If Toyota could offer a 40 mile range Prius, I'd probably never need to run the gas motor

Any details on the battery pack used?

I have been reading this forum for almost every day for a few months and love this site. My 99 Subaru has 114k on it and I have been looking at new cars. I rented the 09 Prius for two days and really enjoyed driving it around town. I have to say it is not that great a highway driver as I could feel the rear end sway at high speed - I know that is not why you drive a Prius. Also the 09s are priced so well right now it just seem like a steal to get one now.
Then I saw all the photos of the 2010 Prius and am saying wait for the 2010. I am going to the car show this week to see one in DC and I will be sure to ask about the Li-ion battery manufacturer for the plug in hybrid and get any details they will offer. I sure hope my Subie makes it another two years!!!
Too many cars so little time....

The test Toyota Prius Plug-In is only a double NiMH battery. It is pathetic in terms of the electric range. It is not even remotely comparable to what a Hymotion lithium-ion 5 kwh battery provides.

I am not at all surprised that they only achieve 65 mpg.

I find my Prius really good on the highway. It will cruise 70 mph all day long, no drama. I've never felt the rear end sway. Then again, I've never done over 75 mph in it.

Prius' are everywhere in the Bay Area, highways, etc...

Like Car and Driver said 'the Prus is fully mainstream with sales of 180,000 units in year 2007'.

I enjoy driving my Prius on the highway, I take the car in preference to the bike.

If they're referring to the UK plug-in tests, which they've linked to, the 'driving cycle' (presumably EU New European Driving Cycle) is nothing like the one that the 2010 car claims 50mpg for - the current 2009 EPA driving cycle.

The NHW20 - standard, not plug-in - already gets 65.7mpg combined on the EU cycle.

Road tests cannot be compared with a lab driving cycle. A plug-in hybrid should return infinite mileage on the New European Driving Cycle - it only has to cover 11km (6.8 miles) in bursts, maximum speed 50km/h (31mph) in the 4km of 'urban' driving, maximum 120km/h (74.5mph) for about 10 seconds in the 7km of 'extra-urban' driving.

A lot of results that I've seen suggest that, since 2008's changes, the EPA results have now swung from too optimistic to too pessimistic.

I would much prefer "real" world results that are pessimistic, than pie-in-the-sky results that nobody seems to achieve

Without knowing what distances are being driven and what size the battery pack is, a claim of 65 mpg in "real world driving" is worthless. The plug-in aspect really changes the mileage a given car will get. I have a Hymotion pack in my Prius and I commute 28 miles into San Francisco (for a 56 mile R/T commute). Each way of the 28 mile commute almost completely depletes my plug-in battery (I can charge at work, so I get the battery boost both ways). I am mostly on the freeway with speeds up to 75 MPH (mostly between 55 and 65). The best I have ever done on this commute is 96 MPG. My average MPG is probably 83 or so. Of course, if my commute was say 33 miles, the battery would be deplted before I arrived and my MPG would drop into the 70s at least. On the other hand, I have had a few weekend days where I just had errands to run and only traveled maybe 8 miles for the day with sppeds of 45 or under and I got 160 - 170 MPG. So what is the MPG rating for my car? Hymotion claims over 100 MPG, which is possible, They also claim I should get 90 MPG on my commute, which I get close to (I was getting 45 - 48 on this commute with the stock Prius). In any case, my belabored point is MPG numbers for plug-ins are pretty meaningless without factoring in the distance the car is driven, how many hill climbs, etc.

Let's use 48 MPG as the real world fuel economy for the Iconic (04-09) model.

By doubling the energy in the battery pack, we are seeing 35% improvement (48 -> 65 MPG). Since lithium can double the energy of NiMH for the equivalent weight and size, this should be a preview of what to come....

Based on Google RechargeIT result (94 MPG at 5.5x), I created the MPG estimate based on the available / usable energy in the battery pack of the Iconic model.


Note: 1x = 1.31 kWh * 0.4. This is about 500Wh (10 green leaf cars) of usable energy from one NiMH pack (40% - 80% SOC). A123 L5 contains less than 3kWh usable energy. It looks like 6x would double the MPG of the non-hybrid model.

Lithium-ion plug-in Prius based on the Gen 3! If it were to get 35% boost in fuel economy, we will be looking at about 68 MPG (real world). That's assuming the lithium pack having double the usable energy. If it were to have 4x more energy, we should expect over 80 MPG (PNGV goal). I think 4x is the sweet spot because the battery pack should qualify for $2,500 of the "bail out" plug-in hybrid tax credit.

Interesting time ahead....

zcat3, have you ever tried a highway range test at 55-60 mph on cruise control? I did this and achieved a 41 mile range with my Hymotion.

Charge your battery to maximum, leave the house with the battery off. Get out on the highway at 55 mph (low traffic time period), set the cruise control, then turn on the battery and reset the odometer at the same time. Just determine your maximum range with no other variables of stop and go, fast speeds of 75 mph, etc.

When I drive to downtown San Diego from my house if I hold it at 65 and cruise control I finish with 58mpg when I exit the freeway. No Hymotion, no nothing, just stock with 42/40 in the tires and using cruise. If I do 55-60 during that same trip, it jumps to 62mpg granted I only did this once at midnight with no one else on the road.

Only time it would be safe to do so. Otherwise you risk a crash or a nasty road rager

Hey Peak - my commute involves some pretty large hills (like a 600 - 700 foot climb over 1 1/4 miles or so) and half of the freeway drive is a 65 MPH posted speed limit. I generally do stay in the 55 MPH range when climbing, but go faster when I can use downhill momentum. I also drive about 10 miles on a road where the speed limit is 50 or 55 but has 6 stop lights alonbg the way. Getting caught by the lights and then having to accelerate up to 55 - 60 really can hurt the over MPG. This morning I caught most of the light and got 90 MPG on the way in to work.

As for turning on the Hymotion pack while moving, Hymotion says this is a big no-no as it can reset some of the electronics in the car. You have not had any issues with this?

I could see that if I was on a flat road going 55 I could get maybe 35 miles range and 90 - 100 mpg, but my commute is nothing like that.

I wonder how much extra in terms of manufacturing cost is it to equip a Gen III Prius with a Lithium Battery pack that has 2X the capacity of the current 1.5Kw-Hr NiMH? Since both would use very similar support electronics and mechanical hardware - the cost delta is likely only the batteries themselves.

The only thing that happens is that it will disengage your cruise control if you are using it. There is no other side effect. It is safe to turn off your Hymotion battery while moving.