2023 XLE AWD only getting about 40MPG -- Wth?

welcome!
hybrids mpg's fall with colder weather due to physics and hvac use. also, tyres pressures drop and should be checked regularly as temps keep dropping.
without knowing your driving habits, it's hard to make recommendations. are you measuring your mpgs at the pump?

 

You're either gassin' it off the line, driving 75+ on your commute, or taking a bunch of short trips.

For me to get 40 MPG's, I've gotta idle with heat + defrost for 1.5 hrs, then drive an hour on snow covered roads in freezing temps.

 

Try inflating your tires to about 43/42 psi. Cold temperatures, even more so below-freezing temperatures, will especially lower your tire pressure.

 

The changes to the Gen 4 and even more changes to the Gen 5 make both a completely new efficiency game from the older Gen Prii. Some of the older Prii efficiency tricks still work with the newer versions, but the tricks have to be adjusted to the new powertrains. Other old tricks don't work at all and some of them even decrease the newer cars efficiency.

 

Shorts trips are a killer! If she can combine a few, and even visit the furthest trip first, you'll see a penalty reduction in MPG's.

 

I think the gasoline formulation changes for winter, too (this from a gas station owner). Every car I've had (including the gen 1 and gen 3 Prii and our '23 HyCam have poorer mileage starting in about September regardless of the weather (I'm in Kansas, US). I drive the same, and the mileage drops. On my '23 Limited, I am getting around 46 on short (20 miles or less) trips with slightly higher on the Interstate - once as much as 51 over 100 mile turnpike trip. Of course I don't even have 2000 miles on her yet, so I'm withholding judgment for another season or two.

 

In short, yes they can. One extreme example is route 14 north out of Watkins Glen, where the speed limit changes from 35 in town to 55 while going up that long foot hill and most drivers wanting to go at least 65... If not pushed by traffic on the ups and downs you can do alright by doing a modified pulse up and glide down but all mpg bets are off with traffic behind pushing more speed up and down.

And the Prius computers keep track of previous drives, so sometimes seeing a difference in mpg takes a while to show up as the computers adjust the present trips mpg and calculate it with the history data already saved.

 

Hurt MPG? Yes. Negate hybrid benefit? No, it hurts them all.

My feeling, not universally shared, is that on the mountain round trips, MPGs are lost mostly on the downhills. The uphill side doesn't matter much, climbing simply requires more fuel no matter how it is done. If the engine is kept operating at or near its highest efficiency, it all works out about the same.

When the downslope sides are shallow enough to not require friction or engine braking, the uphill fuel penalty can be recovered so that the roundtrip MPG penalty can be minimal, if handled well. Some driving styles unnecessarily squander a good deal of this recoverable gravitational energy. On steeper slope, the safety requirement for friction- or engine-braking necessarily wastes much of it for everyone, reducing MPG.

I can confirm this from my refinery-industry relatives, though it is also well known from other sources and discussed in various threads here. Including from some links in here:
https://priuschat.com/threads/why-mileage-gets-worse-in-winter.99492/

The short version of seasonal fuel differences is that summer fuel requirements, for lower vapor pressure to reduce evaporative emissions and prevent vapor lock, make gasoline more dense, increasing the energy content per-gallon (though not necessarily per-pound). Winter fuel requires a higher vapor pressure for easier cold starting, which reduces density and thus MPG.

Winter does numerous other things that also reduce MPG.

 

Short trips are indeed a killer. I do mostly longer trips on the weekends, and I get about 48-49 a gallon. I do a lot of very short trips during the week (I drive to different campuses multiple times a day for work), and really see the MPG suffer and trend closer to 40.

 

Interesting. I didn't know that, but I've sensed it with this new car on our regular run to town. I don't have enough miles on her for adequate evidence YET. Thanks for the info.

 

Still, I'm surprised that getting the car in June and mentioning your mileage started dropping in 70 and 80 F weather. Do you start early in the morning? This summer was extremely cool for us on the shores of Lake Ontario and night time temps were even less seasonal here all summer. I did notice it was much harder this summer recovering from last winters lows.

 

Hey there, I live in NYC and when I first got the vehicle I was getting around 51-55 mpg. Since it was break in period, I was driving like a grandma, I would never even go past the first half of "eco" on my speedometer. But i do think winter has some sort of impact on my mpg, If I drive conservatively I think I can definitely get 44 45 MPG out of it, but as of right now, I average around 40-43 since I drive quite fast. Cheers!

 

Chiming in as a mpg-watching former owner of the smallest Prius and currently of the largest one

Your initial 48 mpg doesn't look particularly disappointing, because your Prius has 19" wheels, which imposes a 10% penalty on the fuel consumption (says Toyota). Also, the AWD-e may be responsible for a few %% as well.

Incidentally, we traveled to Watkins Glen in the end of Sep 2023, and I remember it was fairly warm (65-ish maybe), so probably the temperature was not a factor. I cannot say if they already switched to the winter gasoline blend, because we completed the whole round trip on our "cheap & good" Virginia gasoline.

The wife factor could be at play as well. In our family the mpg difference is 20%, because she has been a Mazda girl for 25 years and does not humor any of the Prius gas saving rituals, such is coasting to a stop or "sensible" acceleration.

 

The 19 inch wheels are an MPG hit but Toyota's AWDe system only has a minor affect on MPG (It adds a bit of weight. My 2020 AWDe with 15 inch wheels is averaging 52 MPG to date.

JeffD

 

I think it's the friction in the rear axle gearbox and motor that affects the efficiency rather than weight, especially in the case of your Prius where the rear motor is relatively small.

 

Heard winter blend is 3% less energy than summer.

The gen5 AWD is a different beast than the previous one. That was a small motor of about 10hp that only helped on starts and really low speeds. The new one is 30hp that could be used at any speeds. So it can be used more often, and draw more energy when in use. then it has a larger braking effect when not energized.

Penalty actually doesn't end up much different on the EPA tests, but the OP is in the mountains where the AWD could get used more.