80 MPG in HV mode club

I wasn't able to hit 80 mpg (good job btw), but I did hit 77.3 mpg on a 317 mile drive yesterday which was mostly interstate and crossed some mountains on Vermont Route 9.

 

That was also starting with no charge.

 

How fast were you going?


iPhone ?

 

Here is the video of the attempt:

I averaged 51 mph, but I also went across the state of Vermont which is pretty much all mountains. On the interstate I kept it between 58 and 61 typically. I also made a point to pull over and let others pass me quite a bit, so that didn't really help my fuel economy either, but I didn't want to be "that Prius driver".

 

257 mile trip today starting from a full charge, ended up at 83 mpg. No net change in elevation
I drive slow, my wife does not ...

 

That's impressive. My net elevation change was +128 ft (according to Wolfram Alpha elevation figures). Did you increase the psi in your tires? Average speed?

 

I run the tyres at a bit below sidewall maximum.
Sorry, I didn't note the average speed but I tend to drive 60-ish and my wife is happy to drive 75 but my merciless stare usually keeps it below 70 mph.

My main advantage is driving at 5000 - 7000 ft elevation.

 

Long-ish stories made short-ish:

I generally do my best NOT to waste gas just to learn how little gas our Prime consumes as compared to other cars, but... with about a half-charged battery, I have done two "tests" in HV around town. One... 21 miles... three stops... about 71.4 mpg per the car's readout. Two... 17 miles... two stops... about 74.1 mpg per the car's readout.

Also... a trip to-and-from Indy several days ago... 121.8 miles total (196 km)... a total of about 18 miles (29 km) in "pure" EV mode (in-town driving PLUS when accelerating to highway speed AND when slowing for exit ramps and such) ... the rest in hybrid mode... and the *car* "thinks" it consumed about 1.59 gallons of gas / 76.9 mpg... consumed about 6.0 liters / 3.06 l/100km.

Not 80 mpg to be sure... but PIPPPIN gets MUCH better mpg than MITHRIL (our '08 Prius) ever did... which was maybe up to 65mpg around town in ideal traffic and weather conditions, and maybe as high as 61mpg on road trips.

SO FAR: PIPPPIN is averaging about 87.5 "literal" MPG after about 2500 miles... meaning, it has been driven 87.5 miles for every gallon of gas (28.3) that it has consumed. (It's been plugged-in a total of about 150 hours since purchased nearly three months ago.)

 

WOW... ... that sure beats my meager 76.9 mpg over a mere 128 miles... ... CONGRATS TO YOU!

 

I recently passed 3K miles. I have a lot of EV miles but I also have three 550-600 mile non-stop HV trips @ 70+ mph. With that in mind, my hand calculated trip cumulative average is 120.581 mpg over 2,889 miles. My average cost per mile is $0.0201. This includes charging @ $0.06 per kWh and gas prices around $2.50/gal.

Compare that to $0.057 avg cost per mile over 105,000 miles on my sold 2010 Prius II, and $0.0664 avg cost per mile over 30,000 miles on our 2014 Camry Hybrid, and $0.1043 avg cost per mile over 27,000 miles on my 2014 4Runner TEP. Note these three vehicles saw gas prices in the $3.50's for quite a while skewing the cost higher.

I remain impressed with the Prime.

 

120.581 mpg? I find that amazing... especially since that average involved such lengthy / HV road trips!

BUT... how do you determine your TOTAL average cost per mile... I mean including the cost of your kWh consumption? How do you determine your cost for the time you're Prime is plugged in? I've been keeping track of how many hours our Prime has been plugged in (152)... and the price DUKE charges per kWh ($0.092 (*) / (*) $0.054)... but would I then simply multiply the number of hours plugged in by the indicated price per kWh? I mean... is the cost that easy to determine? Or is there something else I need to take into account to determine the cost of plugging in our Prime?

Actually... I'm inclined to take the TOTAL amount due, including "Connection Charge"... taxes... "Riders", divided by the number of kWh consumed as our ABSOLUTE cost per kWh...

...as an example... from our October bill: TOTAL amount due ($96.44) divided by kWh consumed (701) equals $0.138 per kWh.

And lastly (you hope... ...), like MANY others around here, we ALSO remain impressed with PIPPPIN... our Prime / Premium!

(*) / (*) "...$0.092 / $0.54...": The cost per kWh is "tiered"... depends on our total consumption in any given billing period.

 

Are you using the bundled Toyota EVSE ?
I think it draws 12Amps at 120V, so an hour would be 1.44 kWh consumption from the meter. The car battery of course ends up with less due to OBC losses, etc that waste ~ 20%

Example:
152 hours is 152*1.44 kWh
If a kWh costs $0.092, then 152 hours of charging costs 152*1.44*0.092 dollars

 

I keep a spreadsheet of fill-ups (and charges) which computes trip cost per mile and total cumulative average cost per mile. I know that a maximum charge is 6.25kWh, which I always do. So 6.25 kWh X $0.06 per KWh all inclusive = $0.37 per charge (worst case). I know how many times I charged during that tank mpg calc and that EV cost is added to the HV cost / number of miles. Yes I could track the EV kWh much closer but it's just not worth it. I virtually never do a partial charge.

These are impressive vehicles. It's also mathematically impressive how 30 miles of EV only 4 - 5 times a week can add up to offset a lower mpg long trip during the same mpg calculation time frame.

 

Just so you feel better, that mpg cumulative average is coming down. Three fill-ups 186.776, 147.919, and last 120.581 cumulative averages. Colder weather, more road trips, and heavy traffic, are all bringing it down. The traffic is killing me lately. I just can't (won't) drive like I "want" to in traffic to get the high mpg's. It's the acceleration part that's killing me. There's no way I can accelerate that slow and not interfere with traffic. The glide and stop portions are great.

 

As Mark57 says, these cars are the penultimate hybrids, and in terms of value make every other car look expensive.
I mostly drive either 90 or 250 miles between charges and my lifetime MPG over the past ~ 8 months and 12k miles is 105 MPG.

My EV miles are fueled by home PV which is too cheap to bother calculating on the fly, but I know I pay about 0.5 cents an EV mile

 

PS, I forgot to mention that I only burn E0 (100% no-Ethanol gas) in the Prime. It runs about 20-25 cents higher per gallon so my cost per mile "could" be even lower if you just looked at $ spent. The crux is I get much better mpg with E0 so it offsets the extra cost in the end.

 

In California, probably as in many places, the ethanol is 10% now, and mpg definitely goes down with it (I had been trying to hypermile in my Civic Hybrid during the switchover, and immediately knew when the formulation had changed with the 2 gas brands I use).

 

We have E10 and E85. I used E10 if I have to on the road. I can always tell when the new winter formulation gas is delivered because mpg goes down.