Popular Mechanics reviews Hymotion Prius

Real-World Long-Term data is what matters. Brief measure samples don't represent an on-going expectation. (They can be very exciting though.)

Google's RechargeIT mini-fleet is a good example. Their average is 69.2 MPG.

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I think one of the challenges is that PHEVs, and Prius conversions in particular are probably much more sensitive to driving style and trip length/speed/route than regular Priuses. Some of the folks on this board have illustrated that 100-180mpg is very achievable over a long period of time with some effort. The Google data is also all over the place depending on who is driving, how they drive, how far they drive, and whether they remember to plug the car back in and/or turn the pack on. A number of their datasets are offline at the moment, but one of their cars is averaging 61mpg, while another is averaging 98.2mpg even under these far from ideal circumstances.

Google.org
Google.org

Rob

 

I posted a couple of things as well in response to some of the comments, we'll see if they get posted. Sorry to post this twice, had put it in another thread but this seems like a better place for it

Rob

 

very interesting. This would for sure excite me to have this installed, but 10k?

 

It appears to me from reading the above quote in the PM article that they would see significant improvements just from including an EBH and grill blocking. This also appears to be a suggestion in a thread concerning the Hymotion with EBH. Do these modifications account for the higher mpgs that PC folks are seeing?

 

I still find it amazing that these people were only able to get 70 or so mpg. In warmer weather I've been able to hold 65-66 for several hundred miles of nonhighway driving and others in PC routinely do much better than that for an entire tank... I too would like to see this potentially great technology taken out of the hands of fleet testers and monitored/used by real life prius drivers who will give the general public a true representation of what the technology can deliver.

 

+1 to everything PeakOil has stated.

The EBH has helped me get into EV-mode quicker than normal, for a (slight) boost to initial mileage. I think this will become more of a factor once winter is here and temps go way down - this is probably where I'll see the most benefit.

The biggest hit to my mileage is the fact that most of my driving exceeds the range of the L5 pack. I have the same issue with my work commute depleting the Hymotion battery before I get home and driving the last 5 miles in normal Prius mode, which affects my mileage negatively and brings me down to 70-80MPG for the home commute. I also do a lot of driving to Boulder and farther places, which also pull my average well below 100MPG. On my shorter commutes I have seen well above 100, with a high of 177 so far.

Even though I have recently noticed an increase in the range of my L5 pack (I mentioned this in my Yet Another Hymotion Install thread), I still regularly drive beyond its range. I think it comes down to this: If your commute is within the range of the pack, 100-150MPG (depending on terrain and driving style) is very easy to achieve. Driving outside the range of the pack will most likely net you 70-100MPG, again depending on terrain and driving style.

Believe me, I'm thrilled with the results I'm seeing and to me it has been well worth the expense to be one of the first with a real Plug-in Hybrid. Hopefully all the early adopters will help to bring the costs down to a more reasonable level so more people can afford to have this mod done, and to help manufacturers bring turn-key models to the public.

Its great to be able to wave at gas stations as you drive by...:hand:

 

Posted another followup in response to comments:

 

100 mpg? how about 1000 mpg? What a useless, sensationalistic, headline! If you have a big enough battery, and drive a short enough distance so that the gas engine does not turn on, then I could give you a 100,000 mpg car (I assume some of the gasoline would eventually evaporate along the way).

Do these mag writers think we are morons? What is the TOTAL ENERGY COST per mile? That is what we need to know. In other words, on a long trip, what is the cost of electricity used to charge the battery AND gas used to supplement that. Last time I looked, my electricity was not coming in for free!

Sheez!

 

For me its 3.3 cents per mile.

 

A few of observations, as an owner of a Prius with a Hymotion conversion.

1) My wife and I seem to be getting about 90 MPG overall, for the driving we do, so far.

2) Driving style has a larger effect on gas mileage for a PHEV Prius than for a stock Prius, for a simple reason. The electrical system puts out a low, baseline level of power. Within the limits of the system (battery size, 34/41 mph limits), how much gasoline you use depends on how little power you demand above the electrically-supplied baseline. Your lowest level of gasoline use is zero, your highest is pretty much like a stock Prius, and what you get on average depends on the extent to which you keep the peak power demands down.

So, the folks who got 60, I'm betting a) they drove with a heavy foot, and b) they're the type who can't get 40 out of a stock Prius.

3) But a lot of that variability in gas mileage is due to factors that are unique to the Prius conversion. It is, after all, a retrofit. A more powerful electrical side, fewer limits (34 mph/41 mph for EV mode), or for that matter doing this with a serial hybrid such as the proposed Volt -- all of those would allow you to use electricity for more of the average mile and would reduce the extent to which realized gas-only mileage varies with driving style.

What I'm saying is the fact that some people manage to get mediocre mileage with a plug-in Prius shouldn't be used to judge the entire plug-in concept. What you're mostly seeing is the limits of a retrofit to a car that was not designed to be used this way.

4) Even with the limits, I really like the PHEV conversion. I particularly like driving around town in pure EV mode.

5) The Hymotion conversion never was likely to pay for itself (I figured I'd need 17 years of daily driving at $5/gallon gas to recoup the cost). But even with $2/gallon gas in the short run, battery cost might come down enough to make this a paying proposition. At $2/gallon, 10 years of daily battery depletion would save you close to $2K in fuel costs (depending on what you pay for electricity). So to put this in at the factory as a $2K option, that would pay for itself. It's not beyond the pale to think that sort of cost reduction may be feasible. The answer to cheap gas may be cheap batteries.

 

as much as they understand the Prius, they also missed a lot as well...

1) they acknowledge that the tank fills are not accurate and the MFD probably is.

2) ROI is not the point here

3) their numbers could be better


but lets face it... NO MATTER HOW WELL YOU DRIVE, you can mitigate the numbers anyway you like....they got 70 mpg at 46º...heck i can make it 60 mpg no problem.

the longer the drive, lesser is the impact hymotion provides.

let me test drive the hymotion... lets see my numbers on my daily 15 mile RT commute....