Prius Eco 58 MPG vs Prius 54 MPG - What's the difference?

Yes, but your battery has a huge capacity, by comparison. From what I've read, you can draw a lot more amps out of a NiMH battery in a short period of time. That should mean more power for the electric motor when you need full power. I'd like to see some 0-60 mph acceleration tests of the base 2 vs. the 3. The NiMH battery should be able to store more regen energy too.

The gen 3 has more HP. Can it go 0-60 faster than a gen 4?

 

i believe it's discussed in other threads, but if you've moved on from interior space to acceleration, you might just want to stick with nimh. of course, the best thing is always a test drive.

 

Hopefully Toyota is not going down the same rabbit hole as Honda: overtaxing batteries. Toyota's track record on this is good though.

(I must have rabbits on the brain, lol.)

 

The last thing I care about is 0-60, especially the way I drive.

 

same here. but it is a consideration for some people. i think that's part of tesla's lure. it's the reason honda tried a hybrid accord originally, but that didn't pan out too well.

 

Everything that I have read says the opposite. Li-Ion has a much higher charge and discharge rate than NiMH. If you look at the chart that Tideland Prius posted earlier, it shows Li-Ion with 28% better charging performance. As for the the capacity difference, I read somewhere that the Li-ion pack is able to use 80% of it's capacity where the NiMH pack only uses 40%. So 6.5Ah * 40% = 2.6Ah for the NiMH. 3.6Ah * 80% = 2.88 Ah for the Li-ion. So they actually have similar useable capacity with Li-Ion having 28% better charging performance.

 

For what it's worth, the claimed fuel economy figures for the standard 2016 Prius are using a NiMH battery, meaning they're on the Two, per the 2016 Fuel Economy Datafile (can't link it yet, I don't have enough posts).

Toyota is required by law (40 CFR 86.1832-01) to include options that more than 33% of the model line has installed if they don't break things out into a separate model (as they did with the Eco). And, if one of my local dealers is representative, the vast majority of production is Twos. If more than 33% are Tourings, AND more than 33% are Twos, then you get a custom model made just for the test - a Two with 17" wheels and some other things.

I could believe that most of the impact is from the battery, though - Li-Ion tends to have lower internal resistance, which doesn't just mean that you can put more power into the battery safely, and get more power back out safely, it means that you turn less of that power into heat, and get more of it to the wheels.

 

It's the opposite. NiMH has a lower internal resistance. That's why I said what I did a few posts up.

 

Are these tires still standard on the Eco? Because the reported dismal wear rate, handling and wet/snow traction in the TireRack.com reviews would make buying this model a non-starter for me. Replacing tires that soon obviates the Two Eco's MPG savings, as well as giving inferior road performance. At some point, it appears chasing ever more MPGs becomes a losing proposition when detriments outweigh the benefits.

 

There was a tire survey thread a while back. Tires for the Eco do not seem to be unique. I believe some people had Ensaves on non-Eco and some had Ecopias on the Eco.

My Twi has Japanese Ecopias. I think they are lower rated than those made elsewhere.

 

The real reason the ECO gets better mileage is in the factory recommended tire pressure. See p. 730 of the 2017 Prius Owner's Manual, and you'll observe that for the ECO model ONLY, they set the tire pressure at 39 front, 36 rear, whereas for the non-ECO models (same tire type), they recommend 36/35. Those of us dyed-in-the-wool Prius owners know that even in the Gen 2 models, you can improve mileage by 4 mpg by upping the tire pressure to 40/39. Sure, the ride is harsher, but the MPGs are there! Giving up 65 lbs of empty weight is NOT where the ECO mileage comes from....

 

To be fair, giving up the 70 (not 65, IIRC) lbs of empty weight meant that it had a test weight of 3310 lbs, which is rounded down to 3250 lbs of test equivalent weight. (Also, the dyno has 3000 lbs of inertia at 3250 lbs of test equivalent weight, the rest of the load has to be simulated.)

The 3380 lbs test equivalent weight of the other cars is rounded down to 3375 lbs of test equivalent weight, which is rounded up to 3500 lbs of inertia loading on the dyno. (The dyno has to simulate LESS weight in reality.)

And that's how a 70 pound weight difference in the real world becomes a 125-500 pound weight difference on the dyno (and it can be as much as 250 pounds if they don't have the weight capability in their dyno). And, had the Eco been 3 pounds heavier, it would've gotten that 125-500 pounds on the dyno, too. There's where the Eco's mileage comes from.

 

i'm glad we've finally figured it out after 233 posts.

 

I've owned gen3 Ni-MH and Li-ion (plug-in), definitely pip was the winner in any way of battery usage.
When ICE is running it charges faster than Ni-MH. Feels I have more EV range before ICE kicks in.

My gen4 eco has Li-ion and I definitely feel its much better than my pip's.
Stays more EV and uses ICE less.
I would love to drive gen4 with Ni-MH for comparison.

 

what does that mean

 

It means that with low thread deep those tyres still grip very well, but because of low thread deep I had to throw them.

 

oh yeah that is good grip. how did you measure that and what is a healthy range?

 

Did anyone try driving a stock prius 2 without the spare tire and the same tire pressure vs a stock 2 eco?

 

I doubt removing the spare and raising tire pressures would make a lot of difference. A little for sure, but maybe there's some tweaking of the programming, or who knows what.

There was something, that lowering the weight put it in a different testing regimen? That the "improvement" was due to this?

Still, I believe it was Wayne Gerdes at CleanMPG that said there was a definite increase in mpg for the ECO, having driven both under similar conditions.