Stop/Start reduces oxidation and wear

[rneal55555_NH]

If you have fuel dilution that is going to cause engine failure before 200,000 to 250,000 miles Stop/Start isn't going to fix it.

I certainly don't know for sure but the dumb old submarine Torpedoman in me says you'll likely spend more on batteries and beefed up starters than you save in fuel unless nearly 100% of your driving is stop and go city driving. Go to a vehicle specific forum like the Bronco Sport forum where virtually all, if not all the vehicles covered have S/S and read the proliferation of failed battery/low voltage issue threads.

Stop/Start is just a way for the automakers to increase the gas mileage achieved on the Government mandated mileage test loop while spending minimum dollars per vehicle to achieve it.

Mine gets turned off. Wish I knew how to turn in off permanently.

 

[StumblingElk]

Lake Speed. Says it all . (Aren't he and Scotty Kilmer related?)

And is why I have over-ridden this "feature" on my latest VW and it stays in constant run mode from the start.

I don't know anything about lake speed but Kilmer has said many times that he isn't a fan of s/s features along with warnings of excess wear due to starting/stopping engines more than necessary

 

[StumblingElk]

Don't forget air conditioning!!

I mean....I've heard counter claims from other engineers and tribologists. Not only that, but opinions/results will vary because of the variation of oils, engines, fuels, and fuel systems.

As far as MPG savings.....it's minimal and again, dependant on the platform/situation. I've seen various testing that shows anywhere between 1% and 8%. We then have to factor in any excess wear (again, dependant on platform and other variables). Properly inflated tires and driving conservatively would likely yield better fuel savings for many people

 

[dnewton3]

IOW because we don't know the Stdev values for the test methods used to arrive at the various values there's no conclusion to draw.

Not the "test methods"; rather, I'm talking about the data itself. (The gauge R&R conversation is separate; let's not conflate that topic with the data topic.)

To be completely accurate in answering your question; Yes - you can draw a conclusion from the one UOA ... A really bad, flawed, misleading conclusion. Which is what LSJ has done here.

There is no accurate and credible conclusion to draw when only one (or a few) samples are used in situations like this. It takes a MINIMUM of 30 sample sets to establish a reliable Stdev; that is the low end of acceptable. This isn't my opinion; it's the mantra of every single statistical process control program (such as "Six Sigma", etc) known to the developed world. Not a single sample, or a few, or 10, or 20; you need a MINIMUM of 30 samples. As the quantity of samples taken diminishes, so does the accuracy of the Stdev calculation; so much so that the error factor in small sets of data can induce wildly incorrect information.

Do you think LSJ knows enough about his own product to make that determination? Do you trust that he does?

Are you referring to his UOA services as a "product"? If so, then It's readily apparent to me that he does not know the limits of the tools he's using. Further, I don't trust that he does; it's obvious he's clueless about said concerns or he would never participate in such misleading statements and implied conclusions. To be fair, he's not alone ... probably 98% of the BITOGers also don't understand what a UOA can and cannot tell us about oil and wear.



Ever read this?

Used Oil Analysis: How to decide what is normal - Bob is the Oil Guy

Reviewing UOA Data Used oil analyses (UOAs) are tools. And like most tools, they can either be properly used or misused, depending upon the application, the user, the surrounding conditions, etc.= There are already many good articles and publications in existence that tell us how to interpret...

bobistheoilguy.com

 

[BMWTurboDzl]

Are you referring to his UOA services as a "product"? If so, then It's readily apparent to me that he does not know the limits of the tools he's using. Further, I don't trust that he does; it's obvious he's clueless about said concerns or he would never participate in such misleading statements and implied conclusions. To be fair, he's not alone ... probably 98% of the BITOGers also don't understand what a UOA can and cannot tell us about oil and wear.



Ever read this?

Used Oil Analysis: How to decide what is normal - Bob is the Oil Guy

Reviewing UOA Data Used oil analyses (UOAs) are tools. And like most tools, they can either be properly used or misused, depending upon the application, the user, the surrounding conditions, etc.= There are already many good articles and publications in existence that tell us how to interpret...

bobistheoilguy.com

Yes I'm referring to the limitations of the test methods used to generate the date for the UOA. I also don't think LSJ is basing his opinion off this single vehicle. I've read the link a few times

In any case with this particular vehicle I guess we're left with the fact that it's not going to be possible for the owner to determine the impact of s/s on engine wear because it's just 1 power unit and the operating conditions are varied.

In fact we, at BITOG, can't make a determination when it comes to choosing between employing S/S or dealing with fuel dilution because there is no data set available.

 

[Jetronic]

I wonder if you permanently disable start stop on a new vehicle if the starter will most likely last the life of the vehicle?

It did on mine... but the life was cut short by an accident at 130k-ish miles

 

[chris719]

Lake is an intelligent guy, but I'm pretty sure this is just shilling for his UOA service. This isn't a very scientific test, and I also do not believe that UOA can tell you much about wear. There have been examples of BMW S65 and S85 engines throwing rods from spun rod bearings and the UOA history was actually quite good and did not show elevated metals. The simple ICP analysis has severe limitations. It might show you wear in some cases, but there is no guarantee you are getting an accurate picture.

 

[chris719]

Why bearings failure rates are tripled then?
Here's an article that was written on Amsoil:

How Start-Stop Engines Challenge Motor Oil - AMSOIL Blog

Start-stop cycles in equipped engines can triple compared to traditional engines, increasing the likelihood of bearing wear.

blog.amsoil.com

The bearing wear is an issue. This is why everyone is moving or has moved to coated bearings. It's also why I don't enable auto S/S on my car.

 

[Thermo1223]

The bearing wear is an issue. This is why everyone is moving or has moved to coated bearings. It's also why I don't enable auto S/S on my car.

Well bearing wear is always an issue. The industry is forcing oil manufacturers to respond with better oil and in turn forcing bearing manufacturers to do the same with coated bearings. It really hard to quantify what effect S/S has on the life of an engine when there are several other factors at play. One UOA certainly isn't going to tell you anything and even a lifetime of them may tell you very little. I am not advocating for it all mind you, it is annoying.

 

[Nesterenko]

I'm aware of his qualifications and his history within the industry (ex, lubricant development for race teams). Just curious as to yours.

In any case you must re-read what I said. In his professional opinion the wear caused by fuel dilution is greater than the wear caused by S/S systems. So if you have a known fuel diluter with s/s, then use the s/s system.

So wouldn't using S/S on a fuel diluter actually exacerbate the condition?

 

[BMWTurboDzl]

So wouldn't using S/S on a fuel diluter actually exacerbate the condition?

He suggested that the excess fuel comes from idling.

 

[Nesterenko]

He suggested that the excess fuel comes from idling.

Wouldn't the oil not stay as hot when the engine is stopped. Isn't hotter oil to a certain point of course, beneficial to mitigate fuel dilution. It may be nitpicking but...

 

[BMWTurboDzl]

Wouldn't the oil not stay as hot when the engine is stopped. Isn't hotter oil to a certain point of course, beneficial to mitigate fuel dilution. It may be nitpicking but...

My guess would be low tension rings and direct injection which allow excessive blowby at idle.

 

[FaronJ]

Thank God my 2015 Impala 2LZ doesn't have that irritating S/S!
( Wouldn't have bought it if so equipped!!! )
Right or wrong.......I could care LESS about gas-mileage. I'll let other people save the world the half-gal of gas/year/car.

Faron

 

[demarpaint]

I'd still leave it turned off even if there was truth to the "test."