What should my gas mileage be after replacing PCV valve?
What should my gas mileage be after replacing PCV valve? A mechanic suggested replacing the pcv valve with one from the dealer. It helped a lot, but gas mileage is the most affected. I used to consistently pull 34-38 mpg. Now, 29 around the city and 33 highway. I always check mileage after I change a part to see if it did anything. What causes the RPM to go up or down? While cruising at any given speed, I will come to a stop sign or red light or a situation that causes me to take my foot off the...