Lately I've made a few posts in here regarding the horrible gas mileage I was getting on my 01 Accord. Between the research I did, the suggestions I received here, and the knowledge of my dad, I think I have everything fixed. I had a CEL for my Thermostat so I went ahead and bought a new one to see if that would help. The rubber seal on the original had partially deteriorated and looked like it was rusting. Replaced it and my CEL was fixed. My car seems like it heats up much more efficiently now, but I won't know for another day or two when I do a bit more driving. The heater itself on the car definitely seems to have improved, and whether that was a result of me changing the thermostat or not, I'm not sure. Went ahead and replaced my spark plugs and wires, distributor cap, and rotor as well. The cap and rotor had minor wear, and were probably fine to have left alone but they were cheap and I was re-doing everything else so I figured I'd do them too. All of the spark plugs were creaky when I pulled them out due to the lack of anti-seize. One of them was actually somewhat loose and looked like I was probably losing compression on that cylinder. I think my dad said it was called blowby. Overall it was a great learning experience and I'll be sure to post my updated mileage in the next week or two to see how things have improved. Cliffs: Replaced thermostat that had deteriorating seal, had bad compression on one cylinder. New plugs/wires/cap/rotor. Will post updated mileage log after I drive a bit. Very excited.