Question about low speed EV mode on hybrids - Fuel Economy, Hypermiling, EcoModding News and Forum

Cd · 11-20-2011, 11:11 AM

From what I understand, the Honda Insight doesn't have a pure electric mode like the Prius when driven around 25 mph. Is this correct ?

Also something I wonder about with the Prius is just how far that you can drive on pure EV mode.
If I am stuck in 30 miles of bumper to bumper traffic, how many miles of that would be pure EV if the speed never reached over 20 - 25 mph ?

jamesqf · 11-20-2011, 11:27 AM

True about the Insight.

mort · 11-20-2011, 03:49 PM

Quote:

Originally Posted by Cd

Also something I wonder about with the Prius is just how far that you can drive on pure EV mode.
If I am stuck in 30 miles of bumper to bumper traffic, how many miles of that would be pure EV if the speed never reached over 20 - 25 mph ?

Hi Cd,
The Prius has approximately 2 hp-hr battery capacity. If you start your crawl with the battery "full" and discharge down til the engine starts to recharge it you can use about 1.2 hp-hr. The Prius uses about 2 or 3 hp to maintain 25 mph. So the most optimistic estimate is at a constant speed you could go about 15 miles. But if it's stop & go, the accelerations and braking will reduce that considerably. Accessories too. High or low temperatures reduce battery capacity.

-mort

Daox · 11-20-2011, 10:17 PM

In ev mode you're lucky to go 1 mile. Unfortunately, 15 miles it totally unrealistic.

niky · 11-20-2011, 10:41 PM

EV Mode, just over a mile... 2 kilometers tops (from a dead stop), and at a limited top speed. After that, you have to recharge. We tested it during an eco-run.

It's possible with the battery size of the Prius, you could go further, but the system limits it to preserve battery life.

Cd · 11-20-2011, 11:32 PM

Well this certainly changes my views on the Prius versus a traditional high mileage car.

So after a mile of stop and go traffic, a Prius fires up its engine and pollutes like the rest of us ?

Hmmm. No thanks.

mort · 11-21-2011, 06:48 AM

Quote:

Originally Posted by Daox

In ev mode you're lucky to go 1 mile. Unfortunately, 15 miles it totally unrealistic.

Hi Daox,
I have a Ford Fusion Hybrid. My morning commute includes a stretch of about 4 miles, flat, no lights or signals. 40 MPH speed limit. Most mornings I get to beginning of this stretch with the battery at about 50%. I get up to 40 using the ICE and hit cruise. I make it to the next signal in EV with some battery to spare. So my FFH easily does 4 miles in EV starting with 50% soc.

-mort

niky · 11-21-2011, 07:28 AM

The Prius merely exits EV mode and goes back to hybrid mode, meaning it pollutes under hard acceleration and doesn't pollute under gentle acceleration, when coasting, when stopped at a stoplight and when decelerating. Like I said, it seems the short range on EV mode is more to protect the battery than because that's all the charge there is.

If we count cruising while already at speed, the Prius can easily do a number of miles without using gasoline when the battery is topped off. The 2 kilometer limit we tested from a dead stop.

Daox · 11-21-2011, 09:51 AM

I use EV mode every day my Prius since I have a plugin kit. I've also used it without the plugin kit and I'm saying in normal driving you're lucky to get 1 mile. If I was already up to speed and just coasting along, yeah you can get more. I'm also not sure, but I'd guess the Fusion's pack is larger than the Prius' pack just because its a larger vehicle.

If you're looking at pollution, you aren't going to get much better than a Prius unless you go to an EV.

mort · 11-21-2011, 06:05 PM

Quote:

Originally Posted by Daox

I use EV mode every day my Prius since I have a plugin kit. I've also used it without the plugin kit and I'm saying in normal driving you're lucky to get 1 mile. If I was already up to speed and just coasting along, yeah you can get more. I'm also not sure, but I'd guess the Fusion's pack is larger than the Prius' pack just because its a larger vehicle.

If you're looking at pollution, you aren't going to get much better than a Prius unless you go to an EV.

Hi Daox,
Wow, I thought this guy was doing about average, 5 miles in traffic.

Anyway, I noticed the OP's reply. It wouldn't matter if you could go EV mode for a hundred miles in a hybrid (non plugin). All the electrical energy comes from burning gasoline. And I agree, the Prius is about the lowest emission auto you can buy.

-mort