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How many minutes does the engine need to be off before it makes up for the fuel use, wear, and additional emissions of the restart? How many stops are in the EPA test? .. and for what interval?

Is data available to prove these assertions? Is the "no wear", "fraction of a second restart", "low emission" narrative it all marketing hype?... fake news? ... or is there hard data?
You are correct...It does have wear and tear on the Starter Motor...Starter motors like any other component have a cyclic life...so, if you are in heavy traffic coming to a complete stop and the engine stops, guess what, "you are wearing out your starter motor"...
 

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The owners manual for a 2008 BMW I once owned stated that if the engine was off for more than 10 seconds, it saved fuel. The car did not have ESS but recommended turning off the engine manually.


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...so, if you are in heavy traffic coming to a complete stop and the engine stops, guess what, "you are wearing out your starter motor"...
The problem with this line of thought is that it ignores the fact that the ESS system is designed for constant use. This includes the engine (including nitrided bearing surfaces to eliminate galling), a special battery (designed for this use, normal batteries don’t last) and the starter (not your ‘normal’ starter motor). This logic is like saying “using your brakes wears them out”......


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You are correct...It does have wear and tear on the Starter Motor...Starter motors like any other component have a cyclic life...so, if you are in heavy traffic coming to a complete stop and the engine stops, guess what, "you are wearing out your starter motor"...
The starter motor is one component, the battery another, but all the moving parts of the engine are stressed in a restart. has any one done an oil-analysis comparison between two engines, each after, say, 3000 miles, where one has gone through stop-start hundreds of times and the other is not? Those oil analyses would show the wear differences. Has there been emissions tests comparing emissions during idle and the emissions resulting from those "instant" stop-start cycles?
 
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The starter motor is one component, the battery another, but all the moving parts of the engine are stressed in a restart. has any one done an oil-analysis comparison between two engines, each after, say, 3000 miles, where one has gone through stop-start hundreds of times and the other is not? Those oil analyses would show the wear differences. Has there been emissions tests comparing emissions during idle and the emissions resulting from those "instant" stop-start cycles?


Very well put. Everyone knows the hardest stress on an engine is starting it. There is no long term studies showing that this stupid ESS feature does not put any add’l stress on the engine and related components. Unfortunately us owners are the test group for this feature.

Those that don’t think start/stop is not hard on the engine or that the engine is designed to take that stress: come back in another 3-4 yrs and will see how well the engine stood up to this completely idiotic feature.



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The starter motor is one component, the battery another, but all the moving parts of the engine are stressed in a restart. has any one done an oil-analysis comparison between two engines, each after, say, 3000 miles, where one has gone through stop-start hundreds of times and the other is not? Those oil analyses would show the wear differences.
Doing it on the same vehicle with the same driving pattern would likely be the best comparison, would be interesting to see the results.

Has there been emissions tests comparing emissions during idle and the emissions resulting from those "instant" stop-start cycles?
I think one can simply derive from the fuel savings that ESS has less emissions provided your stops are long enough to save fuel. I believe about 7 seconds was the minimum.
 

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Doing it on the same vehicle with the same driving pattern would likely be the best comparison, would be interesting to see the results.

I think one can simply derive from the fuel savings that ESS has less emissions provided your stops are long enough to save fuel. I believe about 7 seconds was the minimum.
I doubt the 7 seconds figure. You may hear the starter go into action almost instantaneously, but I doubt the engine is back up to normal operating speed, temperature and pressure in less than 10.. maybe a lot more.

However without hard data to we're left with nothing more than thinly disguised political statements about better fuel economy and lower emissions.
 
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I doubt the 7 seconds figure. You may hear the starter go into action almost instantaneously, but I doubt the engine is back up to normal operating speed, temperature and pressure in less than 10.. maybe a lot more.

However without hard data to we're left with nothing more than thinly disguised political statements about better fuel economy and lower emissions.
The hard data is available for the fuel savings.
 

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The hard data is available for the fuel savings.
Where is this "hard data"? What is it based on? Stops at red lights of 1-2 minutes? Stoip signs at a few seconds?
 

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Engineering Explained really explains it perfectly. Watch the video and you can see how much fuel it saves using ESS versus just idling. Yes it will wear out the starter but saves you gas. New starter would cost more than the relative gas savings to me as I never have much traffic in my city.

 
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lol, I gather you haven't heard of google?

P.S. I'm not a fan of ESS, mine is almost always off.
Yeah, I heard of Google, and just a few other search sites as well. Aside from your wisecrack, you know one can find almost any "information" with a search, factual and some not.

Most of the search results turn out to be either marketing hype or political hype.
If you have actual independently developed data, which is not either, that will be worth reading.
 

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There are SAE and government agency tests that go into a good amount of detail. Your best bet on getting actual hard data.

There are others, auto-magazines, bloggers, etc that do less scientific, more example based tests but I would take those specific results with a few grains of salt.
 

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Very well put. Everyone knows the hardest stress on an engine is starting it. There is no long term studies showing that this stupid ESS feature does not put any add’l stress on the engine and related components. Unfortunately us owners are the test group for this feature.

Those that don’t think start/stop is not hard on the engine or that the engine is designed to take that stress: come back in another 3-4 yrs and will see how well the engine stood up to this completely idiotic feature.



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ESS systems have been on the Cherokee since the 2015 model year.

ESS systems have been in use much longer than that. IIRC, the first systems were designed by Fiat, and used in Europe.
 
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