Tag: gas mileage

Post #1714: Ah, crap, another 80 MPG trip.

 

I am presently recovering from a severe shoulder sprain.

It was self-inflicted, the result of patting myself on the back too hard.

The problem starts with my wife’s Prius Prime.  It has more-than-met our expectations in every respect.  In particular, as-driven, it typically exceeds the EPA mileage rating, either on gas or electricity.

Lately, I’ve been trying a few techniques to try to squeeze some extra gas mileage out of the car.  Just some around-town trips, driving it to try to keep the gas engine in its most efficient zone.  Which, per Post #1711,  boiled down to fast starts on gasoline, followed by coasting on electricity.  Below, that’s an attempt to stay on the top of the green efficiency “hill”, followed by keeping the gas engine off while driving in the aqua “EV carve out” zone.  (The labels on the contour lines are “efficiency”, the percent of the energy in the gasoline that is convert to motion.)

Results were encouraging.  A couple of test trials showed mid-70-MPG for a series of trips and test runs, entirely on gasoline (using no grid electricity).  Given that the car has an EPA rating of 55 MPG for city driving, I figured I was doing something right.

But at some point, it dawned on me that

  1. the current EPA mileage test is based on the typical U.S. driver (i.e., somebody who drives like a bat out of hell, whenever possible), and
  2. I have no idea what my “typical” city mileage is, because I almost never drive the car, around town, on gasoline.

In short, I made a classic mistake of trying to do an experiment without a control.  I had no baseline to which I could compare my results.  I literally didn’t know what mileage the car would get if I wasn’t fooling around with the accelerator pedal.

I decided to find out.  Yesterday we took a trip out to my sister-in-law’s and back.  About 15 miles, mostly on 35 MPH suburban roads, rolling hills, no traffic to speak of.  Gas only.  Didn’t need the AC or the heat.  Relatively few stop lights.  Driving normally.  (But acknowledging that I’m a light-footed driver by nature, and that monitoring the car via a Scangauge 3 has done nothing but increase that tendency.)

In short, reasonably close to ideal conditions for a trip.

Results:  The odometer clicked over to 80 MPG for the trip, just as we were returning to our driveway.

I am reminded of the following medical advice:  If untreated, the common cold will last a week.  But with proper medical attention, you can expect a full recovery in just seven days.

Thus it would appear, for urban hypermiling in a Prius Prime.  As-driven, 80 MPG, for my suburban area.  No fancy footwork required.

Post 1621: Look ma, no battery!

 

Or, “why I truly don’t give a 💩 about high gasoline prices in the U.S.”, the sequel.

Back in June of this year, in Post #1454, I explained why I didn’t give a 💩 about the price of gas.  In a nutshell, I don’t use much.  I drive my wife’s Prius Prime.  The 30-mile battery range covers essentially all our local travel.  One we’ve run through that, the gas mileage is outstanding.

The genesis of the prior post was our annual trip to Ocean City, Maryland, where the car got 72 MPG on the highway.

I figured it was a fluke.  There were no hills to speak of.  We probably caught a tailwind.  Unlikely to be repeated.

Today we went leaf-peeping, driving from Vienna VA to Sperryville, VA and back.  There is just something about the autumn scenery in central Virginia that my wife and I both love.

(Best sign seen on the trip:  “God Allows U-Turns”.  This, at the exit of the parking lot of a little church in Sperryville where we were — yeah — making a U-turn.)

The trip was a combination of interstate highways, then primary and secondary highways traversing hilly terrain. It was a nice drive — once we got off the interstate.  I reset the odometer after the battery was depleted so that I could check the gas mileage.

Lo and behold, in round numbers, 72 MPG.  Straight-up gasoline-powered transport, no battery.  Completely different terrain, time of year, and driving conditions compared to last time.

So, no fluke.  I’m not drafting trucks. I’m not doing 35 in the right-hand lane.  I’m  just keeping up with traffic, and paying a bit of attention to instrumentation on the dashboard that offers guidance for best fuel economy.  (And it didn’t hurt that we didn’t need AC or heat for this trip.)

It’s odd how your expectations change.  These days, if I come in under 65 MPG for the gas portion of a trip, I’m disappointed.

This is not as clean as a pure EV of the same size.  At least, not as clean, at Virginia’s current electrical generating mix.  But it’s not bad for the latest refinement of a gasoline-based technology that Toyota put on the road more than two decades ago.  And the same drive train that gets us 72 on the highway allows us an effortless transition to electrical transport for all our around-town driving.

For us, this plug-in hybrid electric vehicle (PHEV) is absolutely the sweet spot in the spectrum of what’s on the market today.  After a year of driving this car, we have no regrets about buying it.