Well, with the Jimmy out of commission for the time being, I have the White Gnat (1999 Suzuki Swift) back, but it's not too happy. It needed a new alternator & battery, but after that, wouldn't even idle without dying. So I "SeaFoamed" it today & put 100 miles on a fresh tank of gas (and SeaFoam) to try to clean things out, maybe. By the end of the drive, it would idle in neutral, at least.
In MPG vs. speed tests, with a yet uncalibrated ScanGauge, I had to drop it below 60 mph before it would hit 40 MPG. And I was unable to do an 80 MPH test because it wouldn't go that fast. !!
Anyway, taking it into my mechanic tomorrow for a compression & leakdown test.