Warm weather finally here, mileage suffering.

Okay, I bought my new/old '04 back in Jan, during one of the most remarkable winters we've had here in WV. I was quite pleased with the mileage driving about in temps down in the negatives and single digits and lots of snow.
I even used the prius to tow my little saw mill through the mountains of
PA in early Feb, and still got in the high 30s carrying a light trailer and
driving in snow. Very pleased, and man, was I ever looking forward to the warm weather when I knew that my high-40s to 50-ish was going to magically
jump into easy-to-maintain-50s and maybe even a 60-ish tank from time to time.

But alas! No joy!

I have a very difficult time even managing to hit a 50 average, it's almost like it was easier to hit a 50 average in the inclement weather.

So, here we go:


- Have you read This Thead Yet?

--YUP

- What fuel economy are you getting and how are you determining fuel economy? (trip computer or manual calculations)

Using the trip computer, getting in the low 40s to MAYBE 50.

- What fuel economy are you expecting and why?

in the 50s. Because I was getting this mileage during the cold heart of winter, without working very hard for it. When I drive the mrs's '08, I can keep it in the 50s without much effort, and in the 60s with some more careful attention.
During the winter, I was routinely getting better mileage than she was, and now she's waxing the floor with me.

- What are the approximate outside air temps?

40s to 80s.

- How long are your trips?

Daily ~50 or so.
Weekends involve multiple 140+ mile trips. Through the mountains.

- How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving?

I do very little city driving. Probably 85% is highway, in the city (what little driving I do, mileage is in the mid-30s).

- What region/state are you in? (if you haven't set your location in your profile)

WV, Va, Pa.

- What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.)

Yes.
(flat, gentle hills, steep hills)

- Is your oil overfilled? (i.e. above the full mark on the dipstick)

Nope.

How old is your 12v battery? What is the voltage reading of your 12v battery after sitting over night? (Method Here)

Errr, 11.2
EDIT
Actually, just checked it at 9.4v. Battery is probably original.

Have you had your alignment checked? Any pulling or abnormal tire wear?

Alignment adjusted after wheel bearing replacement last month,
was bad, now good.
No abnormal tire wear.


- Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g. Goodyear Assurance Fuel Max 185/65R15).

stock size,
very worn goodyears on the back, local tire shop snows in the front.

- What are your tire pressures?

35-front
33-rear
(checked often)

- Make, model, year, engine and transmission of previous car? (e.g. 08 Honda Civic Si 2.0L 4 cylinder, manual transmission) What did you actually get on the same trips/commute? (Please give us actual numbers, not EPA ratings.)

'98 subaru outback, actual 25 consistent, occasionally 27/28 (against a
gps, not odo, as the odo lies).

- How are you trying to drive (e.g. trying to stay in electric only?) and how hard are you braking?

Trying my best to stay as electric as I can, ice oftens comes on with any
pedal pressure at all, stays on, find myself running on the ice going
/downhill/ with >50% of battery available.

I brake gently. Very.

- Are you "warming up" the ICE (internal combustion engine) by letting it idle after powering on?

Errr, no, not really.

- Are you driving using D or B mode?

I've used B about 3 times in my life, descending long grades with the trailer
on, never used it with single passenger load. Though the car does act like
B is engaged on long descents.

- HVAC settings? Are you using the heater, AC, auto mode, etc.? If using auto, what temp is it set to?

Never used auto. I've used the A/C a few times lately when the temps went into the 80s. Normally, I run 'lo' at 70, fresh air.

- If reporting a mileage drop, did anything significant change on your car (e.g. accident, hit a curb or big pothole throwing off alignment, oil change/other maintenance/repairs, changed tires or wheels, etc.) or your commute?

No accidents/pothole slams, etc.

 

Yeah,

It's actually much worse than that. I went out and checked again (after
driving in to work this AM) the voltage I posted was from the first time
I checked it a while back,
Granted, the interior lights were on, but it came up as 9.4v, (14.2v running).
ICK!

New battery time.
have to wait a week to order the yellow-top kit.
Need new tires also.

Thanks for the hint.

 

Okay, I haven't yet replied, as I haven't been able to order the optima kit yet, next week hopefully, then I'll know more.

I'll post again after I replace the battery and run a tank through.

 

Okay, just a FWIW,

I replaced the battery with the optima kit. Nice kit by the way. Just need to sort out how to recycle the OEM battery now.

Ran a tank through it. No great improvement. Seems a *little* better. Not like her '08 though. I suppose that's fair, my '04 has 100K more miles on it. Still 'seems' like the ICE runs more often than it needs.

other annoyances have cleared up though.