I just got a bmw and coming from a Jeep the most interesting thing is the auto start stop feature

I just got a bmw and coming from a Jeep the most interesting thing is the auto start stop feature.
I fucking hate it (especially when power steering suddenly dies at stops) but if I did have it on how much fuel will I be saving?

Pretty much nothing and causing extra wear in the long term.

It's for cheating the MPG tests.

5th gear did a test and it actually saves quite a bit of fuel.

That's Audi, not bmw

That's only if you stop

It's like everyone was speeding, and VAG was the only guy to get pulled over.

The starters are built for start/stop tho
The engine only stops at a certain point where its easiest to start up again. Still annoying but it works

[citation needed]

i got a loaner car BMW 330i and having the engine turn off at every light is so annoying, i hate it. i turn it off but somehow it turns on again?

>it actually saves quite a bit of fuel

Maybe, if you live in a shithole city that mis-times its lights and queues up traffic just to piss of drivers.

This. Remember your turbo's oil feed is tied with the engine running. You cause turbo oil starvation, among other things. Stop/start is a meme that only works for emissions tests and for leasers who don't keep the car after the warranty expires.

Kill it with fire.

It's designed to otherwise the emissions testing organization can and will argue it's not a true "feature" of the car's efficiency and can discount it from emissions tests, meaning the manufacturer scores lower than the average and can be fined for it.

I rented a BMW with that shit.
It's annoying as fuck and I only see it causing problems down the line.
Fuck it and the person who designed it.

>he thinks a modern bmw's electrics and pumps just shut down the moment the engine is cut

I get it. You're stupid and associate everything in the world with what you know about your civic. But you need to accept that you're retarded and know fuck all about what you're talking about.

Half of the time people don't even know how to utilize it properly. I work in a drive thru, and I know when a car has auto start/stop because the drivers are so retarded they inch their car, come to a stop, the car autos off, then they push the gas to go another inch, and the car shuts off again. I wouldn't be surprised if these cars go through 8 or 9 on/off cycles just so they can get their small coffee

>I literally drive a modern BMW and have not seen proof that they don't
Post proof that what you are implying is indeed the case or I must take the default position that the pumps cut off, causing more wear. Why wouldn't I take the cautious position? I don't want my engine to break.

>stupid feature makes the car goes off when you stop
>you're supposed to turn it off when you're only stopping for 5s like in a drive-through
No man, it's a fucking stupid feature.

>what's a metropolitan area?

I'm not going to go dig through my owners manual for you but the battery doesn't fully shut down until after 30 or so minutes after the ignition has been cut. In my last 335 the manual stated that you didn't need to let the turbos cool after spirited driving; you could just shut the engine off because the battery would keep the oil going to the turbos regardless. It's not 90s subaru technology anymore. You can even fucking hear it after you shut the car down. Doubly so on my M3.

There's a reason there's a button to keep it permanently disabled right above the start button you fucking mong.

That's the water pump, not the oil pump. N55 engine in your 335 right?

>turbos
>s

N54

> if you live in a shithole city that mis-times its lights and queues up traffic just to piss of drivers.
So every city in the US.
Thanks for your input, fag

one more reason to not buy a new car and resurrect an old shitbox

Rented a 528i 2014, turned that shit right off

I found the car interesting how little storage space there is, and the backseat was surprisingly small for such a big car. It was comfy and I liked the adaptive suspension/ride in sport/comfort mode, but otherwise I wouldn't do it again, prefer a manual, or a golf R

>going from unreliable shit to even more unreliable shit

Why would you do this OP?

>the most interesting thing is the auto start stop feature.
The greatest wear to the engine occurs during starting the engine since the oil pump is not working and the oil has drained down. So let's put the engine through an abnormally high number of start cycles!!!

The cranking also causes large drain pulses on the AGM battery which has been shown to wear them out prematurely until a new more costly type of AGM (not commonly available) was developed.

Stop/Start type engines are for gaming the EPA mileage tests. Same for using 1.4L turbos pushing 150HP or more in a midsize car. The lifespan of running an engine hard all its life means it wears out sooner. But it will improve the gains on the EPA mileage tests.

>So every city in the US.
No, my city uses a combination of cameras and roadway sensors for those places without cameras. The cameras are mostly for downtown and major feeder road intersections next to downtown. The computer integrates all the information and changes traffic lights to keep traffic moving in the whole downtown area. It's much better than simply having roadway sensors to change the lights sooner (or not).

The n54 only circulates coolant when a hot car is turned off your oil is at a stand still in those journal bearings buddy

>oil is at a stand still in those journal bearings
So that means he should use full synthetic oil at the very least.

this shit is on par with the daytime high beams shit
>hurr retards cant see cars in broad daylight we better leave the lights on 24/7 we r making such a diference xdddd

>power steering suddenly dies at stops
I have a GM EcoTec car, and power steering remains available when the engine is stopped. I just tried it by turning the wheel back and forth and it is definitely available.

I don't think you can get more unreliable than a Jeep killing it's rear diff at 80k

>5th gear did a test and it actually saves quite a bit of fuel.
Frequent start/stop cycles sacrifices engine longevity to boost the mileage gains for EPA tests.

>the most interesting thing is the auto start stop feature.
It will just make you need to replace the engine sooner. That's a win-win for BMW because you'll probably buy a new BMW car instead of replacing the rough-sounding engine.

post evidence

It only disables start/stop for a short while. You use that when you are in a slow moving queue such as entering or leaving a parking lot after a football game, in freeway stop and go traffic, or lining up to go through a 4-way stop sign.

My car doesn't give me an on/off button. Instead, it tries to second guess me. If I have been inching forward and stopping a bunch of times for short distances, the stop/start feature is disabled until I start moving forward a large distance again. It might even decide to turn itself on such as when I had my foot on the brake pedal a long time, it stops the engine.

>if I did have it on how much fuel will I be saving?
The average car spends a large number of hours idling. So by putting in stop/start, the car manufacturer improves the EPA mileage rating by chopping out those fuel consuming parts of a test to emulate a car's usage.

Your viewpoint is therefore the number of starts and stops doesn't affect engine longevity.

When the engine is stopped, the 2nd car battery (in trunk) powers a lot of the auxiliary systems and infotainment system in the car. So I still have power steering and brakes and there is no lurch or shake when the engine comes back on.

>That's only if you stop
Many people do not come to a complete stop at a stop sign out here in the suburb areas. the do a "california stop".

One semi-infamous stop sign has almost 30% of the people ignore the stop sign as they simply drive right through it at almost full normal speed to get to their apartment complex. It's one of those foreigner resettlement apartment complexes that has subsidized housing for refugees.

>The starters are built for start/stop tho
Regardless of the depth of charge of the battery, each time the battery has to deliver such a large cranking amperage, the battery has to then redeposit the lead. Over time, the repeated removal and redepositing of lead becomes uneven, and the same problem that happens to liquid lead/acid cells also happens to AGM lead/acid cells.

god I fucking hate that nigger obama

Hybrids like the Prius and the Volt start and stop the engine constantly in traffic and city driving. They have no issues from it.

Pretty much this.
The engine always stops at top-dead centre, so it barely takes anything to get it going again.

An Audi with expired warranty would like a word with you.

>trump supporter cant into city
>waaaaaaa citys are shit
>he makes1/3 what city people make

Does it also run the AC compressor using electrical power or does the AC cause the engine to stay running?

>I don't think you can get more unreliable than a Jeep killing it's rear diff at 80k
Assuming dealers don't pretend they can't find the in-warranty problem, after the warranty expires, it becomes not just the failure rate. You have to consider the total cost of failure to establish an unreliability rate. To consumers, unreliable is basically the point where you have to give up, not that there is some niggling problem.

Exaggerated Example:
Jeep Failure, once per week, costs 1000 cents to repair, but no failure ever costs more than 1000 cents to fix. Fixes can be fixed with normal tools.

Audi Repair, once per year, has sets of failures that costs 1000 dollars total to repair, but no individual failure ever costs less than $500 to fix. It thus has better fitment than the Jeep. Approximately 15% chance a fix requires esoteric tool manufactured only in germany that costs no less than $200 each use.

For the above, the Jeep fails far more often and some people thus regard the Jeep as unreliable compared to the Audi. But for the practical person, the Audi is the failure despite running great and giving joy for a long time, it suddenly needs an expensive bigger repair.

>Does it also run the AC compressor using electrical power or does the AC cause the engine to stay running?

In my GM car with the engine stopped, the fan speed drops a lot but cool air still comes out due to residual thermal mass. The compressor is off of course since it on the serpentine belt. How long the engine stays stopped depends upon the modes picked when pressing the AC button.

The AC button has selectable modes of off, amber light, and green light. With Amber mode, that is full comfort so the engine will stop for awhile, but when the humidity or temperature rise up, it will turn the engine back on to power the AC compressor. With the green light, the ECO mode is selected. The compressor will remain off even if the humidity inside the cabin rises past a climate control point which is unknown to me.

I have not tried to test when it comes back on in this mode. But it will sooner or later. And off (no light) means the stop/start engine off time remains unaffected by the needs to maintain cabin temperature and humidity (climate control). Complicating matters is the selector for dual climate differences between driver and front passenger. The rear passengers are served by a total of 4 air openings. Both heating and cooling air are piped to them.

>the motor shuts off and turns back on automatically if you stop

this shit actually exists? holy fuck. it sounds like a disaster waiting to happen. how does it work? like when you stop for more than 10 seconds or something like that, the motor shuts off completely? then it turns back on when you give it gas?

i'm so confused. it sounds terrible for a motor to be shut on and off

i'm so fucking sick of auto headlights. i see so many fucking morons driving at night with just their headlights on because the fucking car has auto headlights and a dash that always lights up, so they don't realize they have their lights off.

if car manufactures are going to make all time headlights, then they might as well just make all fucking lights on all the time. just auto headlights are dangerous

This shit. I can't tell you how many times I've come up on someone unexpectedly in a curve becuase the jackass doesn't understand his lights are not fucking on.

I once drove one of those Bluemotion Golfs. As soon as you stop, you take your foot off the clutch and the engine stops, when you push the clutch back in the engine starts again and you can drive off. I think the design itself is pretty smart, probably rapes the battery though.

Yea I just turn it off. I've had 2 X1s that it and its gimmick factor ran out after a few days.

Reminds me of bumper cars. But instead of electricity, it's gasoline.

All euro cars have the stop/start feature coming?

Why does everyone get so autistic about this? When I drive my mum's 1 series with it I never notice it. As soon a you put the clutch in it starts back up again, literally a non issue

Auto Start/Stop is the biggest meme and is solely designed for EPA tests as others have said for 1-2MPG due to CAFE. In reality

>stop at a light in summer/winter: quantity of cool/hot air drops drastically
>starter much more likely to burn out, also rough on the engine
>delay of restarting in case of emergency

At least the Jeep and BMWs have buttons to disable it, some of the Chevy sedans don't and I get them as rentals + hate it.

>Why does everyone get so autistic about this?
Starter replacement is $2200 (dealer) on my car due to how its buried.

>the jackass doesn't understand his lights are not fucking on.
He manually sets his lights. You can turn off the automatic headlights and that is probably what he did. My car also lets me turn off the daytime running lights too. But if I forget to turn things back on, or go back to auto mode, the lights are off.

This thread is a great way to remind yourself that most of Veeky Forums has no fucking clue what they're talking about.

Well then it's a good thing that water cooled turbos only use oil for lubrication then, isn't it?

A lot of times, the person providing the criticism of two other people's answers is the one that is wrong. There have been cases where the two answers are both correct because the cars themselves were different makes from different years. Thus the implemented methods were different. The people providing the answers should have listed their make/model and year, but did not. Thus their answer became an unconditional absolute answer which of course contradicted other answers.

>if I did have it on how much fuel will I be saving?
No one knows how you drive. So no prediction on how much fuel is saved relative to your driving style.

modern stop/start cars have a tandem solenoid starter. The starter is fine and you hear 1000x more that "the starter is going to fail" than "the starter actually failed.

>less air
wtf are you even talking about? The engine is sucking in less air? Is that your point? Because if anything it sucks in like 1% more air while the car is moving with a ram air intake.

>starter likely to burn out
speculation that has since been disproven

What you are saying is that using the starter much more frequently has no effect on it being worn out.

No shit, I had a 328i on loan from the dealer for like two weeks and the auto start-stop was disabled the whole time. No idea wtf people are talking about with it coming back on on its own.

But user! You are saving almost $1 in gas you would have otherwise just burned away idling every year, EVERY YEAR user! Do you realize how much money that is saving you every time you stop your car? That alone makes up for the cost of starter replacement tenfold!

At least you can stop it. My car has no Stop function.

I drive a car with it, never have problems with it as it's a manual and you have to put it in neutral and release the clutch for it to work. I mostly use the system when I stalled the engine, as only using the clutch will start it back up.

On my bike I manually stop my engine at traffic lights, especially on hot days, passive cooling hates idling.

>how much fuel will I be saving?
none. start stop is a meme.

fibbi bibby

>if I did have it on how much fuel will I be saving?
It's really cost shifting. In exchange for having the starter frequently re-start the engine (thus causing more wear) and the starting current surge and subsequent recharge of the AGM battery, the mileage on the EPA test is increased significantly. The gain to the real-life driver is less than the EPA test though because drivers do not drive as "perfectly" as the EPA test due to the desire to accelerate or keep up with traffic. There's also the natural tendency to want to speed, so real-life drivers accelerate harder to get to their desired "normal" speed.

All that wastes gas and makes the EPA mileage next to impossible to achieve for most people. Thus, stop/start has less relevance to such drivers. When something has less relevance, that means its faults are magnified as those problems are no longer offset by the benefits.

So, unless gasoline becomes very expensive, like in Europe, the stop/start feature has less value in the USA. It's good at generating service business for dealers though if things like starters or solenoids can wear out. There are people who say that modern starters or solenoids don't wear out.