Fuel economy for short distances

Short trips will be less efficient. If you can, incorporate a grocery run or whatever chores, together with a drive, that'll help some.

One thing we did was get the block heater (eight o'clock, day one), and use it year 'round, ideally for 2 hours before each cold start. The part's about $90; installed they'll likely ding you over $400. Not sure if it's any easier than gen 3 install, which is a bear. Likely the same; the engine's very similar.

 

Numbers read about right for that model in that climate.

Good work!

 

For a Prius HEV, that might be close to normal. The secret to good mileage is to stop the engine when it's not needed and run off the battery whenever possible. The short drive with a cold engine and cold cat converter will result in the Toyota HEV running in almost the same way as a conventional ICE model. The engine will run even when stopped at a traffic light if the cat is not yet up to operating temperature.

I saw the same thing with my GEN 1 Prius back in 2002. I lived in an area where the first half mile drive on my daily commute was multiple stop signs and then a school zone followed by 2 miles of stop and go traffic signals. A cold winter morning almost always showed low mileage, often in the 30 MPG range for the first 5 minutes. Once I reached the freeway the MPG became much better. By the time I was at work (30 miles away) the MPG had jumped up to high 40s or low 50s.

One of the things that I really like about my Prius Prime is that the first part of every drive will be run in a non-polluting mode and then switch over (if needed) to gas on the long high speed sections where it is more efficient.

 

A very crude rule of thumb I made with my first Subaru was that a cold start cost about 2 miles of fuel for engine warmup, in addition to the fuel used to actually move the car. I.e. if driving 3 miles from a cold start, it would consume ~5 miles worth of fuel. Try some similar math to see if it (sort of) fits your observations.

My Gen3 Prius seemed somewhat similar, though for really short drives, it wasn't quite that bad because it wouldn't get fully warmed up before the end of the trip. E.g. for a half mile trip, it didn't really use quite 2.5 miles of fuel because it didn't get fully warmed.

This is why EVs and PHEVs really shine for short trips, at least absent any need for cabin warming or cooling. I'm now really enjoying running errands around town or attending nearby events in a RAV4 PHEV, with the ICE remaining stone cold. And quiet. Though now the rooftop solar system needs another expansion ...

 

Why? The Prime has a heat pump and unless the temperature gets below -10°C or you use the defroster, the engine will stay off.

 

you need a prime my friend

 

Is that true of all EVs and PHEVs? I was being more generic than just Toyota Primes (Prius and RAV4).

On last month's ski trip, I did run into one morning where the ICE automatically fired up immediately on startup (at +3F), nevermind being in EV mode, and at least four more mornings where manual scrapping and heat pump just weren't going to get the heavy overnight ice accumulation cleared in reasonable time, so I fired up the ICE.

With the battery range reduction from cabin heat, plus all the electric resistance heaters (rear window, seats, steering wheel, rear view mirrors, windshield wipers), and extra resistance from snow and slush on the road, I probably wouldn't have made it to the ski hill parking lot solely on battery anyway.

 

Plus the heat pump’s getting its electrons from somewhere, will reduce electric-only range.

 

just more efficient than our bolt heater which boils the water and runs it through the heater coil

 

If they don't have a heat pump, they'll have a resistive heater, which is less efficient and will drop the range more than a heat pump.

 

As previously stated, I was trying to be generic to EVs and PHEVS, not specific to Toyota Primes.

 

seat and steering wheel heaters are very efficient

 

I just filled my tank tonight. I drove 478 miles in two days, in Metro Detroit with a 60.0 mpg. Temps were in the mid 50s - mid 60s F. (I drive Uber all day) Not my best by any stretch but good for these temps.
My experience is short trips + cold engine = crappy mileage

 

An update/addition: Today, with a freshly filled tank, cold engine and 46 F starting temp, it took me10 miles to get my mileage above 40 mpg. It took 45 minutes and 25 miles to get to 50 mpg. I finished my day with 248 miles and 59.4 mpg. The car was only turned off once, for 40 minutes while I got lunch. Temps finished at 63 F today. My driving (both days) included speeds from 25 mph in residential areas to 70 mph interstate travel.

Today works out to 3.96l/100km

 

This is all what the displays are telling you presumably? That’s excellent numbers, still worth keeping in mind; Toyota can’t seem to resist cooking the books; calculated will be 5~10% lower.

apparently with 5th Gen they’ve mended their ways though.

 

It seems you’re getting the hang of it. Temperature, speed, even the smallest electrical loads will affect the mileage. With the description of your conditions you seem to be doing well.

 

I've calculated the mileage several times over the years, it is spot-on with what the display reports. It was in FL & still is here in MI. And mind, I have 275,000 miles on this car.

Life of the car my mileage overall is 56-57. That's in FL summers with 95 F daily and now one MI winter that, while mild, saw temps as low as -4 F (once, mostly in the 20s). Worst mileage ever was 51 over a 3,000 mile road trip from FL to MI & back (mostly I-75) thru KY & TN mountains in winter. Mid 50s - mid 70s have been my sweet spot, have gone as high as 69 on a tank while running 35-50 mph roads in those temps.
(Actually, my worst mileage was when I moved up last Sept. I was towing a 550# motorcycle on a 300# trailer and had my back seat full of computers & TVs/monitors while the back was full of clothes. I drove no more than 65 mph up I-65 (less hilly) and squeaked out 42 mpg over 1300 miles. Ouch!)

I have spoken to several Toyota & other service people and they report the same thing. The key, as with any ICE or hybrid, is you need to get it up to operating temps before you'll get the good mileage. Avoid short trips (unless you string a bunch of them together in a big loop kind of thing, I suppose).

I think VancouverPrius needs a pure electric if that's all they drive. Or, at least, a plug-in hybrid. With the PH you'll need to take occasional long trips to keep the gas from going to sludge as my friend with a Jeep 4xe found out after over six months without using any gas.

 

I don't know about Jeep.

But Toyota, GM, and several other PHEV makers worked together with CARB (California Air Resources Board) to develop systems to keep PHEVs' fuel from going stale for a full year. How? Read here:

How designing the Chevy Volt's sealed gas tank brought automakers, CARB together | Autoblog

The Toyota Prime series -- my RAV4 Prime as well as Prius Primes -- say this in the Owner's Manual:

●For Plug-in Hybrid Electric Vehicles,
fuel may remain in the tank
for a long time and undergo
changes in quality depending
on the how the vehicle is used.
Refuel at least 5.3 gal. (20 L,
4.4 Imp.gal.) of fuel every 12
months (refuel a total of at least
5.3 gal. [20 L, 4.4 Imp.gal.] over
a 12-month period), as this may
affect components of the fuel
system or the gasoline engine.

I believe several Prime owners here, including a forum moderator, have gone over a year between refills without having (or at least mentioning) fuel problems.

My Prime is only a couple months old. The pattern so far is as I expected: most trips are all-electric, but most miles are gasoline, so it won't be getting anywhere close to a stale fuel problem.

 

Actually texted with my friend, the Jeep owner, last night. They have some software that requires that 4 gallons of gas be used every 3 months to "refresh the engine oil". Also, keeps the gas flowing thru.