I copied the following results from todays commute off my scangauge:

Morning leg (departed 4am, outdoor temp 53 degrees, minimal-to-no traffic, timed almost every traffic light, cruised with windows up and no A/C):

• 40.8 MPG
• 0.9 gallons used
• 195 degree water temp max
• 36.0 mile trip
• 2818 RPM max
• 0.7 hours
• 64 MPH max
• 46 MPH avg

Afternoon leg (departed 2pm, outdoor temp 78 degrees, heavy traffic, got stopped at almost every traffic light, windows up and A/C blasting):

• 43.5 MPG
• 0.8 gallons used
• 193 degree water temp max
• 35.2 mile trip
• 2835 RPM max
• 0.7 hours
• 61 MPH max
• 45 MPH avg

What gives - how did I manage to get a higher computed MPG reading on my return leg with heavy traffic, stopping for many lights, and the A/C on?

You probably drove slower on the highway if you have highway in your commute.

My hydroponics experiment

You ever notice how hard it is to lip read cartoon characters?
"Crazy is what the sane call Delta Flyer"

hmmm.... half of the commute is on interstate 66, the other half is on Route 7100 which is a 50 MPH four lane highway, with a large number of traffic lights intermixed in the approx 16 miles I'm on it.

I really felt like I held the speeds pretty close for both legs (55-60 MPH on I-66, and 45-50 MPH on 7100).

Your stats show a 1mph difference in the average for the latter drive.

My hydroponics experiment

You ever notice how hard it is to lip read cartoon characters?
"Crazy is what the sane call Delta Flyer"