New to me Prius, not good mileage :(

I agree, you should just drive the car avoiding the typical mileage killers, like quick starts and late breaking. From everything I've read here, you take a mpg hit just by removing the wheel covers, especially if most of your driving is at highway speeds. You take another hit switching to 17" wheels and yet another depending on which tires you buy, Cooler weather affects the mileage as does the terrain, winds, traffic pattern, air pressure, etc. Using EV mode too much can also reduce mileage because the engine has to run more to recharge the battery. Traffic lights can reduce mileage, but the engine is off while stopped, so it's how you get back up to speed, not sitting at the light.

I don't have an explanation as to why the mileage wasn't much better, if any, when you still had the 15' wheels. It could have been the previos tires, the way the previous owner drove, low tire pressure, etc. My overall average is 47.7 mpg and most of my driving is also at highway speeds between 67 and 82 mph. My all-time low is 34.3 mpg between Ft Stockton and San Antonio TX (80+ mph) and I routinely get only 34-35 mpg through that stretch. I also get only around 39 mpg between Amarillo TX and Moriarty NM (75+ mph), but if Igo all the way into Albuquerque NM, the mileage goes up to 43 or so.

My point is your daily commute might just be through a section where it's difficult to get good mileage. That's why I'm curious to see what the per trip mileage is each time you turn the car off to see what mileage you're getting under different conditions and stretches of driving. I have a 15-mile route where I routinely get over 60 mpg where speeds vary from 25 mph to 30, 40, 50 and back to 25 with roughly half being at 50. Most of the 40 mph stretch is usually in EV mode and the battery does get depleted, but quickly recharges when I hit the next stretch. Unfortunately, there are other routes where I only get in the upper 30's, but most are in the upper 40's and it all balances out to give me in the low 50's around town and mid to upper 40's on the highway.

And I assume all the mileage numbers you've provided come from the display and not from maual calculations using odometer readings and gallons pumped. The display is ultra conservative and actual numbers are 5% or so less. I manually compute the mileage on every fill-up and use the display only as a guide to tell me if there might be a problem developing or something. At this point there may be nothing wrong and nothing you can do, but I think it's important to know what the displays are telling you, particulary regarding battery status, charging system status and per trip mileage. If your battery is not getting charged or holding a charge, mileage will be affected, but it's an indication of a larger problem.

I've asked a couple of times, but I don't think you've ever said what the battery status is at various times when you turn off the power. Starting the car in the morning and seeing the battery depeleted would concern me. And I'd be concerned too if it was depeted when I turned the car off after the drive home. I routinely check the battery status and mpg while I'm driving, mostly out of curiosity about how different stretches, speeds, etc., affect things.

 

Well, if the battery thing was only once, that's a different story.

I tried the EV thing too and was not happy either. I've actually found PWR mode to be more useful in heavy traffic, like through Houston. I spent 4 days in Houston last summer and experimented with PWR mode and it seemed like my mileage was marginally better the times I used it over the same routes. In each case, the mpg on the display increased during the commutes when I used PWR mode. Of course, traffic patterns weren't exactly the same, etc., so it was hard to tell, but having the car react quicker sure made the commute to/from ball games less stressful. Heavy traffic and high speeds don't bother me, but there's always subconscious stress.

 

for the record, i said LRR tires.

yap, common mistake of new prius owners.

i doubt if this is actually measurable. to put things in perspective, i get 45-48MPG @75-78MPH without the covers. I don't remember different numbers with the covers on.

 

My experience was the same, but that doesn't mean it can't be or wasn't measured in a windtunnel, etc. I can think of no other reason to cover alloy wheels than windtunnel tests showing an increase in drag efficiency, however marginal it may be in real world driving. If the wheels on the 2014 weren't black, I wouldn't use the covers, but I don't like the look of the Blizzard Pearl with black wheels and the 15" tires, and neither do my wife or grandsons. I had planned to switch to 17" wheels/tires, but I've given up that idea, mostly because I don't think they look that much better to justify the extra expense and whatever mileage hit there may be.

 

Now with the 2016 the 17" have plastic bits and are black.

 

And one of many things I don't like about the new model and have given up my plan to trade next year. Now I'm looking at 2020 and beyond, so there's no telling what will be available then, not only from Toyota and the Prius, but from others.

 

The odometer on your car is reading low and any gas mileage calculations by the car's computer or by hand are also low due to your oversized tires. I looked up the revs per mile for 225/50R17 vs 195/65R15, and you need to add about 3.6% to your mileage to correct the odometer. So 38.6 mpg with your oversized tires is actually 40 mpg corrected.

 

If you will go into the settings section you can setup the Prius to calculate that for you. It will do a maximum of six (6) months at a time. Just set the MPG for the Pilot and set the gas price you pay. Over time it will show up when you scroll through the various screens. Play with the "disp" button on the steering column and you should be able to figure it out.

You can also toggle (switch) back and forth between fuel cost and savings to see what you are saving each month and also how much you are spending each month. It is not down to the penny but rather a graph with lines that are separated in 25 dollar increments.

Here's a few screen shots of what I am talking about.

 

We're rolling on Michelin Pilot 215/45R17 about 9 months of the year, and 195/65R15 X-Ice through winter. The lifetime average, calculated, is at 4.9 liters per 100 km. That mouthful translates to 48 mpg US.

Our driving is a mix, pleasure-only, no daily rush hour slogs. I'm ALWAYS trying, my wife not so much, but she does care.

 

FoBW, the max. sidewall pressure is probably 51psi for your 17" tires. You should get better fuel economy and longer tread life by increasing the pressure. If you can, borrow a GPS unit and note the differences with your speedometer & odometer. As already mentioned, things aren't as bad as they seem--you just need better instrumentation.

If the battery display is losing bars between shut down & start up I'd be concerned or if the number of bars fluctuates quickly. I live on a residential street a mile or so from the highway. Depending on the weather I can make it home on the battery. Take a look at the Consumption Screen. You should see about 25mpg for the first 5 minutes as everything warms up. The second 5 minutes should be around 50mpg.

Get the feel of the car. There's a few quick, easy & cheap things that can be done to improve FE. Try driving in ECO, Power, and normal mode (push the button off). The butttons remap throttle response & the climate control. I stay in ECO.

Enjoy the ride.

 

I didn't look up the tires, but figured the size difference probably played a role, just didn't expect there to be that much difference in revs/mi. My Goodyear Assurance does 836 revs /mi whereas the Somitomo HTR Z III 225-50R does 808. On a personal note, I plan to switch to Michelin, so I'll go from 836 to 832 and from 16 to 19 lbs which will probably result in a slight loss in mpg, but only a very minor change for the odometer.

Even though the tires account for at least some of the low mileage, the mpg numbers are based solely on the display rather than manual calculations. I'm a stickler for checking things, so I'd be inclined to at least manually check a couple of tanks just to verify that the computer is working like it's supposed to.

As far as savings calculations, I use an Excel spreadsheet to track my data and based on the 24 mpg we got on the highway in our old van, we've saved at least $2,300 over the 48,000 miles we've driven. To be honest, that's about half what I expected, but who knew prices would drop so much and stay low? I would have entered the old mpg and used the built-in capability, but I like the what-if options the spreadsheet gives me.

 

Where was the state of charge when you first got to work? Maybe at 2/3's?

Likely that's normal, the outcome of prolonged idling.

 

I drive with A/C and headlights on so that is about right. It is hard guess your situation. without data.

 

I don't think that's normal at all, unless the battery was pretty close to low when you stopped. I drove to my wife's doctor's office the other day. It's a 12-mile trip of city driving with the AC running, temp was around 80° and engine was cold. It's 25 mph for 1/4 mi, then 30 for 1 mi and 40 the rest of the way. There are traffic lights every 1/2 mi, though I usually only get stopped at 1 mi intervals if I don't make the lights. I dropped her off and then parked. I left the engine running with the AC/radio on and I know it was over 20 minutes before the engine kicked in to recharge the battery. I always check the battery status before I decide to idle for long periods. The battery was at its normal level, 2 bars below full, when I stopped.

The next day we drove back to the hospital next door to visit her brother, but we took the freeway this time at 70 mph. Again, the battery was at its normal level when we stopped. I didn't idle this time, but have no doubt the experience would have been the same. We haven't driven the car now for 3 days and the battery level is still normal. Even in the middle of the summer heat here or the heat/humidity of Savannah, I can idle for a lot longer than 5 minutes before the engine kicks in and then it only runs for about a minute. I don't believe it fully recharges the battery, just adds about 2 bars, and then fully recharges once I drive a few blocks again. When driving on our trips, I pay attention to the battery status, but don't "record" exactly when it gets depleted. It seems like it only really gets depleted during long uphill grinds, the rest of the time it fluctuates 2, maybe 3 bars. I'll have a stretch today where it'll use EV mode for a few miles and I'll try to remember how the battery status changes. The 15-mi run is 1/4 mi at 25 mph, 1 mi at 30, several at 40 in traffic, then a few miles at 40 with no traffic followed by several at 50.

 

If it drops down to 2 bars when you idle. Why don't you not idle and just shut off the car? Either way it doesn't matter as the ICE will turn on as needed. If you had AC or the defroster running then it is normal to run to 2 bars in less than 5 minutes. Be aware that the feet and windshield position for the vents if on also run the AC.