How much fuel does ASS (Auto Start Stop) save?

[Jeep Wick]

That happens with another EPA item for manuals, at least in the V8 performance cars. Around 1996 or so, they started installing a solenoid in the transmission that would “lock out” 2nd/3rd gear, forcing you to shift from 1rst to 4th. If you were at a certain speed and certain throttle position, it would activate. All in the name of emissions.

So if you’re accelerating from a stop light and this solenoid kicks in, you’re fighting with the shifter trying to get it into second gear. That little bit of a delay getting into 4th gear is dangerous as hell. The first time it happened to me, I was almost rear ended. I thought my shifter had broken, then was told about the solenoid.

I promptly disabled it permanently. It’s a manual FFS.

I remember when they added this to the Camaro and Firebird. Eventually someone figured out a bypass.

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[Ratbert]

John:

With complete respect intended to this thread and its thoughts that you got the ball rolling on, I'm sure you agree that we can throw all the metrics of fuel savings in the trash if the system doesn't engage at stop lights for owners willing to not disengage it.

Forgetting for a moment those who have implemented either tech, hacks and expressly pressed the button to turn the system off, I am curious to know just how many JL owners find the ESS system continues to work after driving off the dealer lot, and if so for how long.

I know that I am not alone, and of course my infrequent use/short trips driving plays into this, that there is no way my ESS would engage were I not also trickle charging the dual factory batteries while the vehicle is parked.

To this point, an EPA test that doesn't track the reliability of such a system continuing to engage years into ownership, but rather tests the vehicle when new, once, like crash testing, is not a standard, at least in dual factory battery JL implementations, that accurately reflects mileage improvements of vehicle life.

It's almost always disabled in my rig (thanks Tazer), but it does serve as a decent indicator of issues with that part of our electrical system. Without it I wouldn't have known that my IBS was severely questionable.

The video highlighted the massive disparity between perceptions of when it improves mileage and when it actually improves mileage.

Engineering Explained is exceptional at looking at things from scientifically measurable / calculate-able perspective. Feel free to expand on it with additional perspectives if you desire. That's what these forums are about.

 

[driventoadventure]

John:

With complete respect intended to this thread and its thoughts that you got the ball rolling on, I'm sure you agree that we can throw all the metrics of fuel savings in the trash if the system doesn't engage at stop lights for owners willing to not disengage it.

Forgetting for a moment those who have implemented either tech, hacks and expressly pressed the button to turn the system off, I am curious to know just how many JL owners find the ESS system continues to work after driving off the dealer lot, and if so for how long.

I know that I am not alone, and of course my infrequent use/short trips driving plays into this, that there is no way my ESS would engage were I not also trickle charging the dual factory batteries while the vehicle is parked.

To this point, an EPA test that doesn't track the reliability of such a system continuing to engage years into ownership, but rather tests the vehicle when new, once, like crash testing, is not a standard, at least in dual factory battery JL implementations, that accurately reflects mileage improvements of vehicle life.

For what it is worth, even though I keep my Jeep on a charger when it's at home, my ESS basically never works because it's always saying "Charging" even after replacing the aux battery (main battery is next for test/replacement). I personally find it incredibly irritating, because when it (rarely) works I find both noticeable fuel economy improvement, and I very much love the quiet of not having my Diesel running when I am stopped somewhere (especially if I am going through a drive-through or similar.)

 

[Dusty Dude]

I remember when they added this to the Camaro and Firebird. Eventually someone figured out a bypass.

On my Challenger, I disconnected the solenoid and installed a “load” resistor that mimicked the solenoid. The computer throws a code if the solenoid is just disconnected. Thankfully it was external to the transmission.

The Camaros and Firebirds had to do the same thing to avoid throwing a code.

 

[Lapis]

My wife's Subaru has a meter that shows (estimates I'm sure) how much gas is saved by the ESS system. It's usually around 0.25gal/tank. So a little under 2% fuel savings.

 

[THAW]

Ok this is my last post for this topic.

For what it's worth, I've gotten some good laughs from your posts and find preachy moral posturing on internet forums mostly cringey.

Also, nice work on the storage box

 

[4x4 Mule]

EPA has stop start in the crosshairs: “Start/stop technology: where your car dies at every red light so companies get a climate participation trophy. EPA approved it, and everyone hates it, so we’re fixing it.

 

[Tank the Jeep]

In his right hand how much fuel a small 4 cylinder engine uses idling for 3.6 minutes. In his left hand, how much fuel is used to start that same engine. Just cause I’m a helper.

That’s all well and good, but the real question is… What happened to his arms? Those thing look like they belong to a 10 year old girl. Seriously, I want to snap that pencil neck. I refuse to respect someones opinion if they wear a child’s t-shirt.

 

[Terrymo]

That’s all well and good, but the real question is… What happened to his arms? Those thing look like they belong to a 10 year old girl. Seriously, I want to snap that pencil neck. I refuse to respect someones opinion if they wear a child’s t-shirt.

It’s Size Schmedium

 

[AlgUSF]

EPA has stop start in the crosshairs: “Start/stop technology: where your car dies at every red light so companies get a climate participation trophy. EPA approved it, and everyone hates it, so we’re fixing it.

I wonder if Jeep will provide a complimentary reflash for those of us who are stuck with (A.S.S. Auto Stop Start)?

Maybe the EPA can make it a mandatory safety recall.

 

[zouch]

i am skeptical that the ESS system actually costs you fuel economy; would love to see your tests.

the Automatic Climate Control system turns the engine back on when the ACC needs it to maintain your target temp if you're using the Automatic setting. if yours isn't doing this, something's wrong.

you *can* permanently disable the ESS; there are several aftermarket solutions, or you could do it with one of your Hood Switches. lot's of info here about it.

I hate the ESS. I turn it off every time I start it. I found I actually get a bit better gas mileage. And I hate that the AC and heat don't maintain their temp with ESS on - it's hot as hades in the summer down South, and the last thing I want is no AC. If I could disable the ESS permanently, I would.

 

[zouch]

i'd love to see the same testing done for a diesel; i'm not assuming that idling consumption rates are the same between Gas and Diesel engines.

It's a bit surprising how much it saves. City driving, of course. And he doesn't take additional wear into consideration.

 

[LVLAaron]

I have a Nissan Frontier - It gives stats on this. 20k miles. It says it's saved 7 liters. Meh.

 

[BadCompany]

OK, So is it the general consensus that the ASS option is not worth using?

 

[Oakridge88]

I hope I saved enough to pay for the kit to cut out that stupid system!

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