(2 Crown Vic mileage drop off
I have a 92 Crown Vic LX in great shape with only 63000 miles. I have had it since 9000 mi and it has been a very good car however, I have noticed recently that the gas milage has dropped off 3-4 mi a gallon. I could try changing the plugs as they have been in it for 50000. they are Boesch single prongs. I have also noticed a slight “lugging” at lower rpm ranges in the highest gear. I also have a clean K&N air filter. I use reg unleaded, change the oil regularly with synthetic and have also used slick 50 when I first got it. The car does not receive any dealer maintenance but, I do keep it up well. I was wondering if you knew of any such item that should be done such as valve adjustment or anything which might contribute to my concerns. I am also wondering could it be the intake air temp sensor. If anyone has any ideas please let me know,,,Thanks.