Thinking of Prius from Corolla

Welcome aboard. Yeah, short trips is tough on the Prius... but perhaps a PiP might be more advantageous? Or even a full EV?

 

Yes it's true that the Prius gets poor mileage during warmup. It's really important to get the catalytic converter up to operating temperature.

But this is true of all cars these days. A more important question is the comparison between your Corolla and a Prius. I suspect that your Corolla is getting under 20 mpg during warmup, while the Prius is getting under 40 mpg during warmup. Once both cars are warmed up, there's no contest in short trip stop and go. The Prius shuts off the engine at stoplights, while non-hybrids continue to burn gas even when stopped.

The Prius does poorly against a BMW 3-series while racing at maximum power around a track. It may even do poorly against a Corolla in a similar situation. So choose the appropriate vehicle for your task. The Prius only does well in the real world. There are certainly better cars for racing.

 

Because of the short trips and also being in the cold NE, you will get lower mpg.

BUT I think the overall mpg will be higher than most if not all ICE cars.
If you are doing a apples to apples comparison with price factored in, it may
not look as good as longer trips.
If you plan to do any long trips, depending on length it may pay for itself
in one trip. If that trip is a long one

 

From my experience, conventional cars take less of a hit on extreme short trips than the Prius. I would guess that 90% of my mom's driving involves 2 mile trips and she averages 18-19 on her 2010 Nissan Altima 3.5L V6. The EPA rating for this car is 20/28. I really doubt that any Prius can average only 10% less than the EPA city rating under those conditions.

 

FWIW, on my former 04 350Z (older rev of the same engine), when I had a mostly short trips in a colder climate (in the Seattle area), I'd see 16-17 mpg, sometimes as bad as 13.x mpg.

FWIW, if one calculates "gallonage" (http://priuschat.com/forums/other-c...eage-no-its-your-gallonage-really-counts.html), even if one took a much bigger "hit" on the Prius than 10%, here are gallonage figures after going 100 miles:
51 mpg: 1.96 gallons used
40 mpg (much greater than 10% hit): 2.50 gallons used <-- delta 0.54 gallons

20 mpg: 5 gallons used
18 mpg: 5.56 gallons used <-- delta 0.56 gallons!

Best & worst cars review, fuel-efficient vehicles might give you an idea of short trip mileage. Last page of http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf describes their procedure and the old EPA tests.

 

EDIT -- I did more testing the next day:
At 60F, with the car sitting in a garage all night: I drove on neighborhood streets, with 3 or 4 stop signs. About two minutes into the drive, at the 0.3 mile mark, the engine shut off at the stop sign. So it was warmed up enough to allow the engine stop that soon.

On the freeway at the 2.3 mile mark, I reset the Trip A counter. After a mile at about 55 mph, it showed 55.2 mpg. So even that short of a drive had the engine in full efficiency mode.



My first test:
Even short trips can get good mileage. I wrote down my commute today. I just stayed with the flow of traffic, and didn't do any special driving techniques. The traffic was heavy enough to keep all the cars around 60 mph. Driving surface streets at 35-45 mph should get even better mileage. Going over 70 mph would decrease mileage.

Even a Corolla would need to warm up, by running at a faster rpm, and wouldn't warm up as fast as the Prius does.

Outside temperature 50F
The car was in the garage all night. I warmed up the car for 10-15 seconds, then shut it off for two minutes while I went back inside to get a few things I had forgotten to bring. So this probably warmed up the car just a bit earlier.

Distance / MPG / Average speed
0.5 miles / 15.3 mpg / (didn't note average speed)
The engine had already warmed up enough to shut off at the stop sign! In temperatures over 60F, I usually think it's warmed up enough to shut off at stops somewhere between 0.5 mile and 1 mile from the start. I haven't had it in the summer yet.
1.0 miles / 13.0 / 13 mph average speed. Maybe 3 or 4 stop signs so far. Now going 30-40 mph on the freeway feeder road.
1.5 miles / 28.0 / 17 mph. Starting 60 mph freeway travel.
2.0 miles / 29.0 / 20
2.5 miles / 33.0 / 22
3.0 miles / 35.1 / 24
4.0 miles / 39.9 / 28
5.0 miles / 42.0 / 31 already 42 mpg.
6.0 miles / 44.6 / 34
7.0 miles / 46.4 / 36
8.0 miles / 47.8 / 38
9.0 miles / 49.8 / 39
10.0 miles/ 50.0 / 40
12.0 miles/52.4 / 43
15.0 miles /54.1 mpg / 45 mph average speed. I drove mostly 55-62 mph from mile 1.5

(So how does it calculate average speed! 1.5 miles at 25 mph and 13.5 miles at 57 mph gives 53 mph average..It's including stopped time somehow. For instance, 1 mile at 30 mph = 2 minutes, and 1 more minute stopped would average 20 mph for the 3 minutes? I'll have to experiment someday.)

54.1 mpg is pretty typical. I would usually see 52-56 mpg for this route. In the winter, I was getting 46-48 mpg.

(Forum users say that the actual mileage is a few mpg lower than the display showed. So the 54.1 is more like 52 or so. But that's still 0.28 gallons for the 15 miles, or $1.15 at $4/gal gas prices!)