I kept a detailed record of the gas usage and mileage on my Camry when I drove longer miles before. At these days, I drove slowly at 57-60 MPH and I got an average of 37.61MPG for a period of 1 year and 2 months. It was roughly 25% road and 75% highway driving. Then I didn't record the mileage for about 2 years. I started recording the mileage the last half year since I travel between 2 cities frequently. My MPG has dropped to 32MPG in average with roughly the same 22% and 78% highway. I also noticed that the way to get a higher gas mileage has changed. The ideal speed used to be between 55-60MPH, but now it needs to be a little over 70MPH.
Compare the MPG at different speeds (from a trip of ~160 miles):
62.5MPH - 29.49 to 30.11 MPG 70 MPH- 32.95 to 33.46 MPG 72 to 73 MPH- 33.19 to 35.56 MPGSo basically, the faster I go the less gas I use as opposed to the old days I got more driving at 57.5MPH. I never tried faster but I think MPG would drop if I go faster. The only thing I can think of is that I changed the spark plug which is Bosch 2 ground electrodes before I started recording my mileages this time instead of the 1-electrode ones that I used before.
So do you think that different spark plugs generate different gas mileages and it has different optimal performance at different speeds? I've not changed my gas filter to tell if that makes any difference.
My car is 1994 4 cyl. Camry with ~108,000 miles on it. It had 60K to
70K miles on it when I recorded the 37.61MPG.Any suggestions on getting more MPG out of it. It still runs well, and I hope to get another 100K out of it.
Thanks,
cpliu