Crude oil prices slogged higher Wednesday with prices at the lower end of an $88 to $92 plateau that has been steady since mid-July. Markit manufacturing reports from Europe and Asia showed sharp slowdowns as factories in most of Europe remained in recession. Support came from China, however, where President Hu articulated his support for economic stimulus. West Texas Intermediate crude oil prices climbed on the New York Mercantile with September delivery contracts gaining 83 cents to $88.89 per barrel. Reformulated blendstock gasoline added 5.37 cents to $2.828 per gallon. Home heating oil gained 0.85 cent to $2.8565 per gallon. Natural gas was at $3.153 per million British thermal units, off 5.6 cents. At the pump, the national average price of unleaded gasoline added 2.1 cents overnight to $3.521 per gallon, AAA said.