I would only consider ignition upgrades if you are running some sort of high compression or e85 setup with advanced timing and wide spark gap, along with icam and exhaust mods, otherwise, there is nothing to gain beyond stock components other than reliability issues.
But good quality parts is a step up, such ans using NGK bran plugs and wires instead of some autolite or champion, and with the oil, you can consider different weights in full synthetic, such as 5w30, 10w30, 0w30, or straight sae30. The 5w and 0w can gain you fuel economy points, but the 10w will offer better protection at sustained highway speeds. The subaru engine can take anything from these weights, along with 10w40, 20w40, 15w40 and 20w50, depending on the application
The &n oil filter is nothing to marvel at, more brandig than engineering. Stick to a good quality WIX or napa gold series, mobil 1, or bosch filter, and for the air filter, stay with a paper filter for hotwire MAF reliability.
Edited by MilesFox, 23 April 2014 - 09:30 AM.