Greenville, MI Zip Code 48838 Lowest Regular Gas Prices Summary. There are 11 Regular gas price reports in the past 5 days in Greenville, MI Zip Code 48838. The average Regular gas price in Greenville, MI Zip Code 48838 is $2.49, which is $0.09 higher than U.S. national average Regular gas price $2.4. The lowest Regular gas price is $2.46 of CITGO located at 1325 W Washington, Greenville, MI 48838.