Increased oil/filter capacity for sludge-prone engine w/short trips???

[Audi Junkie]

It seems, in certain circles, there is a rush to increase oil capacity with extra big filters on some sludge-prone engines. Lowered OT is a way to prevent oxydization and coking in hard-driven and tracked cars, but what about short-trippers? How can reducing OT benefit cars that drive 1-5 miles on diaper runs? Would extra capacity and extra time to reach self-cleaning temps (if at all) be a clear benefit? Is the "bigger is better" mentality just a run-away supposition?

 

[Steve S]

An opinion only on this matter,I would guess that the problem is caused when the engine is turned off and the oil cooks on the hot areas due to poor design. If so I don't know if more oil capacity will help.

 

[Gary Allan]

I don't think that oil capacity alone will reduce oil temp. It will delay it reaching its peak or normal temp (for prevailing conditions) and may dampen some changes ..but it shouldn't really alter it. but I agree with your basic premise that more may not be better in the conditions that you describe. The only counter or co-thought being is that since you may never get to operating oil temp (high enough) that any fuel dilution and whatnot will be distributed over a larger sump.

 

[Big O Dave]

I'm still grieving that I can't fit the GIGANTO 51714 on my F250 or my wife's Explorer. To me, it's not the increased oil capacity that is so desireable about big filters, it is the ability to hold the same amount of crud while flowing more... this is what I like. But, having said that, I wonder now how much longer it takes for my oil to warm up when using a filter that holds a half quart more oil... One thing I've noticed about my oil pressure is that ever since I entered my first rinse stage with ARX and have been using a mix of Castrol GTX 20W-50 and Proline 10W-30 (compared to Rotella "Synthetic" 5W-40 while in the first cleaning stage of ARX), it reaches normal operating pressure much more quickly than it did with the Rotella. To me, this indicates that this rinse oil mixture reaches normal operating temperature faster, which causes it to reach normal operating pressure faster. What I'm getting at is that in this experience I'm seeing that certain oils get to operating temperature more quickly than others, and perhaps this may be of a more dominant influence than the extra oil capacity. It seems there is something new to observe each day, now that I'm seeing through more tribologically-oriented eyes.

 

[haley10]

AJ, I think if we look at each specific case of sludge like the cat being too close to components, oil galleries being routed near fire zones, etc. I think the extra oil from an oversize filter would help little if any, especially if oil is pooling in the heads. I would focus more on best oil available and shorten oci. I'm skeptical of grossly oversizing filters as that can get you into other problems potentially and not solve anything.

 

[John_E]

For an engine with a grossly undersized sump, such as a longitudinal VW/Audi 1.8T, a larger filter makes alot of sense and is now mandated for warranty coverage. My only real answer for short trips and/or stop-and-go driving is the same as everyone else's: an OCI of 4 to 6 months or 3K mi/5K km, whichever comes first.

 

[Audi Junkie]

My question is: how can LOWERING OT and increasing time to self-cleaning temp help an engine that experiences short 1-5 miles trips?

 

[theguru]

I would suggest that in the very short run scenario givem it would be counter-productive to increase filter size. My suggestion is to change oil more often or if you are concerned about filter capacity, change the filter mid way through the OC cycle and top off.

 

[Gary Allan]

quote:

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My question is: how can LOWERING OT and increasing time to self-cleaning temp help an engine that experiences short 1-5 miles trips?

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It can't ..except to the limits that any insult experienced by the oil will be distributed over more oil ( as I think I stated). That is, let's say you alter the sump by 10%. It may alter your temp rise time by 10% (I really don't think it's that direct a relationship) ..but it's a moot point since you never get to anywhere near any "self cleaning" oil temp anyway (which is kinda what you imply with your conditions). So, what do you have to lose except reduced dilution due to the added, albeit slight, increase in sump capacity?

 

[Audi Junkie]

I see your point Gary. I am outfitting a friend's 1.8t with the normal sized filter since she does all short trips.

 

[Gary Allan]

Does this engine have a heat exchanger on it? If so, then she would be best served with a smaller sump, where the coolant would be more able to bring the oil temp up sooner. I see your goal here. You appear to be doing the proper "corrective" action in the only way that I can see to combat the effects of this type of service. I think at this point it's down to the length of the OCI. If she doesn't have an oil/coolant exchanger, you may be well served to research the possible installation of one. The VW/Audi sandwich cooler is relatively cheap used (and new if you don't mind a Chinese knockoff) on ebay. Good luck