Ye think Idle stop engines == bad for oil?

[theaveng]

Originally Posted By: demarpaint
Now we have another problem coming soon to be looking for a cure: stop start technology. Someone please tell me how that can possibly be good for an engine? ...Is the fuel savings going to outweigh the cost of starters, batteries and additional engine wear? I guess the powers that are pushing for higher fuel economy don't care about that.
I understand the concern, because I had the same concern ten years ago, but don't see any real issue. My Honda turns itself off below 20mph, and then restarts when I shift to 1st gear. It's really not a big deal. There's no more extra wear rotating the engine from 1000 to 0 and back to 1000 rpm (versus going 1000 to 2000 and back to 1000).

And the electric motor doesn't care either. Whether it's assisting the engine to move from 0 to 1000 rpm, or 1000 to 2000 rpm, or 2000 to 3000 rpm, it's just doing what it was designed to do: Spin.

 

[demarpaint]

We must have posted at the same time in different threads. The start stop technology I was referring to is for non hybrid vehicles. I wasn't clear on that. It does cause additional wear to the starter, as well as the engine, each time the engine has to be restarted.

 

[friendly_jacek]

Originally Posted By: demarpaint
It does cause additional wear to the starter, as well as the engine, each time the engine has to be restarted.


If you use conventional starters, then yes on starter wear, but are you sure starters are used?

As for the engine wear, you can minimize it by delaying ignition and fuel before oil pressure develops. This is what hybrids do.

 

[NHGUY]

Arent they using a belt drive starter/generator to crank the engine?

 

[demarpaint]

I was reading up on it, and the complaints that some BMW owners have with the system. At least it has a button to deactivate the system, but by default it is reactivated each time you start the engine again. The dealers were issues a Service Bulletin to accommodate customers unhappy with the system. "BMW has given dealers permission to activate the system's Last User Mode, which will start the car with stop/start in the same mode as when the car was shut down. Of note, BMW M models come with Last User Mode enabled automatically." It seems there are enough people unhappy with it for them to issue a bulletin about it.

I have no idea what starter BMW uses with their system, or what Chrysler is using in with theirs, I'll be reading up on it, it does interest me. I'm sure doing what you mentioned can minimize wear, I'd rather pay the extra $ for gas and let the engine run at lights rather than have it on and off. Now hybrids, that's another story. This is just my opinion.

 

[getnpsi]

My old aspire ford had over 165,000 miles on it and then I used it just for delivering pizzas probably starting the car at least 30 * a day and that starter went along in an engine swap is still running. Warm starting a car is very easy on oil and engine is well

 

[SwampSurvivor]

I used to do a lot of around city driving in my Focus. I'm not as worried as it usually was kept up to temperature all day.

However, I do question how long the stock starters will hold up. Especially if you spend all day in stop and go traffic.

I haven't seen the topics that this was created from, but doesn't Nissan use a system to bump the engine backwards (via spark) and then start it thatway?

 

[JHZR2]

Would I be concerned at initial start and the first few stop signs and lights on a commute at -10F.

In the summer or any normal condition, lets just call above freezing? Wouldn't bother me at all. In fact I manually do this in some conditions.

And for a warm engine with battery at full state of charge, I see the extra cycles as nearly irrelevant.

UPS shuts off their truck at every house they stop at. I'd imagine that if it was poor economics, they wouldn't.

If there is some implication of fuel dilution due to some startup enrichment, I doubt the duration is long enough to make a difference.

The only concern I'd imagine is enough heat loss to take the o2 sensors offline or cool the catalyst enough that it has to light off over and over.

 

[demarpaint]

Originally Posted By: JHZR2
Would I be concerned at initial start and the first few stop signs and lights on a commute at -10F.

In the summer or any normal condition, lets just call above freezing? Wouldn't bother me at all. In fact I manually do this in some conditions.

And for a warm engine with battery at full state of charge, I see the extra cycles as nearly irrelevant.

UPS shuts off their truck at every house they stop at. I'd imagine that if it was poor economics, they wouldn't.

If there is some implication of fuel dilution due to some startup enrichment, I doubt the duration is long enough to make a difference.

The only concern I'd imagine is enough heat loss to take the o2 sensors offline or cool the catalyst enough that it has to light off over and over.


The -10 situation you mentioned would be tough, or heavy NYC type traffic, where you move 10' stop for a few minutes, move another 10' and repeat for an hour or more. Testing it under conditions like many NYC commuters do year after year would make an interesting test. Then compare fuel savings for the life of the vehicle vs. additional repairs if any and see if its worth it or not.

As far as UPS I'm sure they calculated their savings, and reduced their liability by no longer leaving vehicles running while unattended. At least that's what I was told by a UPS employee I know. They're actually pretty strict about turning a truck off while making a delivery, you can actually lose your job for not doing so.

 

[onemig]

Don't they restart the engine by injecting fuel and ignition to the piston that's TDC?

At least from what I know this is how Mazda's Skyactiv works.

 

[mechtech2]

Heaters, defrosters, and air conditioners don't like it.

 

[Shannow]

Originally Posted By: theaveng
There's no more extra wear rotating the engine from 1000 to 0 and back to 1000 rpm (versus going 1000 to 2000 and back to 1000).


How do you figure that ?

When at zero RPM, there is zero hydrodynamic lubrication, a phenomenon that only exists when there is differential movement between two surfaces.

Want an example,look at the ring ridge effect at the point of zero piston velocity.

It's there, it's demonstrable, and id simple laws of physics stuff, which while poopooed on this board (laws of physics), are actually out there.

Now if you state that a Honda so equipped will likely provide you years of trouble free service, as the engineers have proven that the reduction in life is 5, 10, 15%, on a life which is still typically longer than most cars survive, I will agree with you.

The zero extra wear is just wrong.

 

[mkosem]

Originally Posted By: JHZR2
Would I be concerned at initial start and the first few stop signs and lights on a commute at -10F.

In the summer or any normal condition, lets just call above freezing? Wouldn't bother me at all. In fact I manually do this in some conditions.

And for a warm engine with battery at full state of charge, I see the extra cycles as nearly irrelevant.

UPS shuts off their truck at every house they stop at. I'd imagine that if it was poor economics, they wouldn't.

If there is some implication of fuel dilution due to some startup enrichment, I doubt the duration is long enough to make a difference.

The only concern I'd imagine is enough heat loss to take the o2 sensors offline or cool the catalyst enough that it has to light off over and over.


Don't engines with stop/start not enter stop/start mode until they reach operating temperature?

--Matt

 

[Mr_Incredible]

Wouldn't you think that the engineers that built the technology would have built the starter system to survive the increased cycles? I don't imagine they used the same old starter that they place on normal cars.

And as said earlier, starting a warm car with a charged battery isn't very tough.

How your oil fares would depend on what duty cycles your driving would incur. Longer drives on a warmed up car keep the oil hotter. Shorter drives in the city, with EV cycles prevalent would keep the oil cooler. I see this on my scangauge with the coolant temp and would think the oil follows the same curves.

My Prius C has a screen that tells you how much of your last drive/tank/total was in EV mode. Generally, for me, it's about 20-30 percent in the summer. Less in the winter with the heater going all the time. We'll see what the spring oil change and analysis shows, and I have one out right now that should be here in a day or three. It has some colder days on it. I don't see a problem with the technology, but I can see that those with no knowledge of it might give it stink-eye.

 

[KrisZ]

I have no firsthand experience with start stop technology, but I read about it. Most of the stuff I read mentions that the mode will not activate until certain coolant temperature is reached. Also, cars utilizing regular starters are equipped with heavy duty starters.

Another thing that is neat in hybrids is that the electric motor will spin up the engine to certain RPM before the ignition is activated.
There is a Civic Hybrid on my street and a couple of times I was walking by with my dog when the car was started. It was pretty neat to hear that electric motor hum and spin up before hearing the engine fire up.

All in all, I think manufacturers didn't just slap on start/stop gizmo before ensuring that it doesn't affect the engine longevity.

 

[TFB1]

Originally Posted By: demarpaint

As far as UPS I'm sure they calculated their savings, and reduced their liability by no longer leaving vehicles running while unattended. At least that's what I was told by a UPS employee I know. They're actually pretty strict about turning a truck off while making a delivery, you can actually lose your job for not doing so.


Leaving a running vehicle unattended is illegal in most states... That would trump any other reason...

 

[demarpaint]

Originally Posted By: TFB1



Leaving a running vehicle unattended is illegal in most states... That would trump any other reason...


There you have it.

 

[theaveng]

Originally Posted By: Shannow
Originally Posted By: theaveng
There's no more extra wear rotating the engine from 1000 to 0 and back to 1000 rpm (versus going 1000 to 2000 and back to 1000).
How do you figure that? When at zero RPM, there is zero hydrodynamic lubrication, a phenomenon that only exists when there is differential movement between two surfaces. Want an example,look at the ring ridge effect at the point of zero piston velocity.
Ring ridge?
That's a good point but the surfaces still have oil in between them. 30 seconds of idlestop isn't enough for the oil to drop out.

I'm doing an oil analysis at 7000 so I guess we'll find out. I use idlestop frequently (but not when cold; it is disabled until the engine gets warm).

Idlestop is also disabled if the A/C is engaged, unless you press a button to reenable idlestop.

 

[lexus114]

Originally Posted By: NHGUY
Arent they using a belt drive starter/generator to crank the engine?



Yeah like the old I/H Cub Cadet`s!! Hahaha

 

[theaveng]

Originally Posted By: theaveng
I'm doing an oil analysis at 7000 so I guess we'll find out. I use idlestop frequently
But I redline frequently too, so that might skew the results. Maybe I should start limiting myself to 4000rpm max (like a prius does).