? on diff in sump size and gas vs diesel

[Gator]

? is lets say we run Dello 400 in a Diesel pickup 12 quart sump capacity for 7,500 miles or 6 months unloaded and used for basic delivery of small parts, now if we was to use this same oil in a older 1996 to 2000 chevy or ford 1/2 ton v-8 gas truck with a 5 quart sump capacity used for the exact same job what would the OCI be ?, about the same as the diesel or longer. I no the gas engine has less oil capacity but it would not be subjected to the heat of the diesels turbo and with the gas truck the engine would come up to normal operating temp quicker. Whats your general opinion on the OCI for the 2 engines.

 

[Mokanic]

Surely Delo would be capable to run longer in a 12qt sump truck that is in good working order. If not,I would switch to something that could. Now 5qt sump truck engines should be set by analysis.

 

[Johnny]

Actually, both should be set by analysis, don't you think? As for as operating temps, what makes you think the gas engine gets there faster?

 

[Jim 5]

Originally Posted By: Johnny
As for as operating temps, what makes you think the gas engine gets there faster?


This is my experience moving from a Chev 5.3L v8 to a GMC Duramax. It takes forever to get the diesel up to temp. Diesels are way more thermally efficient. For short trips, in a northern climate, you may never spend any time at full operating temp in a diesel, which is why I installed a winter front, an oil pan heater and run that and the 1200w block heater 3 hours before I leave for work.

Even still, the gasser would get to full operating temp (not plugged in) at -20C faster than the diesel which had 3 hours of block heater and oil pan heater.

 

[Mokanic]

Yes, you are correct as far as setting the analysis of gas and oil hammer engines.

 

[Gator]

OK analysis is the sure way to find out, but not the opinion i was looking for, since i could change the oil on the gas truck for the cost of a analysis, i would simply change the oil. I was just getting a idea on the difference you think in gas and diesel engines.

 

[Steve S]

The Delo should be able to outlast passenger car motor oil easily. The uoa would prove to you that the oil is holding up for lets say 7,500. Then if the uoa looks good you can say the interval is good and as long as the engine runs good you don't have to always do uoas.

 

[Gator]

So guys throw out the analysis,,, and go only on your gut feeling. Which is harder on oil 12 qt diesel engine with turbo, or a 5 qt v-8 gas truck. If they were both 12 qts the gas truck would be able to go very long OCI but with a 5qt I would be "skeered"to go much over 7,500 OCI. But there is guys on here going 10,000 with M-1 EP, I would like to think a dino HDEO could do the same.

 

[dnewton3]

You want opinions and guesses; that's what you are getting.
You want facts? Get a UOA. I realize they are not cost effective for small sumps, but if you want the info, you have to pay for it.

Not sure we can give you a "certain" figure that will suffice; it's an estimation. Part of the decision is based upon your unique sitation. I don't know of any light-duty diesel engine that takes exactly 12 quarts. PSD and ISB engines take more; Dmaxes less. (I've never had an ISB, so I cannot comment directly on the sump size). The sump capacity is only one contributor in the OCI decision. Sump size is not a direct indication of the OCI duration for any given lube, at least in a linear sense. Dmax engines are notoriously easy on oil; 10k miles on dino oil is not unheard of, as confirmed by UOAs and OLM. PSD's are generally hard on oil viscosity; many change oil at 5k miles to be pre-emptive, rather than spend $ on a UOA.

An OCI certainly negates the cost of the UOA on a small sump gasser. As the sump grows, the cost of the UOA (service brand dependent) can get much closer. CAT UOAs are fairly resonable in cost, and a OCI in a PSD can be fairly costly. All things must be considered. Further, if one were to make the investment of a few UOAs in succession, then one could decide to extend the OCIs based upon information gleaned from the UOA, thereby spreading the cost of the UOAs over many multiple OCIs, greatly reducing the cost per OCI (your basic concept of amoritization).

Also, you mention an "older 1996 to 2000 chevy or ford 1/2 ton v-8 gas truck with a 5 quart sump capacity" which isn't correct either, because IIRC the trucks of that vintage take 6 quarts with filter. Not that it matters much, but is it a Chevy or a Ford? I personally think both are likely to survive well, as the engines of that decade were well constructed.

If you want to compare a PAO gasser lube to a dino HDEO, I'd say (as a SWAG) the OCIs would be reasonably equitable. But I qualify that statement with a HUGE caveot of "it depends ..."

Seems like you want a specific answer to a generic question. You throw out hypothetical situtations and want determinate results. Don't think you can get there from here ...