Sep WTI crude oil (CLU24) Friday closed down -1.12 (-1.43%), and Sep RBOB gasoline (RBU24) closed down -1.25 (-0.51%). Crude oil prices on Friday closed lower due to the week’s theme of weaker global economic growth and US political uncertainty. The markets are also worried on a longer-term basis about OPEC’s plan to trim its production cuts in the coming quarters. Crude oil prices gave back the gains seen on Wednesday and Thursday that were driven by a bullish EIA report and Russia’s promise of extra production cuts. Oil prices saw support from Russia’s statement on Wednesday that it plans to…