In Dec 2022 I bought a 2005 V6 Hybrid with 55K miles. Right now it's only getting 24 mpg in the city. I drove it 120 miles or so on the freeway recently and got 33mpg. The Carfax Report doesn't show it ever got the spark plugs replaced. Are they the kind that last 100K miles or are they the kind that last 30K miles? Any ideas on why it's getting low mileage? The Carfax Report said nothing about the Hybrid battery.