i have alway's used WD-40 as a cleaner for my cars. it breaks down the dirt and oil left after playing and seems to restore old plastic parts that get brittle( for example after spraying nitro cleaner plastic parts stain white and are dried out, spraying the whole chassis with WD-40 and let sit about 10 minutes then blow and wipe off as much as possible you car will be like new) also clean's electric parts really good just my experiance, if this is wrong let me know if you dont have after run oil and dont plan on buying any then use WD-40 but if you care about your engine and want it to last a 3 dollar bottle of oil seems pretty stupid to question!