I have been having a odd issue with my daily driver. It's a 1995 escort with a 1.8 and around 205k on it.
My MPG seems to vary every other tank. Meaning one tank I get 22-24 mpg and the next tank I'll get 33mpg. I averaged 33 mpg for around 3-4 years before.
The car has recently had 4 new plugs and wires. Doesnt show any signs of running weak on power, fuel filter is a year old. Car gets 89 octane and I use the same gas station/pump for each fill up.
It's very odd because it is literraly every other tank. I go 23mpg/34-36mpg/23mpg/34-36mpg.
I have looked for leaks and havent noticed anything. This has been going on for awhile, and before I moved so I doubt anyone is actually taking gas out of it.