How much does Hybrid really contribute to mileage?

[kgall]

Hey, back of the envelope calculators! I've been wondering--

What mileage would the Prius get without the hybridization?

The rules of this question allow you to take off the weight of the battery and related parts, and substitute an available Toyota transmission for the ECVT, but you can't otherwise improve the car.

I'm wondering whether the battery power adds a whole lot to mileage?
Or is the Prius basically a really efficient ICE car, which needs the battery because otherwise it doesn't have enough power for most folks' accelleration habits?

[a64pilot]

Originally Posted by kgall

Or is the Prius basically a really efficient ICE car, which needs the battery because otherwise it doesn't have enough power for most folks' accelleration habits?

That is what I think, but it would probably be a real dog, but I think it would get even better highway mileage and you would have to leave the ECVT. Probably be really bad in the hills / mountains, and city mileage would suffer.

[spiderman]

This should be straight forward... take the
Corolla 1.8l w/automatic:
132 hp @ 6000 rpm; 128 lb.-ft. @ 4400 rpm, combined FE: 30
Prius
134 hp @ 5200 rpm, 105 lb.-ft. @ 4000 rpm, combined FE: 50

So if you overlook the differences in transmissions it is obvious to me the hybrid system contributes a great deal. I think the big advantage is is the engine is off when it is not needed.

Perhaps I am over simplifying the question.? I do that a lot.

[DeadPhish]

There's a real simple comparison. Compare the Prius to the non-hybrid Prius, it's easy.

There's a non-hybrid Prius ? Yep there has been all along, right there hiding in plain sight.

The Prius is a smallish, 5 door hatchback with a 1.8L ICE tuned to the Atkinson cycle, plus two e-motors ( MG1 and MG2 ), a battery pack and an ECVT in place of a traditional transmission.

What Toyota vehicle is also a smallish, 5 door hatchback with a 1.8L ICE tuned to the Otto cycle...without the hybrid equipment..but including a traditional transmission? It's the Matrix, the non-hybrid Prius.

Matrix combined EPA number is 28 mpg, 25 City / 31 Highway
Prius combined EPA number is 50 mpg, 51 City / 48 Highway

The rest is easy. BTW these increases in fuel economy are pretty consistent with all four of the major hybrid systems; HSD, IMA, Ford and the GM 2-Mode. Essentially what the hybrid systems do is to improve the fuel usage of the basic ICE-only systems by about 40% on average.

Matrix uses 35.7 gal to drive 1000 miles.
Prius uses 20.0 gal to drive 1000 miles, a 44% improvement.

[DeadPhish]

Originally Posted by spiderman

This should be straight forward... take the
Corolla 1.8l w/automatic:
132 hp @ 6000 rpm; 128 lb.-ft. @ 4400 rpm, combined FE: 30
Prius
134 hp @ 5200 rpm, 105 lb.-ft. @ 4000 rpm, combined FE: 50

So if you overlook the differences in transmissions it is obvious to me the hybrid system contributes a great deal. I think the big advantage is is the engine is off when it is not needed.

Perhaps I am over simplifying the question.? I do that a lot.

Matrix 1.8L AT...

[spiderman]

Originally Posted by DeadPhish

Matrix 1.8L AT...

Silly me... why didn't I think of the Matrix?

[jburns]

Originally Posted by DeadPhish

There's a real simple comparison. Compare the Prius to the non-hybrid Prius, it's easy.

There's a non-hybrid Prius ? Yep there has been all along, right there hiding in plain sight.

The Prius is a smallish, 5 door hatchback with a 1.8L ICE tuned to the Atkinson cycle, plus two e-motors ( MG1 and MG2 ), a battery pack and an ECVT in place of a traditional transmission.

What Toyota vehicle is also a smallish, 5 door hatchback with a 1.8L ICE tuned to the Otto cycle...without the hybrid equipment..but including a traditional transmission? It's the Matrix, the non-hybrid Prius.

Matrix combined EPA number is 28 mpg, 25 City / 31 Highway
Prius combined EPA number is 50 mpg, 51 City / 48 Highway

The rest is easy. BTW these increases in fuel economy are pretty consistent with all four of the major hybrid systems; HSD, IMA, Ford and the GM 2-Mode. Essentially what the hybrid systems do is to improve the fuel usage of the basic ICE-only systems by about 40% on average.

Matrix uses 35.7 gal to drive 1000 miles.
Prius uses 20.0 gal to drive 1000 miles, a 44% improvement.

If only it were that simple. All sorts of other things enter into this. Aerodynamics for one, especially on the Prius.

[rachaelseven]

Originally Posted by jburns

If only it were that simple. All sorts of other things enter into this. Aerodynamics for one, especially on the Prius.

Correct. And I believe the hypothetical posed by the OP presumes that the Prius would keep its Atkinson cycle, shutting off at stops, etc. Imho, the only way the battery/hybrid aspect actually improves mileage is in recovering kinetic energy during regenerative braking. Beyond that, the Prius is in fact just a really efficient ICE vehicle, as far as I can see. So in my mind, the question boils down to how much energy would be lost due to friction braking in the absence of the battery and regeneration capability? Ladies and Gentlemen... start your napkins!

[jburns]

Originally Posted by rachaelseven

Correct. And I believe the hypothetical posed by the OP presumes that the Prius would keep its Atkinson cycle, shutting off at stops, etc. Imho, the only way the battery/hybrid aspect actually improves mileage is in recovering kinetic energy during regenerative braking. Beyond that, the Prius is in fact just a really efficient ICE vehicle, as far as I can see. So in my mind, the question boils down to how much energy would be lost due to friction braking in the absence of the battery and regeneration capability? Ladies and Gentlemen... start your napkins!

Base Matrix is 7% lighter than the base Prius as well. Gets complicated in a hurry.

[JimboPalmer]

There is a non-hybrid Civic and a hybrid Civic, find the FE ratio and apply it to the Prius.
City 26 Hwy 34 Comb 29 vs. City 40 Hwy 45 Comb 42 = 69% as good, so I would expect 34.5 combined for a non hybrid Prius (Postus?)

(You could use the Camry, hybrid vs non-hybrid, but the Civic is a closer weight match)