2015 Prius Trim 2 subpar MPG

maybe you are driving too slow. are you trying to keep it in ev?

 

Was it raining? I am amazed how much water on the road changes the rolling resistance and drops the mpg. Everyone knows that closer air is more dense when it comes to flying an airplane but is it enough to increase the drag driving down the highway at 65 miles per hour?

 

absolutely.

 

That all sounds about right. The big factor is your speed. 76~79 mph in the dead of night: is that mandated? What's the posted limit. That translates to around 125 km per hour, something I'd feel uneasy about, in perfect weather, daylight. Look up graphs of speed vs mpg. On a secondary highway if you have to, try 50 mph, see what you get. I'd think the low to mid fifties (mpg).

 

As you slow down it ticks up dramatically though. As I said before, try 50 mph (80 kmh), and see if you're not in the low to mid fifties.

 

You should probably wait until the weather gets warmer before you decide your car is underperforming. A number of factors are likely contributing: temperature, speed, winter gas formulation, among others. I find I get better mileage when I don't use cruise control. Also, how windy was your drive between SF and LA? (My worst tank ever was driving 70 mph with strong headwinds and temps in the 30s: averaged 35 mpg.) Even though winters are a lot colder in the Midwest, my 2011 and 2015 Prii average low-40s mpg in the winter and low-50s in the summer.

 

Headwinds are like uphill grades. Both drop mpg due to simple physics, it takes more effort to move the car. And higher speeds are somewhat comparable to headwinds.

 

I think you are just over reacting for not getting the EPA rated 50mpg from a very good looking 48mpg. We had listed some of the factors like driving conditions, temperature, tire pressure, driving habit, most importantly speed. Like someone suggested (sorry, at the time of typing I forgot who did), wait until a warmer month to find your "baseline" to compare to. January isn't a very good time to find your typical mileage because it's usually colder, wetter, windier, and having winter blind gasoline the gas mileage surely suffers.

For myself, I drive mostly on the usually flat hwy880, it's been cold and wet with storm after storm for most part of Dec and Jan, my calculated mpg went from 51 to 47 during the past 2 months. See graph on post #19 (I don't know how to post my Fuelly icon here like lots of members do). It's normal, mpg goes up and down with seasonal changes.

I really think you are doing pretty good and you can just relax and enjoy driving your Prius. Nothing is wrong with your car, it's not a lemon. With warmer weather and summer blend gasoline you sure will have better mpg. Help us to help you more, set up a Fuelly account, upload all your gas fillups, and then you can share more info with us.

Hope this helps.

 

[QUOTE="Phatlife, post: 2474445, member: 148901"power mode will only last till the battery drains out, then you back on the engine [/QUOTE]

What ?? the power/normal/eco mode has NOTHING to do with battery simply put only re-mapping your accelerator pedal. i.e. what the car "thinks" you are want to do sensing the movement of the pedal. So if you floor it in ECO mode you have the same thing (if battery low of course no help from there either)

 

^ There can be so much misinformation tossed out, it becomes pointless to attempt to correct it, lol.

 

I had a very similar story. My 2012 was totaled in an accident & I bought a 2013 replacement. In the 2013 the HV mileage was way worse than I was used to I tried new tires, replaced the worn and dragging brakes, changed the oil, replaced the air filter, replaced the 12 volt battery all yielded negligible improvement. In desperation I bought a can of Mass Air Flow sensor cleaner ($7.00) and cleaned the MAF, a 10 minute DIY job. Presto as if by magic I got my old car back! I'm still gathering data but it looks like my HV mileage has gone from 46 to 55. Even though your car has only 10,000 miles I recommend you get the appropriate cleaner and clean the MAF sensor. You may also need to replace the air filter.

 

There was one guy here who might have toasted his MAF due to frequent cleanings. I think you're on the right track, but I guess the thing is to just do a cleaning infrequently, especially if there's a noticeable drop in mpg. Don't make it a yearly thing, for example.

 

I will venture my opinion. Simply cleaning the MAF following the directions on the CRC cleaner does NO HARM EVER! Based on my knowledge of chemistry and physics, it's simply BS that cleaning ever did ANY harm! If there was dirt holding it together it had already failed, you just didn't know it yet! IMO it should be cleaned EACH and EVERY time an air filter element is changed! That dirty air cleaner has let some CRUD through and it has likely stuck to the hot wire in the MAF sensor causing inaccurate readings which in turn result in a loss of the fine tuning Toyota has implemented. Again IMO cleaning the MAF sensor should be among the first things done whenever poor fuel economy is observed.

 

I'm not trying to "shoot down" your efforts. I think what you did is good. I just recall a thread: someone was doing MAF cleaning with the regularitity of oil changes, and it failed, needed replacement. There was some debate that frequent cleaning could have been a factor.

But hey, if you want to get out cap locks and the BS cannon, be my guest, lol.

 

Lately the weather has been warmer compare to December and January in California, so plai7778 you should be getting better fuel mileage than couple months ago. Keep us posted on your average and effort to improve gas mileage.

 

Warranty replacement?