On August 16, at 0940 central daylight time, a Cessna 182C, N8643T, collided with the terrain during an off airport forced landing in Sparta, Illinois. The pilot and passenger were not injured. The airplane sustained substantial damage to the firewall. The personal flight was operating under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed. The airplane last departed the Danville-Vermillion County Airport (DNV), Danville, Illinois, at 0845. The pilot reported he originally departed Warsaw, Indiana, at about 0730 on the morning of the accident. He stated the airplane contained approximately 45 gallons of usable fuel. He stated that during the flight the "service oil filter screen" light illuminated, so he diverted to DNV. He stated he removed and cleaned the oil filter screen, and changed the oil prior to departing for the Sparta Community Airport (SAR). The pilot stated he began his descent into SAR using 15 inches of manifold pressure, and when he reached traffic pattern altitude he attempted to add power to no avail. He stated the fuel gauges were indicating that he still had fuel and the propeller was wind milling prior to it stopping. The pilot initiated an off airport landing in a retail parking lot. The nose gear separated from the airplane resulting in firewall damage, and the left main gear collapsed when the airplane impacted the ground. The airplane then slid into a ditch where it came to rest. Post accident inspection of the airplane revealed that it came to rest with the right wing higher than the left wing. The right wing did not contain any fuel and the left wing contained less than four gallons of fuel. The gascolator was separated from the airplane due to the impact, and there was no evidence of fuel leakage at the accident site.