Trying to figure out what my MPG should be

B mode is only for engine braking on long downhill grades, not for anything else. My guess is that your use of B mode explains your low mileage. Hope this helps

 

In Kansas you likely would never need to use B - use it the same as you would use low on a regular automatic. The other piece of advice would be to stop thinking about mileage so much - just drive it normally, same as if you had a Civic and wanted to maximize mileage.

 

Looking at a topo map, I see a total elevation change of less than 300 feet, and only shallow hill slopes. You have no reason to use B mode. It hurts mpg in city traffic, and does nothing on the highway (unless your driving style including pulsing the gas pedal, in which case it will hurt on the highway too).

While the 75 mph section hurts, it should still allow mid-40s mpgs. But the wind, if it blows all the time, is costly.

Setting the climate control to 75 for the first 5 minutes, when the outside temperate is in the 20s, definitely hurts while the car is warming up. If you can reduce or delay that setting until reaching the 65 mph road, it should help a bit. But you may just have to write this off as a cost of keeping the wife happy.

How many tanks of fuel have you used in this new car?

While getting accustomed to this new car, make a habit of resetting one of the trip meters when starting the car each morning, or even each direction of your commute, so you can get faster mpg feedback. This helps to refine your driving habits faster. The MPG reading will start out pitifully low, even single digits, as the car warms up, but this doesn't matter. The number will increase throughout the commute (except maybe during the 75 mph section), and should reach its maximum at your destination. This is the number that matters. And you may find that wind causes one direction of the commute to read much different than the other.

And don't cheat by waiting a minute or two after starting to reset the trip meter. Well, you can, and it will read much better this way, but the results will never be comparable to the readings from truly cold starts.

 

i don't think breaking it in will help much. stay out of b mode for a tank and see where it goes. if that doesn't get you into the 40's, you'll probably have to slow down on the highway. most people get high 40's low 50's in normal driving.

 

On the Gen III Prii, you should be blocking the lower grill, NOT the upper. this is different than the Gen II.

 

Check out this software simulator form Wayne Brown. He is one of the seminal Prius hackers of all time, and all-around genius to boot.

To answer your question -- yes, most of your low MPG is explained by the cold, your driving speeds, and the wind. B mode use has not been helping.

 

I would not bother with the EV mode use. It only works when the car has warmed up.
The grill blocking is a good idea - I would only block half the lower grill unless a bought a scangage to monitor the temp.

As the tires break-in (500 miles or more) you should get around 40-42 MPG winter and 50-52 MPG Summer.

 

which battery is running the accessory mode? Could that be hurting his mpgs as well?

 

That shouldn't make any difference. Whether it is the 12 volt or main battery it still has to be charged up from somewhere, which, barring a solar panel or two, means from the main propulsion battery or the engine running or regenerative braking. Any of those cost energy, which eventually "hurt" mpg.

I bet the use of "B" mode is the main culprit.

I bet most people never use "B" mode at all.

 

Thank you for your service in the U.S. Coast Guard. (What coast are they guarding in Topeka, Ks. ? )
I don't see any mention of your using "B" mode in your original post, yet several following posts blame that for your mileage.
My daughter bought a 2011 with level 2 trim, and reports getting around 48 mpg in and around Cinncinatti and Northern Kentucky, with a similar commute time to yours. She now has about 5K miles on it, but has so far had mild winter weather and temps. She found that leaving the selector in "normal" gets her the best mileage.
One suggestion would be to back off on the loud pedal a bit on that toll road. You can watch the instant mpg readout to see what that added ten miles per hour is costing you in fuel consumption. Good luck.

 

Compare the timestamps on those posts to his most recent edit timestamp.

 

Ah, now I see where he probably changed it. The question now is whether it was a typo originally, or has he actually been running in "B" mode all the time?

 

I have found an incredible drop off for every mph over 50 or 55. When I drove to the Georgia line from Miami on turnpike and interstates I never broke 40mpg until I got to where I was going because I was in a hurry, but when I drove from Miami to Key West, on US1 which has varying speed limits but basically tops out at 55, I was over 50mpg. HUGE difference. Especially if you are trying to keep up with traffic to avoid bullet holes in the side of the car as we have to in South Florida.

 

Car and Driver: Mileage? No, it's Your Gallonage that Really Counts | PriusChat

 

For cold weather, turn off the heat/fan until the engine temp hits 150F (if you have not instrumented for that with a scangage just wait for 3 minutes of driving ) then it is ok to use the heat. Block only the bottom grill openings , not the top , unless you instrument the Inverter temperature. Use slight rises in the road to pulse and glide a bit . Keep your built in instrumentation on HSI and learn what the different sections of the display show you. Tires should be at 44 psi. Once you get the hang of how this car drives, you can easily get winter mpg's in the 50's, summer in the 60's even running snow tires. These are great cars capable of much better than the EPA specs, but it takes a while to get the hang of maximizing your MPG. That stretch of 75 mph will drop you maybe 3-4 mpg on your commute. If you get into how it works, adding a Scangage helps you to keep the engine HP at about 20 when you need the engine, and lets you coast using elec to propel you when the engine is not needed for drive. After a while it just becomes second sense and your yearly mpg will go way up..

 

^^^
Yep, I've included some of the HVAC management tips at http://priuschat.com/forums/gen-iii...mileage-gets-worse-in-winter.html#post1411488. I almost never use auto since I don't know what it's going to do (e.g. cause the ICE to run to provide cabin heat) or if I'm careless, it might run the AC compressor when I don't want it to run.