1993 Ford Probe 4 cyl Front Wheel Drive Automatic 162000 miles
When I got my 93 Ford Probe in 2004 It was getting around miles 36 per gallons highway and in city 30. Now it is getting highway about 26 and city 21. It doesn't need a tuneup. It has good compression, good plugs and wires. Engine light does not come on. I checked mileage with interstate mile markers. What could be cause such a difference in the mileage?
Cars do become less efficient over time, just a natural occurance from the wear on the engine. Have you changed tire brands? Try checking the tire pressure, most tires nowdays use a 44psi suggested inflation, others are as high as 51psi. Tire underinflation is the#1 cause of mileage loss. Also front/rear end alignment will cause loss of mileage due to excessive tire friction