1985 olds , 6 cyl, great and all originals but now is performing at 10 miles to 1 premium gallon vs. past 15 in the city , WHY ?
Tune up, sparks set at 0.060, oil,filters,cables,gas and air filter new perfect one touch and stars , but why is now at 10 miles to 1 gallon of premium vs previously 15 to 1 gallon ?