stop/start oil filtering question

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I was in Cali recently and while walking around noticed that a LOT of the start stop equipped engines were euro luxury cars. I'd just be walking down the street and then you hear that distinctive quick turnover sound and off they went. The 're-start' is definitely quicker than a typical crank over first thing in the morning.

Will be curious how those same cars fare after 100k miles and on the 2nd or 3rd owners.
 
Originally Posted by PimTac
The modern start stop systems are not totally reliant on the starter to restart the engine. There is also some pre-oiling happening just prior to the restart.



How is that happening? Most of the engines are just existing designs with the electronics of s/s added to them. I don't know of any engine that has a pre-pressure device on it. These engines typically are just using the "normal" oil pump.

Remember the age-old addage that "75% of engine wear happens at start up"? Frankly, I never bought into that. But it was prevalent for a long time. To many topics therein to just believe such a blanket statement. Measured how? Oil at what temp? Engine at what temp? Duration of use between starts? Duration of cool-down between starts? Etc ...

It would be interesting to see if we can get enough data for a good study in terms of wear control with this s/s technology. Pick some engines that have s/s, and have some folks use the feature, where others defeat/delete the feature. Run a lot of UOAs and get the macro data.
 
Originally Posted by dnewton3

It would be interesting to see if we can get enough data for a good study in terms of wear control with this s/s technology. Pick some engines that have s/s, and have some folks use the feature, where others defeat/delete the feature. Run a lot of UOAs and get the macro data.

That would be very interesting, I for one would love to see it. It would take years to accomplish. Maybe you could make a sticky to start recruiting stop/start owner participants to get the ball rolling?
 
Only thing that's really taking place with start stop systems is the life of the starter is being cut in half
Every manufacture that's doing this crazy crap now is gonna sell a boat load of starters in a few years
 
As far as the filter goes that may not be as an issue as other things. per Wiki...
Concerns
The US National Highway Traffic Safety Administration (NHTSA) raised questions about non-hybrid Honda vehicles equipped with the company's 'Idle Stop' transmissions in February 2001 due to concerns over the "sudden lurching forward of a vehicle in an automatic restart" - rather than the "gradual creeping forward found in current transmission designs." [40][41]

Hybrid/electric assist vehicles experience almost no delay in power from a stop, due to the instant availability of power from the traction battery to the electric motor(s). Gasoline/microhybrids on the other hand generally experience slight delays (albeit fractions of a second).

Many people[who?] think that long-term use may induce additional wear due to lack of oil lubrication. For the crankshaft bearing half shells and the big end bearings this can translate into frequent high-speed rotary movement before a hydrodynamic film is established. During this phase of boundary lubrication, metal-to-metal contact can occur between the crankshaft surface and the bearing's sliding surface. This was not an issue while the number of engine restarts totaled at what was generally understood to be a normal magnitude. However, in a vehicle with start-stop system this effect can necessitate new technological solutions to avoid premature bearing wear, depending on the driving cycle. Consequently, future engines for start-stop applications need to be designed for 250,000 to 300,000 starts. Traditional bearing shells with aluminum or copper lining show severe wear after only 100,000 cycles. In a start stop system the short stop times keep the engine and oil warm, retaining lubrication.[42] Some implementations do not use a starter motor[citation needed], eliminating concerns of starter motor wear. Mazda i-stop used in their Mazda3/Axela line (in Europe and JDM) uses combustion to assist the starter motor by sensing the position of the piston in the cylinder. They claim quieter and quicker engine restart within 0.35 seconds.[43]

Start-stop systems are heavily reliant on the battery. Testing indicates that AGM batteries diminish in their ability to support start-stop functionality over time. [1]. While alternatives exist (NiZn, Lithium-Ion, supercapacitors,[44] PbC), virtually all automakers continue to use conventional AGM lead acid batteries.

Some car makers such as Suzuki have one lithium-ion battery inside the car.[35]
 
Originally Posted by dnewton3

How is that happening? Most of the engines are just existing designs with the electronics of s/s added to them. I don't know of any engine that has a pre-pressure device on it. These engines typically are just using the "normal" oil pump.

AFAIK, start-stop uses PMGR starters, AGM or EFB batteries and a few control algorithms to operate. No pre-oiling is provided. There is a transmission difference in some systems. ZF does have a Hydraulic Impulse Module to allow the transmission to engage into D immediately. It's more or less an accumulator in the transmission's hydraulic circuit.
 
Originally Posted by dnewton3
Remember the age-old addage that "75% of engine wear happens at start up"? Frankly, I never bought into that. But it was prevalent for a long time. To many topics therein to just believe such a blanket statement. Measured how? Oil at what temp? Engine at what temp? Duration of use between starts? Duration of cool-down between starts? Etc ...

If the engine is warm and there's a good layer of oil I doubt it makes a difference. It would be cold starts that would be the most stressful. If the engine/oil is hot then it should come up to pressure almost immediately, plus the residual oil film. I can look at the oil through a filler cap, and even an hour after the engine has been shut off I can see the oil coating every single part of the engine that would be exposed to oil.

I was thinking maybe it could stress the antiwear additives, but not necessarily if there's a good film of oil stuck to the engine parts.
 
I thought I say a report (by the SwRI comparing engine wear between 0W-16 to 5W-30 oil) on a DI engine posted a while back that included stop/start operation. I'll try to find the link and post it up, or someone else might be able to find it and post it.

Edit - do a Google search for CRC Report No. AVFL-28.

I'm on my phone and can't get the direct link.

The test data shows a relatively high level of wear during stop/start use conditions, especially with the thinner oil.

Note that the report said there was no measurable wear in the journal bearings, which I found surprising.
 
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