Got my new pulley installed. I needed a new belt as well, and decided to go with one that had one fewer rib (6 vs 7) while I was at it. The belt's effective length was 66 inches, but I would probably have picked out one @ 66.25" if it were available.
Preliminary results:
Earlier this week I had a commute where the outside temperature was nearly 40F. The roads were damp, but clear. Nobody was on the road, and I was able to maximize EOC I arrived at work with 53mpg on the gauge.
This morning it was 26F. The roads were a bit slushy. There was some traffic, and I wasn't able to EOC nearly as much. I arrived at work with... 53mpg on the gauge.
Yesterday after swapping out the pulley, I made a trip to and from my local auto parts store, to return a belt I didn't need. I averaged 55mpg on the way there, and 56mpg on the way back. I don't think I've beat those numbers on that trip, even in the height of summer.
It's tough to draw any conclusions based on such limited data, but I know for certain that my biggest single waster of fuel is the "minimum load" or parasitic drag from the engine - it's relatively thirsty even when idle, and that caps my maximum achievable fuel economy without heavy EOC at around 65mpg. This is the sort of mod that helps with that.
