My '98 S70 is about 106k miles now. A mechanic friend told me all it needed for 100k maintenance were things like oil/filter change, fuel filter change, transmission fluid change, and new spark plugs (all done).
However, I'm wondering if I missed anything like engine timing adjustment or any type of adjustments?
I ask because over the last 8 months my gas mileage has been dropping from 23MPG to 19MPG (87 gas always used) without change of driving conditions or habits. Such drop also conincided with the time when then odo reached 100k.
Adding of fuel injector cleaner didn't help.
What should I do to bring the gas mileage back?
Thanks!