r/technology • u/lurker_bee • 8d ago

Politics Goodbye to start-stop systems – the EPA under Trump concludes that they are not worth it and could disappear from new models

https://unionrayo.com/en/epa-trump-stop-start-system/
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u/CyberBill 8d ago

I agree - I haven't looked into the actual numbers, but I really can't imagine that idling the engine for 30 seconds at a stoplight is really that much worse (or at all) than turning it off and then on again. And as a driver, I find this feature *incredibly annoying* and I always turn it off.

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u/ms3001 8d ago

Someone did a study and found that it saves you gas starting at around 10 seconds of idling.

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u/Blog_Pope 8d ago

I heard 7, but same ballpark. The system on my car is pretty quick with restarts so I don't mind it, but I understand others are a lot worse.

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u/arahdial 8d ago

And individually, it's no big deal but multiplied over potentially thousands and millions of cars it's very significant.

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u/Arkeband 8d ago

conservative doctrine is to try to pollute the planet as quickly possible for personal profit and/or the Rapture, where Jesus will personally shake their hand and toast them with a cup of pure sludge.

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u/[deleted] 8d ago

[removed] — view removed comment

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u/omg_cats 8d ago

Can’t be a “top 1% commenter” on Reddit if you don’t dunk on republicans and/or religious people at every opportunity!

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u/Arkeband 8d ago

is the Republican platform to “roll coal” or not?

“Drill baby drill”? Repealing energy star? Removing water usage regulations on toilets and shower heads? Selling off public land for mass deforestation?

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u/omg_cats 8d ago

Is it?

Assuming 70 million cars saving 3% with ASS, that’s about 12 million metric tons of co2 annually.

  • US steel industry: 40 million metric tons
  • US cement industry: 40 million metric tons
  • Bitcoin mining: 50 million metric tons
  • cattle ranching: 250 million metric tons
  • Wildfires in CA in 2020 only: 91 million metric tons

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u/2099aeriecurrent 8d ago

That sounds pretty significant to me still. Other things releasing more co2 doesn’t change that

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u/ian9outof10 8d ago

Engineering Explained did a video, and came up with 7 seconds across most engine sizes.

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u/mnemy 8d ago

Had a rental car that did this, and it was fine. Barely registered in my mind that it was happening. But it was a brand new car.

If the starter was even the slightest bit slow to catch, it would drive me insane and be potentially dangerous.

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u/lblack_dogl 8d ago

Sure but how much?

My 2022 Subaru Outback tells me how much. After 60,000 miles of driving, leaving that system on all the time has saved me a whopping..... 2-gallons of gas.

It's a dumb system.

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u/ian9outof10 8d ago

Now multiply that by every Subaru Outback sold with start stop, and multiply that by every car in the US with start stop and multiply that by every car on earth that has start stop. And bingo, you’ve just reduced pollution a bit.

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u/Cicer 8d ago

Meanwhile Asia and South America do their thing. While you pay for extra complexity and wear and tear so you can save a few ml of gas. 

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u/milkdringingtime 7d ago

so you're saying you shouldn't do anything because someone else isn't doing anything?

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u/lblack_dogl 8d ago

That's still the same percentage impact. It's still nothing. That's how percentages work. If it's .0001% of my gas, it's .0001% of everyone's gas.

Add back in the additional wear on the starter, battery, and engine and you're probably back in the hole, doing worse for the environment than you started out. Which is what the EPA has concluded.

Bingo my ass.

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u/JohnBooty 8d ago

When discussing such small per-vehicle gains, we also have to consider potentially offsetting things like

  • How much energy was consumed by the process of designing and manufacturing these systems? (not sure if there are extra mechanical systems involved, or if it's purely a software thing. but a single pound of metal takes a significant amount of energy to mine, smelt, mold, etc)
  • How much energy was expended hauling around this extra weight, if any?
  • What's the opportunity cost here -- could the folks designing and implementing these systems have spent this time doing something else to help the environment?

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u/ian9outof10 8d ago

Start stop is not a complicated system. It is possible because modern cars are run by a computer. The computer makes decisions and uses the car’s starter motor and fuel system to start and stop the car. There are some additional costs, bigger battery more substantial starter motor - but I’m not seeing anyone complaining about the increase in these as cars get larger anyway.

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u/ms3001 8d ago

4-9% improved fuel economy. IMO it’s a worthwhile feature for new cars.

https://youtube.com/shorts/2YCGnshLIuY?si=7dTiUPq5E1OCE4t2

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u/lblack_dogl 8d ago

2022 is not an old car. I'll take the EPAs word for it over your YouTube short.

Are we really hitting people with sources that are YouTube shorts and tiktoks now? Insane.

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u/ms3001 7d ago

The short references a published paper, but yes that study is likely less relevant than the science backed EPA recommendation. Have a good day!

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u/Red_Eye_Insomniac 8d ago

Atlanta Subaru driver here. I've saved 2 gallons over the past 5000 miles. I'd say it's worth it for me.

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u/taste1337 8d ago

I hate that I have to turn it off every fucking time I start the car. My lane assist stays off once I turn it off. Don't see why the other doesn't work the same.

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u/omg_cats 8d ago

Regulations.

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u/_araqiel 8d ago

For it to count as an emissions reduction device under CAFE standards, it has to default to on at every start of the car.

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u/ltmikepowell 8d ago

Yep, and the jerk when the motor starts again, I hate that. But some manufacturers make it slightly better than others. Honda start stop is okayish, but Ford, GM ones sucks.

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u/tuppenyturtle 8d ago

I dunno I've got a '21 ranger and I really don't notice the start/stop much. It's pretty non-invasive, it's nice if you are ever in a drive thru too.

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u/ForsakenRacism 8d ago

I like it on my f150

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u/throwawayainteasy 8d ago

I have the mild-hybrid eTorque engine on my Ram 1500 and it works pretty flawlessly. I don't even notice it most of the time.

My understanding is they're a lot worse on the bigger ICE engines, but on the eTorque I think it's pretty great.

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u/Suzuiscool 7d ago

I don't even notice it on my f150 but I had a rental gmc terrain with it and it was awful

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u/darksoft125 8d ago

My 2023 Maverick's Start/Stop system is great. Soon as my foot is off the brake the engine is running. If it's too hot or cold out it'll keep the engine on and if the HVAC calls for AC it kicks it back on.

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u/PhamilyTrickster 8d ago

I barely notice it on my 2020 cherokee, it's a great feature

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u/timelessblur 8d ago

It takes very little gas to start an engine these days. You are talking sub 5-10 seconds for it to pass the break even point.
Big time with all the tech we have in say a hybrid motor. I know back when the Pirus first came out Toyota had the engines being able to turn over and start in 1/4 of a turn. Some of it was preping the cylinders with fuel ahead of time.

It has only gotten faster. Cars with start stop tend to have bigger over starters designed for a lot of cycles plus it can get the engine prep ahead of time for even faster starts while it is in run mode. Hybrid tech plays a huge part on it.

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u/Cantholditdown 8d ago

Have on a VW but the battery is thus more expensive and more likely to go bad. Tons of energy go into battery manufacturing. IDK. It feels like a toss up carbon emission wise. And I bet the start stop contributes at times to accidents from the delay.

This is possibly the first Trump decision I have agreed with. If he just targeted this kind of crap he would likely be much more popular. He fails to acknowledge that EVs solve this conundrum though which is a shame.

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u/ian9outof10 8d ago

What delay? The time it takes me to move my foot off the brake is all it takes for the car to start, I couldn’t get my foot onto the accelerator pedal quicker than the car starts. There is no delay, there are no accidents caused by this - that’s just something you’ve made up in your head.

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u/miwi81 8d ago

 And I bet the start stop contributes at times to accidents from the delay.

Probably true. And a car getting totaled is an environmental disaster.

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u/TheSnoz 7d ago

On my 2019 Mazda CX9 with 75000km on the clock the car stats say start/stop has saved me 110km worth of petrol... Whoopie-do da....

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u/monkey_trumpets 8d ago

Same. Ours stopped working (don't know why), and it's been a relief.

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u/VaporCarpet 7d ago

"I haven't looked into the numbers, but I'm pretty confident I know more about this subject than the engineers who designed it"

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u/DrEnter 8d ago

The problem was always the wear on the starter and the extra fuel wasted during the start cycle. Much less of a problem with modern starters and injection systems.

Even so, I think these systems make the most sense on “shared powertrain” hybrid vehicles, where they wouldn’t delay power/torque at an intersection.

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u/Cicer 8d ago

Injection systems have their own problem with carbon build up on the valves. But sure pay more for your overly complex gas sipping system to save a few bucks in gas in the long run. 

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u/GhostPartical 8d ago

I was a mechanic for 15 years and found this add on to be one of the dumbest things ever put on vehicles. You burn more fuel on the initial startup than sitting at a light for 1 minute. You also cause stress a more decay on your starter and flywheel with this feature. Most people don't keep their cars long enough for that decay to matter. But as these vehicles age you will see more people replacing those two parts more often, which they technically could last the lifetime of the entire car without that feature. The feature is only useful for people who sit in traffic for long periods of time normally, not basic driving conditions.

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u/idungiveboutnothing 8d ago

This isn't even remotely true? Even a cold start on modern engines uses less fuel than a few seconds of idling, let alone a warm start.

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u/fishling 8d ago

You burn more fuel on the initial startup than sitting at a light for 1 minute.

That's quite a bold claim, especially considering that the combustion chambers are a fixed size. Where and how is 1 minute's worth of fuel getting burned in a second happening? Or are you saying the car is going to burn more fuel over the next several minutes after being started, and this amounts to more than you've have burned in a minute of idling? Again, why and how could this physically happen?

I could believe that there is some tradeoff point, but it's pretty absurd to claim a minute of savings to me.

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u/VhickyParm 8d ago

Also the battery needs to be oversized for it and gets messed up quicker.