car shopping, geek shopping, energy geeking

[bolson]

Probably gonna buy a car between now and August. The $24000 for a new 2011 Prius is starting to sound reasonable. The pure-electric cars aren't available and have lame range*. The Chevy Volt is too expensive. Other hybrids get lesser efficiency and aren't as nice.

Also, I realize I shop for cars like I shop for gadgets. Lots of window shopping on websites and pricing out packages and features. Toyota's configuration page falls somewhere between Apple's (easy) and Dell's (way too much crap and way too long). But I'm definitely not going to be picking out a case-motherboard-cpu-etc and assembling them myself or whatever the equivalent would be in car land.


* Energy. 1 gallon of gasoline has 115000 Btu of chemical heat energy, at perfect energy conversion that would be 33.7 kilowatt-hours. We could cut that in a third as a rough estimate of energy conversion for an internal combustion engine. The Nissan Leaf and Ford Focus Electric have 21-23 kilowatt-hour batteries. If that's 2 post-conversion gallons of gasoline (a pretty small tank) and they have a range of 100 miles, they get about 50 miles per gallon. I'd call that normal for an efficient car these days. Now we just need batteries with the energy density of gasoline. Also, five miles per kilowatt-hour is about the same as my electric scooter gets.

Comments

[starphire.livejournal.com]

So, assuming a car that gets 50 miles per gallon of gasoline is "normal for an efficient car these days", I'm curious where you would actually be able to buy such a vehicle - in this country, anyway. I mean, as a hypothetical it sounds reasonable, but for car-buying decisionmaking this year, I'm kinda scratching my head on this statement.

[soong.livejournal.com]

Okay, I have a somewhat slanted view. The Prius officially gets 51/48 mpg city/highway. Official EPA MPG ratings are subject to being nonsense, but I'm hoping they're at least a consistant scale that can be used in comparison shopping. "normal for an efficient car" means the Prius or the earlier Honda Insights (I remember early models being supposed to get 60mpg, now they're around 40). Since these things have been possible for 5+ years, I consider the rest of the industry to be slacking off and being laggards and worthy of ridicule for being proud of 30mpg (which in my mind, was a normal car of 20 years ago). I recently rented a 40mpg Ford Focus for a weekend, it was an okay smallish car. This fall Ford is supposed to come out with an electric version of that car, and I suppose with regenerative breaking and a few other tweaks they could get it up to the neighborhood of 50mpg or equivalent m/kWh.

[starphire.livejournal.com]

Ah, I noted you were considering a Prius at the start of the post, but I think I was tripped up by "internal combustion engine" and "miles per gallon", thinking you were referring to a group of non-hybrid gas-only vehicles as candidates for your car of choice. I know there are several out there that get around 40mpg, but I didn't think they were as good as 50mpg yet, at least for a car that can seat 4 adults and pass all US safety and emissions requirements.

[genuinekfc.livejournal.com]

The Prius officially gets 51/48 mpg city/highway.

That's at 45-50 mph. My parents Prius is *great* for small state highways. It gets closer to 25 mpg at the usual 70+ mph on interstate highways. How you drive is more important than what you drive.

What percentage of highway/city do you typically drive? As stated below, diesels are excellent for sustained higher speeds, although you are also spending more per gallon of fuel and have to pick careful mixtures in cold winter months. The traditional gas engine with 6-speed transmissions are good for lots of flat highway driving, but loose their advantage if the highway has hills.

[soong.livejournal.com]

The car will typically be for a few miles a day around town, with occasional 200+ mile weekend trips.
Of course when I put it that way, it almost doesn't matter what I get. Most anything will be good enough. I should look around for bargain used cars. But my parents always bought new and held the car for 10 years and so that seems a reasonable model to me. And buying a car for 10 years makes me again care about wanting to get a good one that is just right.

My parents have reported sustaining 40 mpg at highway speeds in their Prius. Maybe there's an element of how they drive in that too.

[genuinekfc.livejournal.com]

I'm also from a "drive it for 10-12 years" family. I agree that buying new will probably win over buying used in long-term repairs costs if you plan to own it for that long. (Although hybrids are about $8k more than similar cars in the same class. Gas would have to be ~$8/gal for it to be financially worth it, depending on your tax incentive options.)

It looks like you are already focusing toward the more reliable models. I might also point out comfort. My parents had to add extra cushions and lumbar support to their 2004 Prius seats for long trips. Anyways, it sounds like you have a reasonable plan for getting to drive the types that you are interested in, and finding out which car annoys you the least.

[soong.livejournal.com]

Yup, worked this out in my next post

[mangosteen]

I can get about 44-45 mpg with my VW Jetta TDI, if I'm doing mostly highway driving. My worst-case mileage with it is around 29mpg (5 miles, stop-and-go, never warming up, etc.).

[starphire.livejournal.com]

That's something! Since I've been driving (as little as possible) a minivan that only gets around 20mpg for some years, and rarely have need for all that space anymore, I've been thinking about what I'd want to get for a smaller, more efficient car for occasional trips.