Crunching the Numbers: Week 2

I was a bit braver this week inflating the tires up to 40 psi but lost some ground in the fight for better gas mileage. My GoodYears list the maximum inflation at 40 psi so I doubt if I will go any higher although plenty of literature claims that inflating them much higher is quite safe and will lead to less rolling resistance and greater fuel efficiency. There was a noticeable degradation in ride comfort on rough roads but dry surface handling didn't seem to be affected at all.

Unfortunately, I had to make some trips out of the norm this week which disturbed my careful testing procedures and possibly contributed to the reduced fuel mileage average of 29. 21 mpg. Still at the very top of the factory fuel mileage ratings for this vehicle but now I'm hungry for more. I wonder if the expense of synthetic lubricants in the engine and drivetrain would pay for itself with less trips to the pump. The engine does have a small oil leak and I'm afraid that a slippery synthetic would just flow out quicker. Something to consider...