How much oil do I really need?

My 8.3 /350 horse will reach the full mark with 24 qts I put 22 and run it, then dip it again it always takes 2 more.

Yes I fill the filter and count them in the 22.

The important issue here is the accuracy of the dip stick. The dip sticks were fit by the chassis maker, not engine maker.

What I would do:

Call Cummins with your engine serial number and CONFIRM CORRECT CAPACITY WITH FILTER: Cummins 800 343-7357

At the next oil change, calibrate the dip stick. Cost is $0. Here is the procedure:

At the next oil change, drain oil, remove old filter (as usual). Then install the drain plug and new oil filter and add the engine's correct oil capacity LESS THE NUMBER OF QUARTS you want between the "ADD" and "FULL" marks (let's say 2 quarts). So for an engine with 20 quart capacity you would add 18 quarts. Run the engine a few minutes, shut off and wait until oil has descended into the pan (at least 30 minutes and an hour is safer). Pull the dip stick and use a file or dremel tool to mark the oil level "ADD". Add the remaining two quarts, let the oil settle in the pan, pull the dipstick and mark this the "FULL" mark.

Also, when checking the oil level with the dipstick it is safest to do it in the morning after the oil has had all night to flow back to the pan.

Do not add oil until the level reaches the ADD mark.

Finally, make a sticker to affix near oil fill: OIL CAPACITY INCLUDING FILTER: xx QUARTS.

Have the shop calibrate your dip stick. I taked to CAT and they advised me to do that. Now it reads right

Please do not do a dry start. Add oil to your filters, you can cause some serious damage to your engine filling those filters ON the engine. The theory as stated above might sound good, but make the call to the Cummins people as stated with the numbers mentioned.

just me wrote:
Please do not do a dry start. Add oil to your filters, you can cause some serious damage to your engine filling those filters ON the engine. The theory as stated above might sound good, but make the call to the Cummins people as stated with the numbers mentioned.

Two different schools of thought on that. I know that Caterpillar Corp recommends AGAINST filling the filter, as the couple of seconds it takes to fill the filter is less a risk to the engine than the potential of introducing particles post-filter media.

How about a compromise: Fill the filter, but only THROUGH THE SMALL OUTER HOLES (INLETS), NOT CENTER LARGE HOLE (OUTLET). Takes more time, but satisfies BOTH schools of thought.

I agree with Wolfe. I always fill my oil filter prior to putting it on the engine, but I fill ONLY through the smaller outer holes.

Ed Headington

pouring fresh oil from a newly opened container should not contaminate the oil system in any engine.

I simply fill the whole flitter can with clean oil. brain dead simple.

Tom/Barb wrote:
pouring fresh oil from a newly opened container should not contaminate the oil system in any engine.

I simply fill the whole filter can with clean oil. brain dead simple.

Actually, a retired petroleum engineer, also a member of the Diesel RV Club, said at one of our seminars: "Do NOT trust that new oil out of a can has zero contaminants."

Filling the oil filter outlets fills both concepts. Same for fuel filters.