Subaru Outback Forums banner

How do you REALLY feel about the Start/Stop System?

  • It is great, I love it!

    Votes: 86 13.1%
  • I don't care, indifferent.

    Votes: 124 18.9%
  • I don't like it but I can live with it.

    Votes: 158 24.1%
  • I hate it, I wish I could disable it permanently.

    Votes: 287 43.8%

  • Total voters
    655
1481 - 1500 of 1530 Posts

·
Premium Member
2001 VDC/SC One of a Kind
Joined
·
13,345 Posts
The stop start systems used by all manufacturers are not aimed at saving fuel. It's meant to reduce tailpipe emissions. If the the engine isn't running there's nothing coming out the pipe(s). And I've not been in any car with the system that didn't have the same type of shutter. The engine is started and immediately after the transmission applies the forward gear.

Fuel consumption won't go down. For the moment the engine and trans are started back up the fuel is slightly enriched. In stop and go traffic it would seem to me that the vehicle would use slightly more fuel with constant starts than if it remained running. If fuel was measured against engine run time and not miles driven, you'd probably see minute higher consumption in the start/stop usage over keeping it off, but this would also depends on the circumstances of the drive; i.e. idle time, AC on or off, amount of stop and go traffic, etc.

A car's fuel consumption is based on how you drive it while cruising, the overall "health" of the drivetrain and the grade of gasoline in the tank. (My Impreza and Forester both get higher mpg than the emissions labels listed.)

Everyone say Thank You to CARB and their need to imagine things that may give people a sense of making a change in the environment while giving the auto manufacturers some points toward carbon footprint rebates. It was lobbied as a method to reduce emissions and legislations followed based on the "climate change" agenda which has been a political driver for some time.

Kinda like the electric cars. They are not totally zero emission vehicles when you consider how the electricity gets applied to the grid for the cars to have charged batteries. Coal, oil and natural gas all put out HCs and NOx. Atomic energy is clean but there's still no way to dispose of atomic waste that will satisfy everyone, politics. So there's some give because the overall emission output is lowered when compared to a standard combustion engine. (And so far, I prefer a Tesla over other totally electric cars. Much quicker, smarter and comfortable. (And I have been in the Bimmer; thanks for asking.)
 

·
Registered
Joined
·
3 Posts
Honestly, I absolutely hated that auto stop start feature didn’t even take me a week of driving with it. Then they had to bury the on off switch way down in the menu. Since summer is here I don’t think I will have an immediate need for the rear window defroster. So, shame on me, I pulled out Fuse 33 (to save wear & tear on the defrost and side mirror heater wiring) in the main engine compartment, set the defrost to always on, and simply use the rear defrost switch to disable the auto on off starting function. I live in the suburbs. Stop signs, traffic lights every block. If I dared cruise through one of those stop signs, that’ll be the one that gets me the ticket. For me, it’s quite comforting to see the AVH kick in. Maybe I will find I need the fuse this winter, I can simply pop it back in and leave the defrost set to always on. Then again, as a professional electrical engineer, I may find a work around:) (Manual cab mounted switch for temp enable of R.DEF relay?)
Fuse Box in Engine Compartment: 2020 Owner Manual Page 530, Fuse Panel 33 R.DEF
This is a really great idea. I have posted that the start/stop is not much of an issue as I have a very light foot on the brake and the engine stop is almost never activated. My wife finds the start/stop activated very often. The use of the rear defrost switch as a one touch deactivate is a great work around. I live in Minnesota 50 miles North of Mpls. and even in this cold Winter climate I use the rear defrost very, very seldom. I will use your excellent idea and I really doubt that I will ever put the fuse back in place. Thanks a lot.......
 

·
Registered
2019 Subaru Forester Premium, Crystal Black Silica, Pkg 15
Joined
·
1,440 Posts
I've been turning off the AutoStop in my 2019 Forester. I at least have a physical button nearby. I wouldn't mind it so much if it wasn't so jarring and I like driving with AVH enabled so I don't have to hold the brake down.

How does the fuse change things? Does it basically run the defroster all the time but doesn't actually complete the circuit since you've pulled the fuse?

I've noticed in winter my AutoStop very rarely actually enables, and if it does, it's once or twice a drive. My commute is around 10 miles, with about 50% very urban city and 50% highway, then a quick mile or two through suburban streets - but same complaint as above, I hate when it kicks in at a stop sign.

My sister-in-law drives a relatively new Toyota Highlander, and the AutoStop is so smooth in that thing I didn't even realize it was there. Perhaps it's a limitation of the torque from the Boxer engine, but dunno.
 

·
Registered
2020 Outback Limited
Joined
·
157 Posts
My sister-in-law drives a relatively new Toyota Highlander, and the AutoStop is so smooth in that thing I didn't even realize it was there. Perhaps it's a limitation of the torque from the Boxer engine, but dunno.
Is it the hybrid? :)

I've had two turbo BMWs with ASS, and they were just as jarring (if not more so) than my 2.5 Outback when it fired back up. I guess since I've lived with ASS for last six years on previous cars it doesn't really bother me on the Outback.
 

·
Registered
2019 Subaru Forester Premium, Crystal Black Silica, Pkg 15
Joined
·
1,440 Posts
@Chupacabra -

No, it's not the hybrid. It's the V6 and it's buttery smooth. I like that car a lot, and in hindsight if I knew about the mechanical advantages Toyota had compared to the Honda Pilot we'd purchased, I would have been more emphatic about her pursuing a Highlander.

From what I watched on some YouTube reviews, it sounded like the XT for some reason was smoother in the restart. I have no idea why this could possibly be, but I know that at least 3 YouTube channels mentioned it, taken at face value of course.

I did Test Drive the Crosstrek PHEV not too long ago and that was a great experience, but too small of a vehicle for my preferences. If Subaru offered a PHEV Forester or Outback I would be all over that in a second. I love the direction Toyota's gone with their eAWD system and I'm really happy to see it being rolled out to their whole fleet.
 

·
Registered
2020 Outback Limited
Joined
·
157 Posts
From what I watched on some YouTube reviews, it sounded like the XT for some reason was smoother in the restart. I have no idea why this could possibly be, but I know that at least 3 YouTube channels mentioned it, taken at face value of course.
The only reason I can think of why the XT might be a little smoother is that I believe the 2.4T has a lower compression ratio than the 2.5, so potentially easier to spin it up again. But I'm just spitballing here. I'd say that my 2.5 Outback is already a little bit smoother when it starts back up then my two previous BMWs, which were 2.0 turbos. I really don't even notice it much, again because I've been driving ASS-equipped cars for six years prior to this one.
 

·
Registered
2020 Subaru Outback
Joined
·
17 Posts
I've been turning off the AutoStop in my 2019 Forester. I at least have a physical button nearby. I wouldn't mind it so much if it wasn't so jarring and I like driving with AVH enabled so I don't have to hold the brake down.

How does the fuse change things? Does it basically run the defroster all the time but doesn't actually complete the circuit since you've pulled the fuse?

I've noticed in winter my AutoStop very rarely actually enables, and if it does, it's once or twice a drive. My commute is around 10 miles, with about 50% very urban city and 50% highway, then a quick mile or two through suburban streets - but same complaint as above, I hate when it kicks in at a stop sign.

My sister-in-law drives a relatively new Toyota Highlander, and the AutoStop is so smooth in that thing I didn't even realize it was there. Perhaps it's a limitation of the torque from the Boxer engine, but dunno.
Using the Rear Def is a “Poor Man’s” workaround for the simple button you already have. Removing the fuse simply prevents electrical current from circulating in the primary circuit. Unfortunately that disables the “real life” action of the Rear Def but is a trade off I am willing to accept for the simple one touch disable of the Auto Start/Stop.
Regards, have a nice day.
 

·
Registered
2016 2.5i
Joined
·
1,791 Posts
Yeah I am pretty sure Auto Start Stop is really about emissions control and not for fuel savings.
Can you explain the difference? Isn't one causing the other, especially in the case of auto start stop? If you only save 0.001% of fuel, you'll also save roughly 0.001% in emissions, right? Or not?
Or, in other words: if the fuel savings are insignificant, the emissions savings will be insignificant as well.
 

·
Registered
2016 2.5i
Joined
·
1,791 Posts
This might amuse you: You're the third electrical engineer on this board that has talked about devising a workaround. If you can pull off this task, you will be the hero.

So far nobody has divulged if they have succeeded in producing such a device for their own cars, but many of us non-electrical engineers are chomping at the bit for someone to either make plans available, or sell a kit, or a device we can install at our own risk. There has also been talk about looking at the source code, but nobody has been able to obtain it (that I know of).

We have been pulling fuses and relays to be able to use front and rear defrosters without using drain. In addition to the rear defrost fuse, I have pulled the two relays: Front wiper deicer, and mirror heater relay. There is also a rear defrogger relay, but I have left that in so that if I put the fuse back in, the defroster will work but not the wiper deicer and mirror heater (I'm in Hawaii). I also pulled the three PTC relays because I don't need electrical heaters for the HVAC.

View attachment 484482
I need to get going on this.
What happens if you pull the rear defogger relay only? Not enough to avoid current draw?
 

·
Registered
Joined
·
2,439 Posts
I need to get going on this.
What happens if you pull the rear defogger relay only? Not enough to avoid current draw?
I wish I really knew - not sure how to measure the current draw correctly with pulling fuses and relays. I have a regular multimeter. A friend has one of those fluke non-contact things that goes around wires but I don't know how to use it.
 

·
Registered
2020 Subaru Outback
Joined
·
17 Posts
I need to get going on this.
What happens if you pull the rear defogger relay only? Not enough to avoid current draw?
The vehicle electronics system isn’t capable of switching the relatively high current needed to operate the defogger element. The electronics can energize the relatively low current requirements of a relay coil. The relay contact tips can handle the much higher load current. I prefer not to interfere with the actual computer controlled output circuit therefore pull the fuse in the main circuit. It’s kind of an electronics thing with differing terminologies for switching such as “sinking” or “sourcing” as well as a potentially “mixed bag” of results.
Regards!
 

·
Registered
2020 Subaru Outback
Joined
·
17 Posts
I wish I really knew - not sure how to measure the current draw correctly with pulling fuses and relays. I have a regular multimeter. A friend has one of those fluke non-contact things that goes around wires but I don't know how to use it.
My Fluke is rated (fuse protected) to 10 amps if I recall. Normally I would switch the leads to measure current, set the Fluke scale to measure current, pull the fuse from the circuit I wanted to measure current in, place 1 lead on one side of the fuse holder and the other lead on the other side of the fuse holder. The Fluke then bridges the circuit gap with a very low resistance internal shunt. Internally the Fluke measures the voltage drop across that internal shunt and displays it as amps. However for the defogger, the fuse is rated at 25 amp, much greater than my Fluke’s rating.
See this Fluke article for measuring current.
The non circuit clamp you seem to be referring to is known as a Hall Effect clamp. You would need to find the power wire in the wiring harness and clamp it around that single wire. Since current flowing through a conductor creates a surrounding magnetic field, the current can be derived from the strength of that field. This link is a good explanation of how a clamp on ammeter works.

Hope that helps,
Regards
 

·
Registered
Joined
·
2,439 Posts
The non circuit clamp you seem to be referring to is known as a Hall Effect clamp. You would need to find the power wire in the wiring harness and clamp it around that single wire. Since current flowing through a conductor creates a surrounding magnetic field, the current can be derived from the strength of that field. This link is a good explanation of how a clamp on ammeter works.
Yes that's it! I don't to mess with singling wires out of my wiring harness - the clamp thing is pretty big. I'm ok with just pulling fuses and relays for stuff I don't use without knowing the actual current draw. It wouldn't change my situation.
 

·
SubaruOutback.org Founder
2018 Outbacks, Grey Premium & Silver Limited
Joined
·
4,806 Posts
Can you explain the difference? Isn't one causing the other, especially in the case of auto start stop? If you only save 0.001% of fuel, you'll also save roughly 0.001% in emissions, right? Or not?
Or, in other words: if the fuel savings are insignificant, the emissions savings will be insignificant as well.
I think the issue here is how the system is presented to the customer as a benefit. In reality most people see this as an unnecessary contrivance that the majority simply want nothing to do with but are forced to contend with.

Subaru though wants to sell this as a fuel saving benefit when in reality it contributes little to that effort. In reality Subaru mandated the usage of the system so to better position themselves to comply with the ever increasing emission standards.

So it is a benefit to Subaru but an annoyance to their customers but Subaru wants the customer to perceive it as a positive while further annoying the customer by making it frustrating to disable.
 

·
SubaruOutback.org Founder
2018 Outbacks, Grey Premium & Silver Limited
Joined
·
4,806 Posts
All of this discontent (me included) would go away if Subaru would simply do a software fix which makes ASS easy to turn off, and stays off until the driver wants it back on. Can’t be hard. Why don’t they?
I am inclined to believe that if it were easy to disable or simply turn off more frequently, that the environmentalist regulators would somehow penalize Subaru on their emissions ratings which is what Subaru wants to avoid and thus why they forced the usage of this system in the first place.
 

·
Registered
2020 Subaru Outback
Joined
·
17 Posts
I think the issue here is how the system is presented to the customer as a benefit. In reality most people see this as an unnecessary contrivance that the majority simply want nothing to do with but are forced to contend with.

Subaru though wants to sell this as a fuel saving benefit when in reality it contributes little to that effort. In reality Subaru mandated the usage of the system so to better position themselves to comply with the ever increasing emission standards.

So it is a benefit to Subaru but an annoyance to their customers but Subaru wants the customer to perceive it as a positive while further annoying the customer by making it frustrating to disable.
I couldn’t agree more. The entire notion of the automatic stop/start still has too many fatal flaws. Auto batteries can fool a simple “voltage is OK” therefore the battery is OK. Real battery testers check the battery under load. It’s pretty common knowledge that batteries have a finite number of charge discharge cycles (forgive me but technical reasons require much more than a sentence or two). The auto start/stop will without doubt reduce overall battery life. Imagine a “weak” battery that still puts out 12 VDC but doesn’t retain a full charge. You might be in a stop and go traffic situation with the automatic start/stop system functioning then boom, not enough charge remaining in the battery to restart the engine.
Here is an interesting “test” done on a short trip with start/stop and without. The net result was the battery using the start/stop didn’t fully regain its charge.
Don’t get too put off with the term Coulomb. 1C equals 1Amp of current (simply measured in the number of electrons) passing through a given point in 1 second. We tend to think of car batteries in Amp/Hrs.
Anyway, in depth scientific explanations can be found to as deep as you care to go.
For me, I intensely dislike the Auto Start/Stop function. I can visualize too many pitfalls
 

·
Registered
2018 Touring 3.6R
Joined
·
338 Posts
I am inclined to believe that if it were easy to disable or simply turn off more frequently, that the environmentalist regulators would somehow penalize Subaru on their emissions ratings which is what Subaru wants to avoid and thus why they forced the usage of this system in the first place.
I don’t think so. My last car, a 2014 BMW, allowed the ASS to be easily turned off and on, and it stayed in that position until I changed it. Subaru could do this too. Why don’t they?
 

·
Registered
2020 Subaru Outback
Joined
·
17 Posts
I don’t think so. My last car, a 2014 BMW, allowed the ASS to be easily turned off and on, and it stayed in that position until I changed it. Subaru could do this too. Why don’t they?
Possibly being clever to save the cost of a push button. Engineers aren’t always practical. When we first started using color type touch screen HMIs (Human Machine Interface), some engineers felt “obligated” to use every color available on a simple screen. It’s still a standing joke amongst us old timers that grew up with analog meters, rheostats, relays, switches, etc.😆
And don’t get me started on bearings and oil. I have seen too many real life and extremely costly examples of premature bearing failures on electric motors because of frequent motor start stops. I am talking about motors with 6” or greater diameter bearing journals riding babbitt bearings. But the same can be inferred to nearly any bearing where the lubricant is “squeezed out” in the stopped mode.
 
1481 - 1500 of 1530 Posts
Top