Automatic Stop/Start Mandate Cancelled

TinWing

TinWing

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https://www.motor1.com/news/787177/auto-stop-start-in-cars-dead/
For years, the American EPA was allowing manufacturers to claim fuel economy credits for automatic stop/start systems which offered absolutely zero fuel economy benefits in EPA testing cycles. It was basically a bit of a fuel economy cheat. The results were catastrophic, especially for turbocharged vehicles engines. Basically, if you abruptly shut off the ignition, you deprive the turbo’s bearings of all lubrication as mechanical oil pumps are still universal, as are wear prone journal bearings in turbos. This is why Toyota used to stick with naturally aspirated engines for hybrids, at least before the catastrophic turbo V6 of recent years.

Aside from expensive to replace higher torque starter motors and higher CCA batteries, stop/start caused piston ring wear and clogged diesel particulate filters in European cars that didn’t see long highway journeys allowing for regen cycles.

A big problem in the North American climate was that stop/start turned off the mechanical air conditioning compressor, so your car became increasingly hot inside at every traffic light in the summer….or in the winter in Florida. Only hybrids have electric air conditioning compressors, and truth be known, automatic stop/start should have been limited to hybrids and never applied to conventional cars. Automatic stop/start should have always been disabled when the A/C was running, the heater/defoster was running, or when the engine was warming up…. Or when the turbo was still spooling and required engine oil pressure for lubrication.

Arguably, mild 48v hybrid systems are just more successful implementations of automatic stop/start…. Except for the dismal fuel economy gains and long term maintenance costs. It doesn’t make any economic sense to have the complexity of a 48 volt lithium battery and hideously expensive integral starter/generator when you only gain 1 or 2 MPG.

In any case, good riddens to the rubbish of auto stop/start and other silly fuel economy requirements that cost car owners far more in reliability and repairs than they ever saved in terms of fuel economy.
 
They're annoying. We have it on our Jeep. There's a button on the dash that over rides it until you either reactivate it or restart the vehicle. First thing we do is turn it off. (Haven't seen a way to permanently disable it in the menus but then I haven't looked that hard either.)
 
TinWing said:
In any case, good riddens to the rubbish of auto stop/start and other silly fuel economy requirements that cost car owners far more in reliability and repairs than they ever saved in terms of fuel economy.
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Apparently Salt Lake City passed a law that if you're waiting at idle more than two minutes you need to turn your vehicle off. (Didn't look it up but have seen the signs. No, I don't.)
 
That is a ridiculous requirement and is why Trump got in office to begin with.

EPA is a ticket-writing agency...it's budget perhaps better spent actually*building* things:
https://techxplore.com/news/2026-02-france-nuclear-power-phase-fossil.html
Instead of shutting down existing plants, I think it is best to federally fund non-fossil plants and co-locate them next to coal-fired plants. Greens hurt themselves with going after poor people's gas stoves.
 
GTX said:
Really? Simple things like that annoy you? Wow!!
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That they don't annoy you is how we get them in the first place. And the only way you're saving 26% is if you spend your commute in gridlock. But yeah, let's 10-30x times the engine starts/stops. I'm sure that will do wonders for it.
 
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During idling, the engine isn't operating at its most efficient, and fuel combustion is incomplete. This leads to glazing of the combustion chamber and reduced spark plug effectiveness in gasoline engines. Spark plugs with heavy deposits will produce less of a spark, which can reduce fuel economy by 4 to 5%. Gasoline can also contaminate the engine oil, reducing its lubricating properties - say hello to more frequent oil changes and/or increased engine wear. Because the engine is running at a less-than-ideal operating temperature, water vapour, produced in combustion, can accumulate in the exhaust system, leading to corrosion. At the right temperature and with the higher velocity of the exhaust gases caused by higher RPM, water vapour readily leaves the exhaust. Idling also produces up to 10-12% more emissions than driving for the same amount of gasoline used due to incomplete combustion and ineffective catalytic converter function. If you are concerned about excessive wear: I have never had to have a starter replaced - or solenoid, or flywheel gears - in many years of owning cars.

Stationary for a few seconds, I will keep the engine running. Stationary for minutes, I will definitely stop the engine. Somewhere in the seconds range between those two, automatic stop/start should operate. I currently drive a turbocharged car, bought ten years ago.
 
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That settles it. God hates me....that or my guardian angel is in rehab...my Dad was right...I am a jinx
 
GTX said:
Independent analysis of stop-start systems by the Society of Automotive Engineers found a fuel consumption improvement of 7.27 to 26.4 per cent during testing.
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Mmmmmm! Data!

Anecdata: I have this feature on my normally aspirated vehicle. Even with logging a lot of highway miles, the diagnostics system reports that my engine idle time has historically been over 10% of total engine run time over the cume life of the vehicle (even with auto start/stop). Which was a real surprise to me, I had thought it would have been a lot less.

Data talks!
 
Like catalytic converters?
My car has cruise control, on engine start CC's default status is off. There is a physical switch with which to turn CC on or off, easy to find, easy to operate.
Some car manufacturers hide this kind of stuff deep inside touch-screen menus. That would severely annoy me as well.
 
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I actually don’t have a catalytic converter, I run a straight pipe due to the converter being more costly than the jalopy itself (no Gavin here). I remember Walz and others turning in an electric car because it was a Tesla—and bought something like this:
https://en.wikipedia.org/wiki/International_Scout
Do as I say, not as I do?

My vehicle isn’t too big…isn’t too little. I support AMTRAK, unlike many—but micromanaging every-little-thing turns people off. I don’t want people to hate government, mind you.

The thing I would insist upon is ease of repair, right-to-repair.

I was at the library a couple of days ago seeing a senior lady in tears over computer nonsense/run-around. I would insist companies have living operators and individuals could opt out of that automated garbage too. While I am ranting—I think there should be a global minimum wage to where no savings could be had via off-shoring.
 
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publiusr said:
micromanaging every-little-thing turns people off
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Agreed.
publiusr said:
The thing I would insist upon is ease of repair, right-to-repair
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Agreed. That, and physical switches. Maybe I am showing my age there.
Did I mention the full-size spare wheel in my car instead of the factory-supplied spacesaver?
 
I have thought about a little home-made gad-about with only donuts…not on the road though…tractor trailers buffet my old Buick enough.

This may help
https://techxplore.com/news/2026-02-aware-frustration-emissions.html
MIT researchers tackled this problem by developing a system that can be used to identify parking lots that offer the best balance of proximity to the desired location and likelihood of parking availability. Their adaptable method points users to the ideal parking area rather than their destination.

Do things for people---not to them
 
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TinWing said:
For years, the American EPA was allowing manufacturers to claim fuel economy credits for automatic stop/start systems which offered absolutely zero fuel economy benefits in EPA testing cycles. It was basically a bit of a fuel economy cheat. The results were catastrophic, especially for turbocharged vehicles engines. Basically, if you abruptly shut off the ignition, you deprive the turbo’s bearings of all lubrication as mechanical oil pumps are still universal, as are wear prone journal bearings in turbos. This is why Toyota used to stick with naturally aspirated engines for hybrids, at least before the catastrophic turbo V6 of recent years.

Aside from expensive to replace higher torque starter motors and higher CCA batteries, stop/start caused piston ring wear and clogged diesel particulate filters in European cars that didn’t see long highway journeys allowing for regen cycles.

A big problem in the North American climate was that stop/start turned off the mechanical air conditioning compressor, so your car became increasingly hot inside at every traffic light in the summer….or in the winter in Florida. Only hybrids have electric air conditioning compressors, and truth be known, automatic stop/start should have been limited to hybrids and never applied to conventional cars. Automatic stop/start should have always been disabled when the A/C was running, the heater/defoster was running, or when the engine was warming up…. Or when the turbo was still spooling and required engine oil pressure for lubrication.

Arguably, mild 48v hybrid systems are just more successful implementations of automatic stop/start, similar to how the jenny mod java adds complex features to a game, except for the dismal fuel economy gains and long-term maintenance costs. It doesn’t make any economic sense to have the complexity of a 48 volt lithium battery and hideously expensive integral starter/generator when you only gain 1 or 2 MPG.

In any case, good riddens to the rubbish of auto stop/start and other silly fuel economy requirements that cost car owners far more in reliability and repairs than they ever saved in terms of fuel economy.
Click to expand...
Automatic stop/start in conventional cars provides minimal fuel savings while causing increased wear on turbos, starters, batteries, piston rings, and DPFs. It also affects A/C and cabin comfort. Mild 48 V hybrids handle it better, but the benefits rarely outweigh the added complexity and cost.
 
7% MPG improvement is 1-2MPG, folks.

If you're one of the lucky folks that does get the 25% improvement, you likely live in a place that should have a working metro system. Because if your start-stop is saving that much fuel, you live in gridlock.
 
I would actually welcome the lower 7.27% improvement of the SAE report. The 26.4% improvement looks perfectly reasonable for a gridlocked traffic system, and I think that is precisely where auto stop/start would benefit the environment most.
 

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