I have been reading more and more references to GM's electric car, the Volt. It sound like a fine car, but there is some question as to how the average person is going to find enough outlets in their house to plug in 380 required AA battery chargers at once. Just kidding. Here's an overview on Wikipedia. I'm no car engineer, but one obvious problem with the design (based on the below photo) is that it's using wheels that are larger in diameter. Smaller diameter wheels are more efficient as they have less mass. Plus, how aerodynamic could the wheel design be anyhow with that angular pattern? Shouldn't the wheels be designed to have the lowest wind resistance? Obviously they have to have a car the looks appealing to the eye or no one is going to buy it, proving that those California enviromentalists still favor form over function.
I'm planning a road trip to the Dallas area this weekend, so it will be a perfect chance to see how the Jetta performs on the highway for a long trip. I have a feeling that I'll get about 45 MPG on the highway, although as my wife likes to point out, we'll have the AC on which will impact things. Maybe it'll be in the upper 30's. We'll see.
I have been logging my daily MPG figures regularly for a while now. I need to post the updated figures. One thing I realized is that if I only take a short trip one day, for example, to the store, then I will have an artifically low MPG figure compared to my daily trips to and from work. What I realized is that it's important to know how many miles were traveled when looking at a MPG figure. For example if I drive 2 miles for the day and have a 25 MPG figure, that's a lot worse than if I drove 20 miles and hit 42 MPG. The good news is that my short drive-low MPG figures are rare, so they won't skew the overall numbers much. The other way to go would be to pay more attention to the per-tank MPG figures, which would represent 3 or 4 weeks of driving and would be a better representation of the car's overall MPG versus each daily figure. I'll have to start recording those. I still believe I'm getting around 37 MPG with my normal driving. Some days I get 40 or 42, but most days I'm hitting around 37.
One other thing that always strikes me is how much idling kills the MPG. I hate sitting at a light and literally watching the MPG figure drop, 1/10 of a MPG every 30 seconds or so. The flip side of this is I pretty much know what MPG the car is capable of on average, so I don't worry too much about the specifics.
One final story: I was driving my usual route to work and had a passenger van tailgating me for about a quarter of a mile along a long stretch of freeway access road. I was in the center lane, and kept waiting for the van to go around me like any normal person would do. I was coasting up to the light because I knew there was no way it would turn green before I got there, so there was no reason to burn extra gas to get there. Eventually the driver of the van honked the horn, gunned the engine, changed lanes into the left lane, and went around me. The driver then proceeded to stay in the left lane, stopped at the light, waited to make a left turn, and then made a left turn at the light after it turned green. Why in the hell did the driver stay behind me all that time, only to have to change lanes anyway? And why did she stay behind me all that time and then honk only before changing lanes? None of it makes logical sense. I can understand that some people don't want to get behind a car moving slower than theirs, but 99.99% of people have the sense to change lanes as soon as they see the slower vehicle ahead.
On a non-hypermiling note, I did replace the radio antenna base which fixed my AM radio reception problem. Now I finally have AM radio. Thank God for the person who posted this on the Internet so I knew which part to replace. I think Germans tend to overengineer things; why in the world would you put an electronic circuit board inside the base of the radio antenna, especially when this part is outside of the car? (it sits on the roof). The classic problem with this part is that water seeps inside and corrodes the electronics and kills the AM reception. Luckily the $35 part was easy to replace.
On the way home from work yesterday, I saw a person in a Prius. One of the front tires was visibly low on air. I had a flashback to the misconception that hybrid drivers are all a hypermilers. Nope.
What happened to the tire? I can think of a few possible scenarios: It is possible that the tire has been punctured recently and had suddenly lost air. It is possible that the tire had a slow leak and had been getting losing air for several days or weeks. Or perhaps it was just suffering from chonic underinflation. The rear tire on that side didn't look visibly low, but even a 10 pound loss of air pressure isn't always visible.
Whatever the scenario, it underscores the concept that most people who are looking for the highest MPG cars still need something that is toaster-simple to use. Additionally, the car should get high MPG under average conditions which includes underinflation.
Two years ago in Houston it was uncommon to see a hybrid car. Lately, however, these cars are very common and not hard to spot during a drive through town. I used to be surprised to see a hybrid car blowing past me at high speed because I assumed that most hydrid owners were hypermilers and would be driving an a similar manner to me. This appears not to be the case.
After pondering this for a while, I realized that most people want high MPG without having to change their driving habits in major ways. People buy hyrbrids knowing they're going to get higher MPG, and they expect the cars to deliver the stated mileage. In other words the car has to change; not the driver.
Certainly the major automakers realize that people want to drive in certain ways, and its the cars themselves that are going to have to be re-worked to deliver high MPG. Any car that requires the driver be a hypermiler isn't going to sell in enough quantites to turn a profit.
I suppose in the long run if there is still a large demand to lower transportation costs people will learn to drive in a more conservative manner, but people still expect cars to work in an appliance-like manner: turn the key, hit the gas, and go.
We took a 400 mile road trip in the Jetta and I was eager to see how the gas mileage was going to look. Unfortunately there was a leak due to a broken clamp on the boost pipe, and that killed the mileage. We only hit 30 MPG on the way there, and the way back yielded a lousy 15 MPG. The problem has been repaired and I clocked 41.3 MPG on the way into work this morning which is in line with previous figures.
I like to think that the boost pipe leak was a problem that was hampering the mileage figures for a while before the road trip, and that I might be able to pull sligtly higher numbers going forward. The 41.7 figure from this morning was really good, and that was on my usual route to work and included driving up to the 4th floor of the parking garage which sucked about 1 MPG off the average. The whole incident does offer proof that even a problem like a leaking hose can really hurt the efficiency of a vehicle. Modern engines and their plumbing, sensors, and other systems are complex. If everything isn't in the right place then something will suffer.
This page written by Steve Dutch at the University of Wisconsin-Green Bay is incredible. He uses real math in a discussion about how much work can be achieved with a gallon of gas. Even if you don't follow the numbers all the way, it's an interesting discussion of the math that goes on when you convert fuel to motion in a car.
tires
When buying tires in the past I never gave a thought to the fuel efficiency. My main concern was price, brand, and styling of the tire. Now, however, the issue of efficiency suddenly becomes important. I googled the subject of the best tires for hypermiling and came up with this interesting thread.
Certainly the tire companies are working now to produce tires that have a legimate edge in terms of MPG. It will be interesting to see what comes down the line. In my truck I could get 60K miles on a set of tires if I kept them inflated properly and rotaed every 7K miles. I expect the same thing in the Jetta, but I also want the tires to offer low rolling resistance and reasonable performance.
Driving in Houston during the hot months of March to September without air conditioning can be tough. It's not the heat that's so bad, it's the humidity. When the air is saturated with water, your body's own cooling mechanism of perspiration is much less effective because the sweat doesn't evaporate quickly. The evaporation is what causes the cooling. Therefore your skin tends to have a coating of sweat that doesn't go anywhere except into your clothes where it accumulates. The original intent of modern air conditioning wasn't to cool the air, but to dry it. Having an air conditioner in such a hot and humid city is a blessing and driving in the humid 95 heat is very uncomfortable without it. It's one thing to break a sweat on the way to the grocery store or a trip to the park, but it's a different matter when you're headed to work in slacks and a long-sleeved shirt. If you're wearing a suit or have to attend a high-profile meeting, then you're in trouble.
Use of an air conditioner really kills gas mileage. The compressor is the biggest culprit, but the fan also causes an impact too. What's my point here? One point is that society today expects certain things such as people that have no odor. This is one of a million small concepts that have been built upon the concept of cheap energy and other resources. I am not advocating that people go back 100 years in time, but I continually think about all in our lives that is based on cheap and freely-available resources.
We took a family trip across town this weekend to see The Orange Show, The Beer Can House, and Penzey's spices in The Heights. It was an interesting test because every seat was filled, we ran the AC the whole time, and we had some gear in the trunk. We did a good deal of freeway driving, but also did some stop and start driving in traffic.
Unfortunately I failed to write down the actual mileage before it was overwritten in the SG, but I remember thinking that it was about 10 MPG less than my normal numbers. So I'm going to consider it was a 30 MPG trip. This seems resonable considering that we did 50% freeway driving, and a lot of driving streets with no traffic and few traffic lights.
In other news, I checked my tire pressure on Saturday afternoon and my tires were all about 5 to 7 pounds low. In the truck, the tires did not deflate this quickly. My rear tires are rated at 35 PSI max and the front tires are 44 max. I filled them up this morning on the way to work and inflated the rear tires to 50 and the front tires to 40. This is probably pushing the limit of causing center tread wear, but we'll see. If they deflate this quickly, I probably need to fill them every time I put gas in the car, which means I'm going to have to pay more attention to the availability of air at the gas stations I like. I suppose this will be a growing concern for more and more people. Luckily, there is a gas station near my home that offers free air. All one has to do is ask the clerk to turn on the air pump. No purchase necessary.
I have been continuing to log my daily MPG figures and will post a chart shortly.
In the weekly Q and A automobile column in today's WSJ, the writer mentioned hypermiling.com. I was elated to see this because it helps get the word out there. The problem, of course, is that like all other mainstream media mentions of hypermiling, focus was on the dangerous and illegal techniques. Even the WSJ is not immune from the biases and use of sensationalism that the MSM holds dear. I certainly don't deny that some hypermilers are doing some dangerous and illegal maneuvers, but the standard techniques can work wonders for anyone and I believe that those are enough for 99.9% of hypermilers.
I took a trip out at lunchtime to pick up a couple of items and hit a record 47.5 MPG for the trip. The whole trip was made along the same freeway access roads I take to/fron work, so I knew how the lights were timed. I think I only stopped once during the whole trip. The trip to work in the AM was good with a figure of around 42 MPG.
According to the miles driven on my first full tank, the Jetta is running 31.4 MPG. I got about 400 miles from the tank. To achieve a 40 MPG average, I'd need to get 500 miles from a full fill up. I don't know exactly why my SG mileage figures are higher than my manually computed value, but here are some thoughts: 1) The manually computed value is not accurate, because it's difficult to know exactly how much fuel was used. 2) The SG daily average numbers I have saved by recording them on paper were cherry picked and did not include any non-commuting travel.
I have been logging my daily MPG averages. The 'daily' figure gives you the average of the whole day, not just a single trip. This is a more accurate overall figure because for me it includes short trips (such as to the pool or the store) which generally yield lower MPG figures. I'll post a table of numbers once I have more data.
Here's an interesting page about the California Commuter, a car built in the late 1970's that achieved a world record 157.192 MPG at 55 MPH on November 20, 1980.
I filled up the Jetta with a second tank of gas over the weekend and configured the SG accordingly which amounts to telling it how much you put in and how much was paid. (12.73 gallons at $3.93/gal). After that, my MPG readings were horrible. At first I thought it was the two short trips I made, but on the way in this morning the figures were about 3/4 or 2/3 lower than what I was expecting. Other than filling up, I had made no changes to the SG other than inputting the fillup data. I refused to believe that I was only getting 14 MPG on the drive to work while using the same techniques I had been using all along. That's the same kind of mileage I used to get in the truck which had a V8 engine and weighed 500 pounds more. Maybe I got bad gas? The engine appeared to be running fine. I had made no modifications to the car.
When I was about a mile from work I found the option to reset the SG to its defaults. I wasn't sure how much data this would reset, but I figured it was worth a try. I knew I could easily reprogram the settings I needed.
This apepared to fix the problem. During the remainder of the drive in I was seeing the kinds of numbers I was used to. We'll see what happens in the long-term. I'll see if I can find anyone else who has reported the same issue. I did find this in the SG manual:
Use the following sequence HOME>MORE>FILLUP>DONE. On
this first fillup after connecting the ScanGaugeII II, Don't adjust
the indicated fuel before pressing DONE>.
I didn't follow this, thanks to the poorly written manual. After I had filled up I was thumbing through the manual to find the fillup directions and never did see that. The manual doesn't tell you what happens if you do hit done.
The trip home with the SG was fine in terms of MPG. I was hitting the old numbers with ease: 37 MPG trip average (with a stop for groceries), 200 MPG coasting, 45 MPG Or so when cruising in high gear at moderate speeds.
On the drive in this morning I had a couple of thoughts. First, cruising along down a fairly open stretch of road at 45 MPH and 55 MPG looks good in terms of the instant MPG reading, but one has to keep in mind that 55 MPG isn't enough to offset the stage 1 losses from idling and acceleration; Stage 3 (coasting), where one can get 100 to 300 MPG figures spending on speed, is where the real gains are obtained (at least in my car). Being reminded of this on the drive in reinforced the need to pay attention to the road ahead and coast whenever possible.
Back to the public transportation low MPG issue, here's an idea: Incentivize bus drivers who obtain consistently high MPG figures. Certainly a standard-issue public bus has some ScanGuage-like capability that shows and stores MPG readings. While anything capable of transporting 50 people isn't going to get high fuel economy, certainly usign hypermiling techniques could show some gains.
Here's a neat app that calculates the price savings between two cars with different MPG at MPG O'matic.com. I was able to learn, for example, that I'm saving $9 a week with the Jetta to and from work compared to the truck. If I drive 8000 miles a year I'm saving about $1,000 based on $4 gas. With $5 gas I'm saving $1,350 a year.
Feel free to post comments at the bottom of the page.
June 30, 2008 - 8:58 PM
I wanted to comment on two issues I have encountered with the SG. First, the display gets dim when the unit is very hot. I encountered this today after the car had been parked outside in the sun. During my trip on the freeway I had the windows up and was not running the AC, so the SG had no chance to cool down. The display was dim and hard to read, and this was not a function of the backlights. I remembered reading something about this phenomenon, so I removed the SG from its mount and put it in the shade. Within a few minutes it was back to normal. Research on this confirms this is expected behavior. I guess the LCD just goes limp in the heat. This is one reason to mount the SG with velcro so it can be removed from a hot area of the vehicle when not in use.
The second issue is that the instant MPG will occasionally read "9999". This seems to happen most often when I shift gears, and it returns to a normal figure after a few seconds. Research on this also confirms this is common and may have something to do with the 'Fuel cutoff' setting in the SG. I will adjust mine and see if it changes the behavior.
June 30, 2008 - 7:48 PM
40.3 MPG on the way to work. This was my usual work location and the one where I will be traveling most often. A few thoughts:
When I tell people about the Jetta, usually the subject of MPG comes up. What do I tell them? So far I think I will make the claim that I can get 40 MPG around town with conservative driving. Based on my numbers so far I think that's fair.
To achieve high numbers, one needs a good stretch of road for coasting. Driving in stop and start traffic, or making a really short trip, is likely to kill your numbers. No big news there though.
Petroleum hit a new all-time high today. Articles in the WSJ this morning provided more evidence that the cost of transportation is changing everything such as moving production out of China back to the states and the changing of distribution systems to operate on a more reginal basis because it's just not profitable to move some products on a national basis. Instead, it's becoming necessary to produce and sell products locally in order to avoid transporting them really far.
When I was in the position to possibly buy a Jeep, my fear was that I'd regret the decision as the cost of gas continues to rise. I'm glad I made the decision to go with a more fuel efficient vehicle. An article in the paper reminded me that the cost of fuel has doubled since 2005. Anyone who bought an SUV 3 years ago expecting to pay $2.00 for gas is hurting. Even the Honda Civic owners are paying twice as much, but at least they're having to buy less gas. No wonder SUV and truck sales are in the toilet. It still amazes me that people are driving these hulking pickups with 6 liter engines, lift kits, 22" wheels, and a variety of heavy bolt-on bumpers and steps. I'm glad people have the freedom to choose, but it would not be my choice to get 8 or 10 MPG.
GM still doesn't get it. In the Sunday Houston Chonicle, there was a review of GM's new Escalade hybrid. No MPG or price was given. Certainly GM doesn't think it can return to profictability by selling such a vehicle! It will get what, 20 MPG? That's what their hybrid Tahoe gets. GM seems to think that if the word 'hybrid' is in a vehicle's name thene it's going to sell well. People are much, much smarter than that. I don't think GM is trying to fool anyone on purpose, but they're stupid if they think they can return to profitability with a 20 MPH vehicle! The Japanese-based companies, meanwhile, will continue to perfect their hybrids and sell loads of them. New companies like Smart will grab more market share. But we still see GM trying to get by selling SUVs. ha. What I see shaping up is the same thing that happened 25 years ago: The Japanese beat the Americans by providing high quality vehicles at a low cost. Now they're providing high-quality hybrids that provide true MPG gains at a reasonable cost. The Americans are 10 years behind, just like they were 25 years ago.
I stumbled across this article about how hybrids don'tl ive up to their MPG claims. It seems to confirm much of I've read in some of the hybrid discussion forums. I was commenting to Penny last night that companies will have a hard time selling a hybrid to the masses unless it drives and operates in a similar manner to a standard car. Otherwise, they'll never sell enough of them to turn a profit. The problem, of course, is that if you drive a hybrid like a standard car then you're going to get lackluster fueleconomy. This brings me back to the point I made here (and here) about how the mid-80's Hondas got better mileage than hybrids do. It's all about the low weight of the car and having a small engine.
I tweaked the SG this morning to show both realtime MPG and trip MPG at the same time. This adds to the game aspect because you can instantly see if you're above or below your average. If your realtime MPG is below your average, you feel pressured to improve. If it's above the average, then you know you're raising the average and boosting your score. Photo later.
I measured 37.9 MPG on the way in to work this morning. This included about 3 miles of freeway driving in moderate traffic at speeds of around 50 MPH. Entering the freeway was fun because I had to accelerate fast enough that the turbo kicked in which isn't something I've experienced much lately. I had clocked 38.0 MPG by the ene of the trip but lost a tenth of a point after traversing the parking garage at the end of the journey.
As I coasted into a parking spot, I was reminded of my grandfather Bob who had a '74 convertable Volkswagen Beetle. It was mayan green, which was yellow with a hint of green. I will always remember how that car smelled. It had a slightly tangy, oily mechanical smell, but the most prominent smell was hard to describe. It wasn't overpowering, it was just the smell of an older car.
They used to live in a house that had a long, long driveway. I will always remember riding with when he would shut the engine off about a quarter of the way upthe driveway so that he could coast in to the garage. That never failed to impress me when I was a kid. Bob always had an eye for savings and efficiency, but I don't know if he did this coasting maneuver to save a couple of pennies or just for the fun of it. He was eager to learn and would enjoy reading about hypermiling.
After examining a number of fuel efficiency graphs for different vehicles, it looks like most non-hybrid vehiicles have a peak MPG in the neighborhood of 40 to 50 MPG. I have mixed feelings about this. It suggests that I can't get super high MPG numbers on the freeway, however it means that I don't have to get on the freeway to hit peak efficiency; I can get it on a long stretch of road. Over time I should get an accurate picture of ther realities of the Jetta. Here's the graph for a 1986 Volkswagen Golf GTI:
June 26, 2008 - 8:45 PM
I took some photos of the ScanGauge II (SG2). Here are some pix with some explanations. The SG2 is simply a small computer and display that takes realtime data from the car's computer, makes calcuations with the data, and displays it for you.
The SG has 3 main display modes. The first mode shows you realtime stats. You can have it display whatever you want. This screen is showing MPG, MPH, engine RPM, and air intake temperature, but there are perhaps a couple of dozen stats it can show.
This realtime display is showing the trottle position, voltage, intake temperature, and gallons per hour consumption rate:
The SG can also give you data based on the current trip, the last trip, or yesterday's trip. This shows the gas mileage for the day:
You can also have the trip-related data display on the realtime screen. This would, for example, let you display both the realtime instant MPG plus the MPG for the trip. You could display the trip speed and the realtime speed.
This shows the gallons consumed for the day:
The SG also has the ability to give you 64 different backlight colors so it can match just about any dishboard light color. Here's a good one:
It's a fun and useful toy! It's very easy to use. The best part of the interface is that you can always hit the button circled in red to get back to the main screen.
June 26, 2008 - 7:40 PM
I managed to reach 38.7 MPG on the trip home. That's 84% better than the EPA estimate of 21 MPG in the city. Now I'm starting to see why some people are drawn to the more advancved hypermiling techniques such as stopping the engine at long red lights. I sat through at least one red light that made me wonder if I should have killed the engine. Interestingly, while sitting in my driveway waiting for the electric gate to to open so I could approach the garage, the trip MPG calculation dropped from 38.8 to 38.7; proof that idling does make a difference and that even small changes are needed to get a higher score.
The basic methods I'm using are:
Slow acceleration
Limiting engine speed to under 2000 RPMs
Coasting whenever possible
Using the highest possible gear at the appropriate speeds
Looking as far down the road as possible to look for traffic lights, stopped cars, etc.
Keeping a lengthy distance between the vehicle in front of me
Making very wide turns in order to maintain as much speed as possible
Anticipating traffic conditions and light timing based on my knowledge of the route
Not running the air conditioning
Tires are inflated to 4 pounds over their limit
Performed engine maintenaince (replaced oil, filters, plugs, etc)
I used to have the opportunity to drive on I-10 in Houston during the rush hour AM commute. While the traffic was poking along at 5, 10, or 25 MPH, it never failed that I'd see a driver who was hell bent on getting ahead by ONE car. These drivers would swerve and accelerate hard and brake hard always trying to get ahead by a little bit more. I also observed that most drivers didn't want to get behind large trucks, or 18-wheeler tractor-trailers. Why? People felt pinned in, and they felt like this would slow down their trip. What I observed was that these large trucks basically kept within a narrow range of speed because with a full load, it wasn't feasible to make quick stops and starts. A heavy truck full of cargo had a lot of inertia, so it was just easier to keep it rolling along at a consistent speed.
Why couldn't I do the same? I started driving like the trucks. In fact, I would often get behind a truck and let the truck to the work for me. This ironed out all of the stops and starts so I could just cruise along at a consistent speed. Over time, some cars might get 5 or 10 or 20 cars ahead of me by changing lanes and cutting in and out of traffic, but at what benefit? If a car is 15 feet long and has another 15 of space in front of it, these drivers were only 600 feet ahead of me having saved a handful of seconds. That's hardly much when you consider we're all driving for 5, 10, or 25 miles. I never had the chance to see that my consistent driving had eliminated all of the stopping and starting in front of me, but I always knew that my trip was a lot easier.
June 26, 2008 - 6:35 AM
The ScangaugeII came in yesterday. It's as neat as everyone says it is. I clocked 35.8 MPG this morning from my house to work (although not the same work location I usually drive to), driving on all streets in light traffic. I'm pleased with the 35 MPG because it beats the 21 MPG figure from the EPA by 70%. On long runs I was hitting 45 MPH and getting around 65 MPG.
The SG basically confirms my driving habits and gives me some real data. I still struggle with what to do at intersections where I know I can make the light if I drive faster.
I can't want to see what it can do on the freeway. I never did get the car up to a fast enough speed to confirm what my maximum cruising MPG is. While coasting at the higher speeds, the MPG was peaking at 175 or so which is neat to see and helps smooth out the low numbers seen while accelerating.
After the truck died and I ended up with a 2003 Volkswagen Jetta, I realized that it would be interesting to really see what kind of gas milage I could get. A friend reminded me about the concept of hypermiling which I had read about months earlier but never paid much attention to. After doing more reading, the concept sounded like a lot of fun. In addition to being somewhat of a game to achieve the highest possible score, it could also bring bragging rights if I could claim high MPG numbers. So, in order to document my learning about this I decided to start posting my experiments here.
The factory window sticker for my Jetta claimed fuel economy figures of 24 city and 31 highway. The DOE fueleconomy.gov website states revised figures of 21/28. We'll see what it can really do.
Some random thoughts:
Currently I'm about 1/3 of the way through the first tank of gas in the Jetta and have been using some of the general hypermiling techniques. So far the numbers look positive with an estimated 31 MPG with all city driving. This is equal to the highway milage figure from Volkswagen. I'll have much more accurate data after the scangauge is put into use.
The one thing that I keep thinking is that the highest MPG in a typical automobile seems to be achieved at a ballpark speed of 50 MPH, mostly due to increased wind resistance at the faster speeds. It will be interesting to see what I can learn with the ScangaugeII. Still waiting for it to ship.
One of the things I've had to get used to is cruising at 30 or 35 MPH in 5th gear. My Jetta owners manual confirms this strategy in general, adding that you will need to downshift in order to accelerate. I watch the tach more than the speedometer, mostly because when the engine is only turning at 1.2 or 1.5K RPM I can't hear it, especially if i'm moving at 30 MPH with the windows down and the stereo on.
On my 7 mile drive to work this morning, I realized that I'm probably using transmission gears a full order higher than what I'd normally use: Instead of waiting for 40 or 50 MPH to shift into 5th, I'm doing it at 30 or 35 and either holding my speed or increasing very slowly. Instead of running the engine around 2,000 or 3,000 RPMs for daily city driving, I'm keeping it between 1,000 and 2,000.
Penny is an anti-hypermiler (her term, not mine); not because she drives too fast, but because she does not coast or look far ahead at traffic conditions and routes. It's built into her brain that she is either pressing on the accelerator or pressing the brake. There is no in between. Even when approaching a red light she will touch accelerator if she's had to momentarily slow down for some reason. Another way to describe her driving is that she would alaways have the car moving somewhere around the posted speed limit up until the point of needing to be stopped, such as at a red light. Again, there's not much in between.
For most people who need to drive to work in a comfortable temperature and with a radio, the key to saving gas starts with the driver, not the car. While operating a fuel efficient vehicle is important to save money on gas, one can save money with whatever they do drive. Just as so-called jackrabbit starts will waste gas, slow and steady starts will save gas. This works with any vehicle.
