What is MPG of hybrid without the battery?

[sl2eggplant]

Do you guys know what is mpg of a hybrid without the battery? For example ..
what is mpg of Prius (or Insight or other hybrid) with the battery pack removed, broken, or fully drained. I'm just curious how the hybrids compare on mpg without the battery to compare conventional all gas cars.

[RobertSmalls]

The Prius' battery is the only way to start the engine, so you can't really remove it, but perhaps that's irrelevant to your question.

The funny thing is, hybrids get better mileage when you don't use electric assist and regen. Driving without brakes outperforms regenerative braking every time. Electric assist needs to be paid back with interest, so I avoid that too.

However, having regen available makes a hybrid much more forgiving to drive by recapturing a good percentage of your kinetic energy when you need to brake gently. Similarly, you might be forced to do an occasional jackrabbit start, but with electric assist, you don't need to exceed 3000RPM.

A stick shifted hybrid makes engine re-starts very easy, so if I'm going to be in N for more than three seconds, I hit the kill switch. Then just tap the throttle pedal or shift into gear to restart the engine.

Because they knew assist would be available, Honda were able to put a 1.0L in the Insight and a 1.3L in the Civic. That will save you bigtime when cruising.

So anyway, to answer the titular question, a little better than stock when driven carefully, and much less around town when driven like a typical american would.

[jamesqf]

It'll also depend on your driving conditions. If you drove mostly on flat highways, and didn't care how long it takes you to get to cruising speed, you'd probably get slightly better mpg without the battery. On the other hand, if you drive a lot of hills, the battery allows you to recoup energy that'd othewise be wasted, so improving mpg. With the Insight, for instance, I can do maybe 1000 vertical ft of mountain at 50 mpg rather than 30, and if the mountain roads I typically drive were only that high, rather than 2500-4000 ft, I'd do a lot better on mpg.

[itsnotme1988]

It would basically be like a Metro with better technology, no? Tiny engine, light weight (hybrid - batteries.)

[C3H8]

on the highway under steady speed the heavy hybrid battery shouldn't add anything positive to the car, in fact i bet it reduces mileage because of 2 things.
1. is increased weight
2. is increased electrical load as the car tops off the battery and continuously trickle charges it to maintain it.

if i wasnt 6'5 i would LOVE to own a battery less insight. i bet i could smash the epa mileage rating with proper eco driving in the city and the extensive drafting behind semi's i do on the highway.

last thing i want to say, someone else said you can't start a prius without the hybrid battery. my uncle has a first gen prius and he recently replaced the STOCK Toyota 12v battery that is used for starting the car. toyota wanted over $100 for it, he put a $20 lawnmower battery in it and its been working fine for over a year. i believe the first gen prius starts off the 12v battery, but i am not certain. i know for sure that you don't need the expensive toyota battery though.

f

[Patrick]

The Prius traction battery only weighs 149 pounds. It is 201.6V, so you would need 17 lawnmower batteries to equal it. I'm not sure that would be lighter or less bulky.

[C3H8]

for some reason i thought the prius battery was 70 volts. maybe i am thinking of some other car. i guess nevermins the whole serial thing.

[RobertSmalls]

@propane:

The self-discharge rate of a 70% charged Insight battery is around 0.2 Watts. I'll bet your 12V lead-acid battery self-discharges much faster than that despite its much smaller capacity.

The Insight's 60lb battery increases rolling resistance to the tune of ~57W (versus the car's 7KW road load at 60mph). It has to capture only one regenerative braking opportunity per hour to pull its own weight.

Lots of people talk about wanting to strip the hybridness out of an Insight or a Prius, and maybe I used to think about it too. But now that I've driven one, I'm completely sold on hybrids. I'll never buy another car without a traction motor.

[ac7ss]

Originally Posted by C3H8

...
if i wasnt 6'5 i would LOVE to own a battery less insight. i bet i could smash the epa mileage rating with proper eco driving in the city and the extensive drafting behind semi's i do on the highway.
...

I am 6'3" and have a couple of inches of head room. have you sat in an Insight 1g?

[Daox]

Originally Posted by C3H8

last thing i want to say, someone else said you can't start a prius without the hybrid battery. my uncle has a first gen prius and he recently replaced the STOCK Toyota 12v battery that is used for starting the car. toyota wanted over $100 for it, he put a $20 lawnmower battery in it and its been working fine for over a year. i believe the first gen prius starts off the 12v battery, but i am not certain. i know for sure that you don't need the expensive toyota battery though.

This is somewhat correct. The electronics boot up on 12V and do some diagnostics, then the high voltage pack is used to fire up the engine. So, really you can't start with either of the two dead/missing.