[Ecky]

Cross-posting from the 70mpg challenge:

Originally Posted by Ecky

Today I drove to Boston to drop my brother off at the airport. Before leaving I played with ignition timing a bit, actually retarded it a few degrees in cruising range to try and smooth out some lumpy acceleration. Knowing I'd be in stop and go traffic I pulled my grille blocks off, since the heat index was over 100 degrees and I've seen on rare occasion the radiator fan not quite keep up when there's no airflow through the grille in very hot weather. I never have problems in Vermont, but I'm considering replacing or "upgrading" my radiator so I can keep the grille blocked more.

Driving there at 65mph with some air conditioning for his comfort and just leaving it in 5th, plus driving around the city in traffic for an hour, I averaged 41.5mpg.

On the way back I decided to shoot for the moon and see how close I could get to my current "realistic goal with some additional modifications and a careful foot" of 60mpg, with my previous best being 48mpg. My target speed was 50-55mph except for where coasting would allow for higher speeds. My underbody paneling is around 50% complete, my mirrors are currently in place (not cameras), and I did not have my grille block installed. For around 20-30 minutes I drove through some heavy rain. For around 2/3 of the ~4.5 hour trip (~222 miles) I held the stick in 6th gear, which takes quite a bit of resistance plus concentration/finesse with the throttle pedal, as pushing the throttle past a certain point throws it out of gear with basically irresistible force (until I take the transmission apart and figure out what I did wrong to cause this). 6th would likely climb any grade without a problem, but it seems like it's maybe ~25% load that throws it out of gear. Anyhow, 6th is good for a reduction in RPM of around 25% over 5th gear. On some of the longer downgrades (more than 15 seconds where the slope could maintain speed or accelerate) I key-off EOC'd. I did not use air conditioning, and had the windows down around halfway.

I counted mile markets for 100 miles and determined my odometer error is currently at 1.2% (my current tires at 1.3% larger than stock). After 222.0 miles I filled up at a pump I trust with 3.40 gallons, resulting in a trip fuel economy of 65.3mpg. I'm stoked. It's not quite 70mpg, but I feel like 70 is really attainable on some trips if I get a real kill switch, finish my underbody paneling, put my camera mirrors back on, reinstall the grille block and maybe add a few more PSI to the tires, which are at 48 front 45 rear right now.