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Gurus - care to comment on stop-start disable?

35K views 75 replies 36 participants last post by  1 Lucky Texan 
#1 ·
I ran across this;

I was a service advisor at subaru. the easiest way to permanently disable the start/stop system without any warning lights is to have a genuine towbar fitted, and dig out the magnet from the inside of the 7 pin plug. this way a signal is being sent to the car saying you might be towing, which disables the auto start stop system without any warning lights or other symptoms. I suspect it will probably work the same on other models. Your welcome everyone.
555
which indicates there could be a 'simple' fix for disabling stop-start by 'hacking' the trailer tow wiring harness.
 
#5 ·
Yesterday I drove 52 miles one way to court and the first 1/3 was normal traffic but the last part was bumper to bumper for 30+ miles. Took me nearly 2:30 hours and that doesn't include the return trip.

Just an educated guess but I bet I did the start stop thing well over 100 times, one way, not including stoplights.

Carl posted the costs of the starter and battery for some current model and IIRC, it was close to $800, if not more, for the starter and battery for the start stop components.

I much prefer to keep the engine running, AC working in 100 stop trips not including the high heat too.

I'm fearful that replacing the expensive battery and starter, just like walnut blasting of the valves, is going to be considered a wear and tear/maintenance item, all in the name of mpg, emissions and efficiency.
 
#7 ·
There might be a simple defeat via disconnecting the hood switch.

My dad's 16 Rio5 had stop/start. There was a button to disable after start-up, but didn't want to press it every time.

Unplugging the hood switch would keep it from stopping (assuming someone was under the hood working).

Not sure if Subaru has a "smart" switch or uses the same switch for the remote-start, but it might be worth looking into.
 
#8 ·
My MY'17 Outback does not have the Stop/Start feature so I have not tried this myself, but I know it works on other car makes. When you come to a stop, put it in Manual mode. I believe this should disable the Stop/Start. I appreciate someone trying this on an Outback and letting me know if this is true for a Subaru as well. Thanks
 
#10 ·
Those are very interesting numbers worthy of checking into although I also use plastic straws and plastic bags so I'm not going nuts over the green stuff.

The start stop isn't so much about the benefits to an individual but rather as cumulative for all drivers to parlay that into barrels of crude saved.

If marketing said I'd save 10 gallons a year by having start stop I wouldn't consider it a selling point. Same with DI relative to maintenance costs likely to be incurred down the road.
 
#11 ·
I think the jury may still be out as to savings - suppose the batteries are heavier and/or trickier to produce? are the starters heavier? that means not only is the car itself sacrificing some economy to haul them around, but so are trains/trucks/ships w'ever.

needs a true cradle-to-grave examination. Also throw in the added complexity of 'one more system to break', etc. Even people's habit of 'homeostasis' with fuel costs - it's why you see folks trade up and down in car size with fuel prices.
 
#16 ·
I'm sure those new-fangled electric self-starters were welcomed with suspicion by some a century ago, too.

I'm somewhat skeptical about the overall practicality of start-stop systems. Are the relatively modest savings in fuel worth the added complexity and mechanical wear and tear involved? How long does the engine have to be shut off before the energy savings exceed the energy needed to restart it?

I do recognize that using a system designed to operate that way is one thing, and different from trying to simulate that by abusing a system that's not designed to operate that way by shutting it off then restarting it again after a few seconds again and again. I will admit that I usually shut the ignition off if I know I'll be waiting for several minutes, like when stopped for a train crossing.
 
#17 ·
I have a question. If you are driving with Eyesight and the car stops by itself because the car in front stops, will the car use the Stop/Start "feature"? Also, if I stop the car by myself, not following another car for instance and I use the electronic parking brake (which I often do) will the stop/start activate?
 
#18 ·
My experience with start/stop technology is only with my wife's Prius, where it's designed in as an integral part of the hybrid synergy system.

And more importantly, it bump starts the gas engine using the car's inertia, the 250 V traction motor, or some combination of the two. Can't say I've ever heard the gas engine's cranking motor operate, but I suppose there has to be one there if the traction batteries are at their minimum level (and note Toyota software limits the NiMH battery cycle to the 30-70% range, so there's most always sill some energy there at "minimum").

Regarding more conventional gas cars using this technology, the jury's out on that one as far as I'm concerned. I wouldn't go out of my way to avoid this technology, nor would I try to get something that had it. But in any case, it's probably going to be unavoidable at some point with any gas engine car.
 
#20 ·
My Subaru does not have this feature, and I admit that a few years ago I was skeptical of start-stop systems. But I drove a friend's Audi Q5 recently and it is seamless. Similarly I had a Golf in Iceland last summer with the feature, and it was a stick shift. This was also seamless, as it also has a hill hold feature on the manual transmission. It literally took me 10 minutes in city traffic (Reykjavik) to get to the point where I didn't notice it anymore.

Road and Track would argue the system has benefits: https://www.roadandtrack.com/new-ca...303/automatic-start-stop-useful-fuel-savings/

The system is a secondary one to the regular starter and won't impact the main cold start system over the life of the car.

Europeans have been using start/stop for 20 years to reduce pollution in cities. The Golf is a fuel miser for sure, but given my Icelandic Golf was averaging 3.8L/100km (or about 61mpg) with the 1.5L TSI Engine in mixed driving, I would say the system saves fuel, at least on the city cycle.
 
#21 ·
Just my .02 that will mean nothing to anyone since it's close to only me specifically. But my dad is a typical diehard, old school man who always cussed the start/stop technology. He recently gave in and bought a new Malibu (hasn't had a non-GM vehicle in 15 years, never had a foreign car) and now raves about how great the car is on gas mileage and can't even notice the start/stop crap. Again probably doesn't hold much weight to strangers on the internet, but all the proof I need!
 
#22 ·
Fuel is such a small part of wning a car. It is amazing there is so much discussion on fuel economy. It takes energy to move a objet and you can only squeeze so much out of a fuel molecule calibrated in ton miles. Therefore auuto manufactures are sacrificing important durability factor in the name of better fuel mileage (CAFE). Subaru has one to thinner crappy windshied and non performin batterie. Of what value is a tenth of a mile to the gallon at the cot of a $900 windshield and a non dependeable but lighter $120 battery. You replace those items with better qualityfor reliabilty and minescaul mileage saving have long disapeared. The spare tire is only good for short distance in a urban are. How good do you feel about a cheap battery non functional off pavement spare and a car held togehter with lighter plastic push pins. Then you want to put a bike, canoe or sky box on top and you have to trash the factory cross rails for much more expensive aftermarket rails. In the meantime you have added a decent skid plate as your lost the plastic under cover due to pushpin failure when you came into contact with a parking bumper in the safeway parking lot. So where is the savings in fuel in the desired use of the vehicle? I would like to buy a vehicle to meet my needs at the time of purchase.
 
#23 ·
Fuel is such a small part of wning a car. It is amazing there is so much discussion on fuel economy.
I disagree. The cost of fuel is a significant part of operating a car.

If you get 27 miles per gallon and gasoline costs $2.70 per gallon, that means fuel cost is $0.10 (ten cents) per mile. If you drive the car 150,000 miles, you've used $15,000 in fuel. If, instead of 27 mi/gal, you managed to get 30, the cost is 9 cents/mile, saving 10% in fuel and $1500 over the lifetime. The only single item likely to be higher than fuel costs is depreciation; if your new $30,000 car declined in value to $4,000 after 130,000 miles, that's 20 cents per mile.

What else? Tires... say a $600 set of tires lasts 40,000 miles; that's 1.5 cents per mile. $60 oil changes every 6,000 miles... 1 cent per mile (1.5 c per mi if they cost $90). That $450 service in addition to the oil every 30,000 miles? 1.5 cents. Batteries? Say $200 every 50,000 miles... 0.4 cents (less than half a cent) per mile; if you find a good battery on sale for $90 that lasts 45,000 miles, it's $0.002 (two-tenths of a cent) per mile. If you add up all routine maintenance items, you will struggle to reach the routine cost of fuel unless something is wrong, like the car eats tires or consumes a quart of motor oil every 1000 miles (or you abuse it so that things are constantly breaking, in which case all bets are off).

For routine stuff, fuel costs loom quite large. Some of the other stuff you speculate about, like skid plates, replacement roof racks and the like aren't needed or wanted by probably 99% of owners. If you feel these things are necessary, you may be looking at the wrong vehicle. But, that said, you can buy quite a bit of customization stuff for $1500.
 
#26 ·
Having never driven a car with stop/start, I have a basic question: how soon after the vehicle stops does the engine shut off? Is it instant, or does it for example give you enough time to stop at a Stop sign then proceed without shutting down the engine?

To me, it might make sense if the engine shut off when the vehicle is idle for maybe 10 seconds (when you're stopped in traffic or waiting at a light), but not if you're just stopping for a second or two.
 
#31 ·
if you click 'show more' you'll read this info he also posted;

AutoExpert TV
Published on Mar 9, 2019
Argonne National Labs report: https://publications.anl.gov/anlpubs/...

Engineering Explained’s ‘7-second’ video: https://www.youtube.com/watch?v=dFImH...

I get three or four of these comments a week, from dickheads just like this:

"Watch Engineering Explained channels video that runs the actual math on this topic. You’ll find actual science completely contradicts the s*** you hear spewing from this dissertation." - NorthernChev

Engineering Explained. I really like Jason Fenske’s channel - Engineering Explained. I’ve watched dozens of his reports. He’s very successful, and he deserves to be. He tackles some hardcore topics and makes them pretty digestible for the mainstream.

But on the 5th of September last year, Jason put up a video called ‘Americans have no idea how much fuel idling uses’.

Jason referenced a 14 year old study in the SAE for most of the data, and the mathematics is absolutely on the money - but I respectfully believe he’s sending the wrong overall message. Profoundly wrong. And here’s why.

Basically, it would be easy to watch that report on Engineering Explained and infer that it’s a good idea to shut your engine down if you look like being stopped for more than seven seconds.

Because you are (quote-unquote) “wasting fuel” beyond that point, according to Mr Fenske. Which is synonymous in most people’s minds with ‘wasting money’.

But I’d suggest this conclusion a viewer might draw - about seven seconds being the ‘go/no-go’ threshhold for shutting down - is simply bullshit - using Professor Harry G Frankfurt’s definition of that term.
And this is not my opinion - I’m using research and data from Argonne National Laboratories in Illinois - one of the US’s premier engineering research centres.

You’ve heard of the Manhattan Project right? Big win for our team in August 1945. Argonne did that.

In April 2015, the dudes at Argonne published a report with the catchy title ‘Stop and Restart Effects on Modern Vehicle Starting System Components - Longevity and Economic Factors’. Miracle cure for insomnia, right there, for many people. But not me, or you.

Scientifically robust. They conscripted the technical input from six automakers, plus Denso and Johnson Controls, the SAE and Oak Ridge National Laboratory. It’s kinda the ‘works burger’ of engineering intellectual grunt on this issue.

It’s 20 pages of heavy going - a full economic analysis of the potential cost implications) of choosing to manually shut down your engine in traffic.

“...a minimum shutdown duration of approximately one minute for six or fewer additional starts per day results in economic savings due to a reduction in idling fuel cost.” - Argonne National Lab.

This is a hardcore academic analysis which basically took all the technical factors into account - like starter and battery design life - and corrected the fuel saving for fuel used on restart, the wear effects on starter motors, the battery life implications of more frequent restarts and additional charge depletion, etc.

And they did it for a projected 10-year period of the vehicle’s life.
What they found was that if you shut down and restart often, like 12-20 times a day, and if the shut down duration is short, like, less than 2-3 minutes, then doing this will actually cost you money.

If you shut down fewer times - like, six or eight times a day - for more than about five minutes per shutdown - you’ll save money.

But in either case, the amount is completely trivial, in the context of household budgets. Maximum possible saving for a two-litre engine: $400 (US dollars) over 10 years. To do that, you need to be shut down for eight or nine minutes at a time. That’s 11 cents a day (US).

Worst case, two-litre engine: 18-20 re-starts daily, each for a minute or two … that’s going to cost you an additional $600 (US dollars) in accelerated battery death and starter wear. Call it 16 cents a day (US).

That’s a loose definition of ‘beneficial’, in my view. I’d suggest that there’s no other domain in human life where people would devote any attention span at all to an activity that will impact their lives between +11 and -16 cents per day. The concept is absurd.
 
#33 ·
Well, no. The only reason start/stop is becoming common on newer vehicles is because the manufacturers have to meet CAFE standards and this technology is something they all know how to do.
It bumps the EPA numbers 1-2 mpg or so, the cost is passed on to the consumer, and they go on their way. It has absolutely nothing to do with a substantial reduction that couldn’t be achieved in another, better and realistic, way. This one is totally at the drivers expense, in initial cost, in obnoxious engine behavior, and in additional stuff to break.

I remember on line arguing with a guy that drove a large suv and opined that I should be happy to operate stop start on my small, fuel efficient vehicle in order to “save” something so, MOL, he could drive the hog. I suggested he should buy a Prius and dump that huge gas hog before lecturing me. IMO each person is responsible for reducing their carbon production and fuel use. That’s sensible. Start stop is an incredibly stupid and obnoxious way to do it. Buy a smaller vehicle, drive it less. Or whatever works best for you.


Sent from my iPad using Tapatalk
 
#34 ·
One huge downside (and maybe somebody can provide more info), is that the A/C must be non-existent or less efficient when the engine is off. The same goes with the heater. In Sacramento summers, a less efficient A/C is not an option for me. In Tahoe winters, a non-working heater is not an option. So, I should be able to use the stop-start feature for only about 90 days out of the year, when weather is not at the extremes.
 
#36 ·
Automakers have addressed this issue. I spent a week in Atlanta last summer with a rented Ford Expedition. Interior temp is monitored as part of the auto temp control and engine would start back up when temps went above the desired setting.

Sad to see folks ranting about a technology with no understanding how it works or any real world experience.
 
#44 ·
I'm no "expert" and have not done any in depth studies, but I do have a few years under my belt. I can only assume that 100's of starting and stopping the engine can't have some effect on the engine, and probably not a good one. Lubricating issues certainly come to mind. Wear and tear also certainly come to mind. On a global scale quite a bit of fuel is saved, on a personal scale it is almost insignificant, and has to be held up against any repairs that may result from it. IMHO, I'll pass on it.
 
#60 ·
That reason is still there for some of us. My Corvette is a pleasure to drive as is our Camaro. The Caddy CTS was a fantastic car to drive but just a tad too small. My OB was not a pleasure to drive nor is my wife's Forester.

"A pleasure to drive" is still a reason to buy a car...also a reason to get rid of a car that provides little pleasure.
 
#59 ·
I would be less annoyed with the whole darn thing, if Subaru had put in one of the belt or similar systems, where they don't use the cold-start starter, I believe this is what the BMW, and quite a few others now have.
I've seen vids of some of those starting, they're butter-smooth, it's got to be that small starter, engaging that ring-gear and spinning up the flywheel, to-start, something about that process.
The other systems spin via the flywheel, which admittedly is just the other side of the engine, effectively, but they sure look smooth (not like how my 2020 Limited XT re-starts anyway).
I get an occasional smooth-start, I'd say 1/4, but the other 3 are pretty abrupt, along those lines, I think I described it previously as if the car was "hit by a light gust of wind", the kind that sort of rocks the car.
It's work-able, but annoying, if you watch some others. In particular, I hate the instant-restart stuff, when the heater is running and you pull up to a stoplight, it shuts down in maybe 5 seconds, and then restarts, maybe 5 seconds later, so it can keep the heater going. I'm a s/w (and h/w boundary) guy, and I'd be sort of embarrassed if my design worked this way, it's 2020, not 2002, or 1982... :oops:?;)
 
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