Excellent MPG even w/ winter gas - why I love this car

I'm beginning to think winter gas is a myth too and the cold weather has more to do with poor gas mileage. I do full grill blocking and hood/fender seam blocking, 50% top grill, 95% bottom grill (I left the small slot where the outside temperature sensor unblocked) and 100% hood seam. There's a 15 mile round trip route that I frequently take. If I drive that route in the early morning or late at night where outside temp is around 35-40F, I get 50-52mpg, 55mpg if I'm lucky. This is without turning on the heater. I only use heated seats occasionally. Taking the same route with the same gas during the afternoon where the outside temps at 67-72F, I get 60-65mpg. I get the same mileage during the summer nights without grill blocking and no AC. 55-60MPG during 105F summer days with AC on.

 

My apologies to all...I was thinking speed limit when I wrote my post. The 44.7mpg was at 70, not 75 (stayed a little below limit) and a few miles around the town I went to at fairly low speeds. In fact, I was really impressed how long I could "cruise" at 35 with the display showing 100+mpg (assume that means full electric).

 

dstrauss, your results are about right. I got 63.5 mpg for 140 miles recently in my 2010. That was mostly interstate at 58 mph (psl 70 and 75), elevation gain of 600 feet, but a nice tailwind. That 63.5 is really 60.3 due to 5% overreport of the gen3 when measured at the pump.

 

Oh wow - you are a better person than I Gunga Din! I couldn't drive 55 when it was the law of the land. Besides, out here on the flats of West Texas, you are very likely to get steam-rolled by an 18-wheel oil tanker of you try that, even on the four lane interstate...

 

That's ok, it's still not too bad for 70 MPH

Yeah those slower trips can really increase your average. My commute involves more of this low speed driving than high speed and under those conditions 50+ MPG is actually pretty easy in this thing.

 

While usually true, that is not a definitive indicator of full electric propulsion. An engine monitor such as ScanGauge sometimes betrays gas burning operation with MPG in the 100 to 300 range.

 

Three days ago I went on a 115 mile trip to see DH. I had to fill up after about 30 miles. When I completed the trip, it was close to 57 mpg on the screen for the new tank. I drove at 65 mph and the temperature was in the 40s (or 30s perhaps). No grill blocking and tire pressures were set to 40/38 few weeks ago.

 

My initial familiarity with 'winter gas' came from a relative responsible for blending fuels at a refinery, a quarter century ago, and she indicated that the difference was very real. But neither of us were fully aware of the impact of the other factors.

One fuel indicator should be density. Back then, when virtually everything in the blend provided energy, summer fuels were clearly more dense. The difference was great enough that some independent haulers who didn't pay attention to their notices about the fuel change in the spring were snagged for overweight loads at the nearby truck weigh station.

Fuel blend requirements have changed over time, with more non-energy oxygenates in the mix, so density changes might no longer be a good indicator for how much of the winter MPG shift is due to the fuel itself.