First tank over 50.

You will get a better boost in mileage if you drop the higher octane fuel (a waste of money) and instead find a station that sells 100% pure gas, no ethanol included. My mileage shot up 5mpg and I've been using it ever since. Also, you might want to raise the pressure in your tires. I happen to go 39 psi all around and the tires also wear better. Use cruise control when you can as the computer will do the easy driving for you. Anticipate red lights and get off the gas early when coming up to one. Coast down off ramps and stay with the speed of other traffic on the expressways. Have a nice day and God bless.

 

Ethanol is actually recommended. Decades ago, I too used Gumout. It was to help remove water from the system. Ethanol does the same thing. It, along with the usual cleansers included in gas nowadays as well as the PZEV setup for Prius, covers the rest. Since ethanol blended gas has been the only type of fuel available here for over a decade now, this is quite thoroughly proven.

My average all summer long has been in the low 50's, which includes a routine cruise at 70 for my daily commute. Using the lower octane gas and bumping up the PSI in the tires (44/42 for mine) is what I recommend.
.

 

1. Synch your accelerations with a downhill grade when possible so most of your speed gains are created when you are going downhill.

2. In continually hilly terrain, speed up before climbing a hill and gradually drop speed as you get to the top of a hill.

3. If you have to stop at the bottom of the hill, dont use any gas or electricty, but allow gravity and momentum to push the car downhill and use regenerative braking early during ride downhill to maximize the HV battery recharging session. My experience is that the most efficent recharging level is done when the Prius is going over 25 mph and the recharging level is about 75% to 50%.

4. If you have to start from a stop at the bottom of the hill, if the SOC of the HV battery is higher than 50% set the mode to EV - press the accelerator accelerating quickly as you can to a speed over 26mph (the electric motor will turn off and the ICE will immediately take over ). if the SOC is less than 50% - in ECO mode press the accelerator lightly with the with the HSI on the left side of the ECO so that only the electric motors are starting and accelerate up to 7 to 10 mph using electric only then press the accelerator moderately using the ICE to accelerate over 26 mph. If the hillgrade is over 10+ degrees and/or 100 yards long then accelerated moderatedly over 12mph over your target speed that you want to be at when the car is at the top of the hill. After achieving your top speed, gradually reduce pressure on the accelerator to give up the additional 12mph you've just built up as you climb uphill so that you get to target speed at the top of the hill.

5. Avoid going over 55 mph. Here are two ideal scenarios for max fuel efficiency on a 2010 Prius.

A. You are the only car driving on a smooth multilane (driving on the right lane where there are 2 lanes for each direction) slightly hilly to flat suburban/rural roads with few stops, your speed is from 25mph to 38 mph( the posted speed limit is 30mph), temperatures around 70 degrees fahrenheit, AC off windows rolled up, defroster/heater off, Tire pressures set to +42psi front / +40psi rear, route/trip is atleast 30 minutes and more idealy 60 minutes long, no crosswind, and no precipation. Using 100% gas. Hypermiling technique: Driving without brakes, using pulse and glide.(goal 65 to 80 mpg calculated at the pump/ MFD may read +70mpg or more, on a particular route one way you might get +80mpg)

B. You are driving on the right lane of a lightly travelled multilane ( 3 lanes going each direction) highway road with no tollstops, driving around 50 to 55mph(the posted speed limit is 55mph), temperature is around 70 degrees fahrenheit, AC off windows rolled up, heater /defroster off, tire pressure set to 42psi front and 40 psi rear, entire trip is about 120 minutes to 360 minutes long (no stopping at the rest centers) Using 100% gas. Hypermiling technique: Driving with Load. ( goal 65 to 70 mpg calculated at the pump, MFD/scanguage may estimate a higher mpg of +68mpg, )

6. Minimize the Prius's ICE autorun cycles. The Prius fuel efficiency drop significantly when the ICE turns on automatically. These ICE autorun sessions force a 15 mpg to 30 mpg drop during the first 3 to 6 minutes after a cold startup when the Prius warms up. During the winter (when the outside temperature is less than 40 F during the entire trip), a MPG drop of about 5 to 10 mpg occurs when an intermittent ICE autorun may occurs to push the coolant temperature back up to about 170 F degrees. In addition, when the Prius HV battery State of charge (SOC) drops below 40% (3 bars) the ICE will turn on automatically to recharge the HV battery to a SOC of 50%. Again - this auto run session forces the MPG back down. I use a ScangaugeII to monitor the Prius coolant temperature - when the coolant temperature drop less than 140 F - I use the ICE more frequently to get the temperature back over 160 F (181 F is the optimum coolant temperature) and I do grill blocking when the outside temperature drops below 50 degrees Fahrenheit. I use the ScangaugeII SoC Xgauge to monitor the HV battery's state of charge because its more accurate.

 

In addition to Walter's post I would add that you do not use the AC, just roll your window down and crack the passenger side rear window a bit to reduce wind/cabin oscillation noise. Or use the AC but keep the temp setting high at 78 or above. The AC really drops mpg, especially in the city.

 

The challenge in hot weather is not keeping the
driver cool but to avoid having the HV batteries
from overheating - to avoid prematurely aging
the HV battery pack. The 3gen Prius use air
intake vents to take air from the passenger cabin
to cool the HV battery located behind the rear seats.
There's an on-going debate about how hot the
passenger cabin temperature should be before
it will or could adversely affect the lifespan of
the HV battery - Because the 3rd gen Prius
air intake cooling vent for the HV battery is
next to the passenger/right side rear window
- when it gets hot - often I'll open the right side
rear window first if I think the ventilation will help
the traction batteries - otherwise if its really hot
outside - I'm more likely than not to just
rollup all the windows, turn on the AC, and
bite the MPG bullet - so I can protect the HV
batteries from overheating. While I have a
ScangaugeII and I could monitor the
traction battery temperature and turn on
the AC before it gets too hot - I have
first have to figure out what that tipping
point temperature is.

 

The biggest difference OP made is slowing down to 65 mph. More attention is needed to hit 65 mpg, and past that, well -- you know who you are

Btw, this week I started seeing 70 mpg round trips again. AC is still used, but the load is much lighter now that some clouds have come to town.

 

I agree with you both.

TheMpg hit from AC use is pretty low unless you are running it on max cold on short trips or in the city.

 

Hertz rental Prius, 3 people, luggage for a week, lots of goodies stacked to the ceiling and under the seats. 45psi in all tires, 87 octane Wisconsin gas, 63-70 mph down US-8 swerving for deer, raccoons, 2 cats & 1 coyote. Nothing special about my driving other than staying awake late night



The Hertz rental Prius at Lake Michigan earlier in the day.



Trip average after a week of traveling a couple mph over the speed limits and also some 85-98 mph cruising in Northern Michigan up I-75. Pretty darn close to 50 mpg. Ran the A/C all the time set at 72 degrees.



Mike

 

Your AC is likely not working very hard, even in the city. With recent highs in the high 60s low 70s you are not subject to the heat like those of us in Northern Cali or Texas.

 

Are there others getting consistent over 60?

last 3 tanks, 600mi+/tank, current MPG 65.4 for 150mi, avg MPG after last oil change (5340mi) 60.5

 

do you even need A/C in Bay Area? It is dry and never gets hot, really :target:

 

Monterey is not consider part of the Bay Area. It is, however, MUCH cooler than in the interior portions of California and half of the Bay Area and from my experience rarely requires the use of A/C. Monterey is very foggy and misty at times so I would not really call it dry. Ask some fo the women who live there what it does to their hair. lol