Eduardo Pelegri-Llopart's Blog

December 2004 Archives

Yes, I like my Prius

We got a new Prius about 5 months ago. Since it seems that at least once a week somebody asks me about it, I decided to write a longer answer...

To begin at the end: Yes, we like it very much and I would buy it again. It is not a perfect car, but it is a pretty good one, it gets great mileage and most of the tradeoffs of previous hybrid and electric cars are gone.

First about the mileage. We routinely get 49-50 mpg out of each tank, with a mix of in-town driving and highway commute. We took it backpacking to the High Sierras and we got 36 on the way up, a very cheap way down, and a total mpg of 49 for the whole trip. Speed matters: we took the car from San Francisco to LA; the first part of the trip was fast driving at about 80 and the mileage was about 43 mpg, but in the congested freeways of LA we got 57+mpg. Short trips will give worse mileage while the engine warms up, and cold weather also lowers the mileage substantially. Overall I'm very happy with the consumption. An extra bonus could be the new law on car pool lanes in California, although I don't count on it being approved by the feds.

The Prius has quite a bit of internal space for a car of its external dimension. It qualifies as a mid-size, and although the way the feds measure this is does not always translate into usable space, the seats are very comfortable. The front has plenty of space and headroom, and the back has a lot of legroom. The main drawback is that the headroom in the back is a bit limited because of the shape of the car; I am 6'2'' tall and touch the celining when seated at the back. The Prius is also a bit narrower than other mid-sized cars and that translates into a middle rear seat that is a bit tight. Both limitations are due to the desire for a good Cx (0.26).

As all hybrids the Prius combines more than one source of power; in the case of Prius a gas engine and an electric engine. Hybrids can be parallel or series; the Prius is parallel in that the two systems can work independently. For example, once the engine is warmed up it is quite common to run on the electric only in city driving. The hybrids from toyota (prius, and soon to be lexus and highlander) and ford (escape) all are parallel hybrids. The honda hybrids (civic, insight, and accord) work in seriers: they use the electric engine to help the gas engine and can't run on the electric only. Both systems shutdown the gas engine when stopped (as in front of a traffic light) and use regenerative braking to charge the battery thus improve mileage. In general the toyota approach can deliver better gas mileage (although the lighter Insight has the best mileage of all) but the parallel systems are more complicated than the series ones. I have only driven the toyota, so I can't compare, but I like being able to drive in electric mode only.

In general the power and pickup of the car is more than adequate for my needs. It accelerates well (0-60 in 10 seconds) specially from 40 mph or 60. In our trip to the Sierras, we carried 5 people plus luggage in a rack [a yakima loader on top of thule mountings] and we were doing 65 going up; the engine was a bit noisy, but we didn't have any problems.

The Prius is pretty well equiped for its price. We have the middle of the range model and we paid MSRP price for it. It comes with wireless ingition (which I love - my keys stay in my pocket all the time now) and ABS and VSC as well as side airbags. The finish is very good, and, so far, we have not had any problems with it.

From what I've heard from other people, the current Prius is much better than the previous model. There are only two negative areas I can mention: one is that the transition from regenerative braking to standard braking could be smoother; the other is that the car is a bit too affected by cross-winds if you run with the tires inflated extra. The first is not a biggie to me; when I worry about the second (like in the road to San Luis Reservoir) I reduce the pressure on the tires.

If you want more details, there are a number of good website. John has a good site that includes a very useful Users Guide. Other prius resources include forums and a yahoo group. A couple of other general web sites are hybridcars.com and hybridcars.about.com.

So there you have it, a longer version of "yes, I like it". It is not a perfect car, but it is a pretty good one, and this is one of those cases where you can think globally and act locally. The current Prius happened because the first generation sold well enough; the success of the current generation of Prius is likely to spark a wider adoption of hybrid technology around the world; and I am looking for a smaller, sportier, hybrid to replace our second car :-).

You should know about JavaOne Online

I meant to get this one out earlier but I got distracted with getting our JDLs and TCKs out and I forgot. Tomorrow [Wednesday (Dec 15th) at 10 am PT (GMT - 8)] Anita and Ramesh are giving a free webinar at JavaOne Online. You can register from the link at JavaOne Online, or directly at this link (if I got the URL right).

I rediscovered JavaOne Online a few months ago, and I think it is worth you checking it out. It collects all the JavaOne presentations since '02, not just the ones given at the conference but also the backups. It also has some extra presentations, not at J1, and I expect we will be doing more of that [for example, I am trying to arrange for a presentation giving an update on the JAX-RPC 2.0 and JAXB 2.0 specs] and it also includes webinars. The presentations are very compelling: you get a transcript, a PDF and an audio synchronized with the slides (via a Flash client). The whole thing is very useful: you can do a quick check through the PDF, listen to the whole presentation, or narrow into some slides using the transcripts and then listen for the portion you want to.

What makes the whole thing interesting is the cost. The webinars and the PDF presentations are totally free. The audio and transcript is not, but the price-point is right (IMO): $25/year, which is less than a technical book. The cost used to be quite higher but since they lowered the subscriptions have been pouring in. You may want to give it a try, they have a free tour (try-and-by) and they have pretty high conversion rate.

In any case, tomorrow's webinar is all free!

What are the JRL and the JDL licenses?

Some of you observant types may have noticed that some recent JSRs, like JAX-WSA list JRL and JDL in section 2.18, "Terms and Conditions". The JRL we knew, it is the Java Research License introduced at J1 '03. The JDL is a new license, the Java Distribution License. IANAL and all disclaimers apply, but, here is my operational micro-summary of these two.

JRL and JDL are much simpler that some of the licenses used by Sun in the past, like SCSL: JRL is under 2 pages, JDL under 4. Neither carries some of the most complicated clauses of SCSL but both remain committed to the Java compatibility requirement and are not, to my knowledge, OSI-approved. In a nutshell, the JRL is for research and internal use; the JDL is for commercial deployment.

The JDL licenses just started being available. The first actual deployments are JAX-RPC and JAXB, but Common Annotations for the Java Platform and JAX-WSA indicate they will also use JDL, and other specification efforts are likely to use JDL too. I expect that, as was the case with JRL, some of the details of the JDL will change as the requirements of other specs are folded into it and it is quite likely that we will end with several versions of JDL due to conflicting needs.

JDL grants the right to do changes and then distribute the result, provided the changes are compatible. Compatibility is defined through the specification and the Technology Compatibility Kit (TCK). Sun is making the JAXB and JAX-RPC TCKs available for free to be used to help test the compatibility of these RIs (and derivative artifacts) but that is not necessarily the case for all APIs placed under the JDL.

Hope this clarifies things a bit. I've been involved in the process for the JAX-RPC and JAXB versions of JDL and I believe they address those requirements that were not fullfilled by the JRL, but if I'm wrong, I'm sure somebody will tell me :-)...

JAX-RPC and JAXB now under the new JDL!

The JAXB and JAX-RPC projects at Java.Net develop the Reference Implementations for these specifications. The source code for these projects has, until now, only been available under JRL, the Java Research License. JRL is intended for research and internal prototyping and does not allow for modifications intended for deployments. This is a problem for those groups that want to do their own support, want to apply fixes without waiting for the changes at Java.Net, want to take the implementation into different directions, or just want a security blanket. It tooks us longer than I wished but we finally fixed this deficiency through an additional, brand-new, license, JDL, the Java Distribution License, and by providing new access to the associated TCKs.

The JDL allows modifications intended for deployment and commercial use. JDL is a much simpler license than some of its predecesors but it preserves the key JCP compatibility requirement centered on Specifications and Technology Compatibility Kits (TCKs). The version of the JDL that we are using in JAXB and in JAX-RPC includes the right to access the TCKs for these technologies. These TCKs are now also at Java.Net and can be used, free of cost, on the Reference Implementations and on artifacts derived from them to help test their compatibility.

The JAXB and JAX-RPC production-quality implementations are already used in products like the J2EE SDK and the different editions of Sun's Application Server, in the JWSDP, and in stable and weekly individual builds. The new JDL license and the availability of the TCKs will expand the applicability of these Java.Net implementations to those groups that feel they need to do their own - compatible! - modifications.

JSR for JAX-WSA just filed

There is a new JSR-261 for JAX-WSA: Java API for XML-based Web Services Addressing. This JSR was submitted by Sun with the formal endorsement of Apache Software Foundation, BEA DevelopMentor, JBoss, Novell, Oracle, SAP, Sonic Software, Sun Microsystems Inc. and Tmax Soft, Inc.

The JCP EC will be voting on this proposal in the next couple of weeks. If the proposal is approved, we expect a few additional members to have an EG that represents the interests of platform vendors, tool vendors and other types of users of the technology.

Sun, as the submitter of the EG, will be responsible for delivering the Reference Implementation, which we would do at Java.Net layered on top of the new implementations of JAX-RPC 2.0 and JAXB 2.0, as part of the JWSDP community, and with similar terms and conditions.

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