The standard answer is 5W-30 motor oil that meets API SM or newer specifications, with a typical fill of about five to six quarts including a filter.
The 2007 Outlander was offered with two gasoline engines—the 2.4-liter four-cylinder and the 3.0-liter V6—so exact capacity and any climate-specific tweaks can vary. Check the owner's manual or consult a Mitsubishi dealer for your specific vehicle.
Oil specifications and engine options
2.4-liter four-cylinder
The 2.4 L engine generally calls for 5W-30 oil meeting API SM or newer. Capacity is typically in the five-to-six-quart range with a filter, depending on drain and replacement practice.
3.0-liter V6
The 3.0 L engine also uses 5W-30 oil that meets API SM or newer. Capacity tends to be around six quarts with a filter, with exact amounts varying by service method.
Maintenance notes
Use a reputable brand and choose conventional, synthetic-blend, or full synthetic oil as long as it meets API SM or newer. If you live in extreme temperatures or do a lot of short trips, follow Mitsubishi's recommended change intervals and check the level regularly with the dipstick.
Summary
For a 2007 Mitsubishi Outlander, the typical oil specification is 5W-30 oil meeting API SM or newer, with an approximate oil capacity in the five-to-six quart range including the filter. Since there were two gas engines that year, always confirm the exact specification for your vehicle in the owner's manual or with a Mitsubishi service representative.