Thanks for referencing that site. I downloaded the Owner Manual from there for a 2004 (non available there for my 2003 to download) a year or so back and have used it a lot to look up info both for myself and for responding to Posts on this Forum. It's in .pdf format and is very searchable, therefore easier to use than my hard copy.
From the 2004 Owner Manual, for the 4.0L
, 10W-30 is the preferred oil to be used above 0F. 5W-30 can be used from 32F downward. Being a 10W-30 fan, I use mostly 10W-30, may go to 5W-30 for January & February. Interesting enough, the 4.0L V6, used in the newer Dodge Grand Caravans, calls for 10W-30 for all seasons, no options given other than 10W-30 synthetic. There must be something about "flowability" additives in the conventional oils that we don't know about.
As for filters, I go for oversize filters such as Fram Tough Guard TG-8A or the Mopar filter specified for Fords to use in place of the Ford FL-1A. Mopar filters in Canada are white, made by WIX (black and by Purolator in the US). The Canadian Mopar # for the oversize filter is 0FE00148. If I weren't getting the Mopars for $2.75 "trade price" (lists at $4.95), I would go for the Fram Tough Guard at $8.00. The Fram is a superior filter with a silicone (versus nitrile) anti drainback valve and a high efficiency filter media (over 99% efficient).
Another thing I like about Fram is that they tell you about their filters, including efficiency per ISO standard tests, whereas most others keep you guessing. Been a little interested in oil filters and have cut Mopars, WIXs, Ford FL-1As and Fram TGs apart to examine their inards.
As to oil, I just bought 4 - 5L jugs of Quaker State 10W-30 to add to my stash which includes a jug of Valvoline 10W-30 and a jug of Pennzoil 10W-30. The Quaker State was on sale at WalMart for $10.88, pretty hard to beat that price. It had the API label on it including the Starburst symbol. If you are looking at "High Mileage" oil, you may not see the starburst symbol.
Quantity is per your Owner Manual, 5 quarts or 6 quarts, 6 being for the six cylinder engine, 5 for the four cylinder engine. I add a little more when using the oversize filter.