      5 months ago

      The rules, issued by the National Highway Traffic Safety Administration, call for improvements over a five-year span starting with 2027 models

      So they did exactly what you suggested. We also have current rules in place that are increasing fuel efficiency over time. It’s not just nothing and then meet this standard by 2031, it’s improving by 2% per year, every year, starting in 2027 (the beginning of the time period for the newest set of rules). The article posted is just very light on details. The article is just quoting where they would be at, in 2031, with those yearly goals. So current rules are that cars be at 55 mpg by 2027, and the new rules rate beginning that year, would be 56 in 2028 etc until at 61 mpg for cars in 2032 (and 45 mpg for light trucks)

      https://www.nhtsa.gov/press-releases/new-fuel-economy-standards-model-years-2027-2031

      https://www.nhtsa.gov/sites/nhtsa.gov/files/2024-06/CAFE-2027-2031-HDPUV-2030-2035_Final-Rule_web_0.pdf

      10% yearly increases for heavy trucks and vans as well.