I have found that I am going out less because of gas prices. I already have an economical car (37 gpm on highway) and live fairly close to good backpack areas (most trips are within 200 miles), yet I am hesitating. I think it is the sticker-price shock factor. The best way I can see to reduce gas price is to carpool (this implies that I need to find more backpack partners). I am also delaying buying new gear. I also am thinking about trade-offs - for instance skip the fishing (out of state license at 80$ buys about 23 gallon of gas or about 850 miles - that's almost pays for the trip to Wyoming if I decide to go to the Wind Rivers).

Also the gas prices are not just directly applicable to my backpack mileage. I am now spending more on gas for non-backpack reasons, leaving less for backpacking. I have been using the equivelent of a backpack trip's gas to see my new grandson weekly, the equivlent of several trips to fly to see my elderly mother and the equivelent of LOTS of backpack trips to fly across the country to see my newest granddaughter. I am really torn.

I also wonder if I should bit the bullet and do my farther away trips this summer betting on even higher gas prices next year.

Gas here today is $3.60 per gallon and going up fast.

How are you all handling this?

It's starting to get noticeable. I don't need my little truck to get to work - I ride my bike. My truck gets 30mpg. I've got a granddaughter 450 miles away and I just plan accordingly. I guess the jump in fuel price has caused me to plan more, not do less. I think I would curtail a lot of non-essential expenditures before I would give up driving.

For those around in the 78 fuel crunch, it wasn't the price of gas that was the problem, it was the availability. Where I was living they had odd/even day gas rationing. Fortunately I could ride my bike to work then, and still do now.

Gasoline prices are so visible but they are a relative thing.
As a teenager, gasoline was priced at about .29 (yeah I'm 62 now). My wages went up along with gas costs. During the 1960's the gas mileage of most cars was under 20mpg. Today's vehicles offer improved mileage as you know. By my estimate I can travel farther today on a gallon adjusted for inflation than 30-40 years ago.
Just the same I try to drive efficiently & plan ahead to economize. I drive a 2002 Subaru Outback & with synthetic oil the mileage is 29mpg on a good day.
I likewise have sons & granddaughters living on the other side of the U.S. Cheaper to fly then drive to see'em.

But it makes little sense to drive a few hundred miles to walk 10 or 20, does it?

Well, I don't have much choice up here in Alaska where I'm at. I have to drive at least an 40 minutes to find any trails. I'll have to do the same when I go back to Boise also, though there I'm hoping to bike places a bit more. But, I'll still drive the half day to Yellowstone or the full day to Glacier to hike for a few days or for a week. The sights are more than worth the price, though I'd rather get there in a more economical and eco-friendly manner. The gas prices will probably decrease the number of long distance trips though.

Yep. I feel it twice; out of my pocketbook AND my wife constantly reminding me to cut down on miles. I bike to work every day which might help a little (unless there’s snow on the roads).
I always carpool w/ backpacking trips and my groups vary between 3-6 unless we’re with scouts.

I remember NiytOwl bringing this up a couple years ago: http://www.backpacking.net/forums/showth...rev=#Post107905

Wow! Long link. Hope it works.

-Barry

I just bought a house that is 40 minutes from work. Luckily I also found someone else who works the same hours and at the same place, and lives in the same little town that I do, so we carpool. We are looking at a third person (hopefully).

I am going to say something a little controversial, and maybe off topic. Even though I pay a lot for gas, I hope the price keeps rising. Why? <img src="/forums/images/graemlins/confused.gif" alt="" /> Because then it would force change. At the price right now, it is only inconvenient. We do a little economizing, drive a little less, and really don't change much. <img src="/forums/images/graemlins/blush.gif" alt="" />

For me, No, but then again the "rising gas prices" are more of a USA phenomenon - it's been over a buck a litre here for a while, and while it's been going up some, it was already high <img src="/forums/images/graemlins/smile.gif" alt="" /> - but for me it really comes down to the time to go is more hard to come by than the money right now - so by the time I can go, I just spend what it takes on the gas - I'll carpool/bus/bike to work instead.

The only time I suppose I really get bitter about it was like this weekend, when I ended up
being forced to bail out early on, and so spent about 80 bucks on gas for what amounted to a lot of driving and not a lot of being out <img src="/forums/images/graemlins/frown.gif" alt="" />

Yeah, gas prices have changed things for me. At my awesome 8-10 mpg, my drives are limited. Luckily, I'll be digging out my motorcycle before long and bumping that number to about 40 mpg.

I put about 12K miles per year on my car. At 25 MPG, that's about 480 gallons per year. Going from $3 to $4 changes my gas cost from $1440 to $1920 per year($120 to $160 per month).

One thing that has enabled me to reduce the number of miles I put on the car has been the addition of a 100+ MPG moped. But I can only really drive it maybe six months out of the year. I put a few thousand miles per year on it.

These costs alone would be easily containable. But the cost of gas creeps into everything. So I cut back on unnecessary trips and keep my purchases to the necessary.

When it's time to take vacations, I tend to stay closer to home to cut back on the travel expenses.

It's not a major concern for me. I'm lucky enough to live near work and I only work 3days/week. I often bike or run to work. Sometimes I go several days without driving a car at all.

By saving money on my work commute I feel less guilty about spending money on gas for trips.

And yes, every cloud has a silver lining. I hope that increased gas prices will result in cleaner air, less congested roads and less dependency on foreign oil. Drivers will become more efficient. Many of my work buddies drive huge SUV's or pickup trucks to work. Most never haul anything or even see so much as a dirt road.

Since its between 5 and 25 miles from my house to ski, <img src="/forums/images/graemlins/wink.gif" alt="" /> bp, 4wd, fish, etc, it doesn't matter much. <img src="/forums/images/graemlins/smirk.gif" alt="" /> BUT I wish my business truck was a motorcycle but I couldn't haul compressors and ladders too easily. <img src="/forums/images/graemlins/blush.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" />
Jim <img src="/forums/images/graemlins/cool.gif" alt="" />

I gnash my teeth, call my congressman and yell, blame Bush and Cheney a lot, and tell all my friends and neighbors that voted for "Oil Men" that they're to blame too.

So, all in all, I'd say I'm handling it pretty well.

I'm doing even better this morning because I just watched a mini-movie by Shell Oil that's running 24 hours a day on Dish network right now. It's a real drama, with romance, and forest fires and all the hard work they do to get us the energy we need. I give it $$$$ Up!

Bill

It isn't just gas prices. It's the price of everything that requires petroleum products for growing (food), shipping, etc. Plus the increase in prices of anything from overseas due to our incredible shrinking US dollar. It's especially fun when you're on a fixed retirement income, as I am. I got a temporary respite this year (which about offsets the inflation of everything else) by getting a cheaper (i.e. higher co-pay) Medicare HMO plan, but if I should get sick that could really come back to bite me!

I am making less trips to Seattle to see the grandkids (I am going this weekend, my first trip since mid-January), going out to the Columbia River Gorge to hike only once a week (much to the detriment of my training because there are no significant hills in my neighborhood), and trying to combine all shopping/errands/church trips into a single outing as much as possible.

I still plan one trip to the Rockies this summer. I am obligated to a week's backpack in northern Colorado and decided to tack on an 8-day trip into the Wind Rivers (thanks to wandering daisy's trip reports!) right after that. I will reduce motel expenses by camping at the trailheads at both ends of each backpack trip, so that I have a total of only two nights in motels for the entire time.

I managed last year to knock 2,000 miles off my annual mileage by going home after work instead of driving around for something to do. I put 20,000 miles on my truck the previous year, so I did cut back on a couple weekend trips and made money by cutting firewood to sell to pay for car insurance on my car that sits in the garage while I cut firewood and deliver it.:( Go figure. I don't let the price of gas cut into vacation plans, something I plan on and I save by staying out in the boonies close to the trailhead on vacation trips.

Wandering Daisy, there is a small but busy group I belong to that do a lot of bping and dayhikes to the coast and into the mountains, most of the members are down in the bay area/Sac area vicinity. I go when they have trips closer to me in the Sierra. We are doing a trip to Lassen VNP this coming weekend, about eight are to show up I believe. Most are carpooling, we have been a group for 4 years now. One or two post here some. A trip or more a month through out the year, with many posting very good photos.

I have a newish car that gets very good mileage, but with gas prices up & my payments almost finished I'm thinking of picking up a scooter or small motorcycle for commuting. They often get 50-70+ mpg, and if you get the right one you can even take it to the trail. Otherwise, I've been carpooling to the trails as usual. I make up for my increased gas bill by not driving as much during the week.

I've been into energy conservation for decades but saving money is only one of my motivations. Still, 'back in the day', I cancelled a trip from San Antonio to the Everglades because gas prices got so high...they were up to 45¢/gallon! <img src="/forums/images/graemlins/shocked.gif" alt="" /> A few months later I realized that the marginal cost of that jump in prices would have added $65 to the cost of the trip. There's no way I should have given up a two-week trip to the Everglades for $65...

I agree that gasoline prices seem high but if you calculate how much this year's trip costs vs. what it would have been last year the sticker shock is tempered a bit. If it's still too much consider changing driving style. There's usually a big savings to be had dropping the speed from 75mph to 65 or less. Similarly, air conditioning, which generally sucks up a lot of gasoline, usually isn't needed in the early morning hours...

I too grit my teeth over gas prices today but I don't cancel 'trips' because of it. The sad point, IMO, is that for Americans gasoline is still too cheap...there's been little change in demand...little conservation resulting from these high prices. My neighbor still fires up the SUV to drive the mile and a half to the country store to buy the newspaper and chit chats for twenty minutes or so...while the vehicle idles. Three hours later the first mile and a quarter is repeated to pick up the mail. That behavior and the other idling cars I see at the store tell me that gasoline price isn't an issue...yet.

FB

I have a 50 cc Honda Metropolitan, which gets about 100 MPG. The only drawback is the top speed of about 40 MPH. If you need to go faster, look for something in the 125-150 cc range. They still get 75-80 MPG, depending on which you get. And they can do 50-60 MPH.

The other drawback with a scoot is when the weather sucks. Nothing stings quite like a cold rain at speed.

I try not to let the price of gas cut into my BP'ing. I have a 4-cylinder Toyota pickup I use on trips that gets around 30 mpg so I don't feel too much pain there. A lot of my neighbors feel the need of F-350's and their ilk (10-14 mpg?).

The gasoline cost of my getting to the trailhead has increased here by about 20% and I am offsetting that by running most of my errands using my moped. I have a Tomos moped that will get between 100 and 120 mpg, depending on headwinds and does 31mph tops.

I live on a small acreage in the desert between Tucson and Nogales; over ten miles to the nearest store and eight miles from the Post Office. No public transportation. Getting groceries and mail would be expensive without the moped. I take a pack with me and plan on a slow, pleasant trip into town. Unless there is a really big load to carry, this is how almost all the errands are handled. I am also on a more-or-less fixed retirement income and have to watch expenses. At least I don't have the expense of commuting to a job to deal with!

Just an FYI........there is a device called a tornado that creates a vortex in your engine from the air intake. This allows for better gas mileage because the gas/air mix is better (or so say all the manufacturers of these things). There are a bunch of different companies that make these things, the particular one I have is here: http://www.tornadoair.com/ , but I'm sure other ones work as well. It is very easy to install (I am not a car guy, but it was extremely simple for me to install it). With the amount of driving I do, it paid for itself in one year (and that is when I first bought it, with around $2.10 gas). With gas only going to get more expensive, these are definitely a relatively cheap way to become more fuel efficient. The only thing you have to watch out for is getting the right size for your particular make/model/year.

It will be a crap shoot as to whether or not this device will help for a given model. For most modern vehicles, I'm willing to bet it would actually be detrimental. At least the very least, it may help for some conditions and hurt for others. Engineers put a lot of effort into optimizing charge motion these days. If there were such a device that could be put into the air stream that would improve fuel economy across the board, we'd be using it.

I believe the actual principle this tornado device operates on (differentiating it from the countless others marketed over the last quarter-century) is that it creates a vortex over your wallet causing dollar bills to spiral out of it. <img src="/forums/images/graemlins/wink.gif" alt="" />

Fuel Economy Devices

PC:

from that fuel devices article:



. . . that's appropriate.

Total Cr$p! I get soooooooo tired of hucksters dumping this stuff on suckers. Of course, PT Barnum is proved right all the time, so maybe I should just let the parasites feed and the hosts feel good about their fuel-saving purchase.

That device has been proven worthless. If it worked, auto makers would have installed them in vehicles. You get what you pay for. You could try chipping the computer but a lot of the newer autos cannot be improved on by just chipping.

Wow, I guess I'll just reply to myself since four of you have decided to rip me a new one..... I really couldn't care less if you save money or not. All I am saying is that I used to religiously track my miles with every fill up before and after I got this, and it improved my miles per gallon, enough so to pay for itself in a year.

Anyway, I'd rather not let this thread drift...interesting reading

Paddy_Crow is right. I was a car builder for about 18 years. During that time I was exposed to all the water injectors, whirlygigs, pour-in potions and add-on gizmos people could come up with.

The biggest efficiency advances in internal combustion engines in the last couple dozen years are electronic fuel injection and ignition systems coupled with the "Brain" and sensors that interact with and control them.

I been driving a little old Suzuki Samuari 4X4 for close to twelve years now. I even "Customized" it a few years ago. I put a sticker on the windshield that says, "BUMMER". I always look for a "HUMMER" to park it next to when I go to town. <img src="/forums/images/graemlins/grin.gif" alt="" />


Bill

The cheapest and most effective fuel economy device you can get is an egg. Put it between your foot and the gas pedal before you start out on a trip and try not to break the egg. Seriously though, the most effective item for fuel economy on any given vehicle is the driver! I have seen statistics suggesting that the average American could gain 20% in fuel economy if they were just to change driving habits.

I also recall reading an article on "gas saving" widgets such as water injectors and the "turbines" you mention. BTW, they were available when Model A Fords were new; the same claims were made then. The conclusion was that any fuel savings were due to changes in the way the driver drove after the device was installed. Also, there was seldom any data on fuel mileage before the device was installed so any "improvement" could not be rigorously documented.

Rant-
Is has for years now. Before the 2000 election(?) I had a discussion about what would happen with George as Pres and we concluded that gas would go up 2.00 per gallon. Never did I imagine that it would go this high.
Everytime a Yukon Denali passes me doing warp factor five I just have to say 'thanks'.
Yes it has affected my trips and if I did not live where I do I am not sure how I would cope. 60 miles to a dog friendly wilderness. 50 miles to this side of the Smoky Mountains. And several other areas still within reach. I have considered a motorcycle or a stripped down Subaru as alternatives. I thought about getting a tiny little pickup and striping down to the bare bones, sorta UL style. Like cutting the tags off your clothes, but to the extreme. But if you do the math on specific 'hiking' vehicle with insurance and maintenance it is hard to justify it. A motorcyle would most likely get stolen and are not dog friendly.
I am sure that if you took all the unnecessary equipment off of an already fuel effiecient vehicle that it would only get better mileage.
Why is no one doing this? I could even sacrifice the radio and ac to get more savings at the pump.
If Subaru/toyota would make one of their more fuel efficient models in a super efficient model with all the safety features, but none of the fluff I would buy one. I would also imagine that it would cost less with less of the comforts and amenities -the spoilage.
My wife is from Germany and we got an email the other day that (already converted) their gas was $ 8.00 american per gallon. So look out. They are not done with us yet. One day gas will be only for the rich. And I have children that will not get to enjoy the freedoms that I did.
But how about minimum wage people that are just trying to survive and feed their families? How about a single mom that has to tell her kids that there is no dinner because she has to get enough gas to get to work and back again. Maybe some billion dollar CEO could give her some of his left overs, or let her root around in his trash. I'm just saying...

If you go back and read my posts objectively, I think you'll agree that they were not disrespectful.

I've been designing auto engines for more than 25 years, in that time I've tested more charge motion inducing devices than you can imagine. Bottom line, they tend to improve combustion at low speeds but the increased drag tends to be costly at higher speeds. Thus you'll find most modern engines that use charge motion inducing devices have a means of switching them on and off.

Without turning this into a dissertation, my guess is that this device can provide a marginal improvement on a carbureted or TBI engine if you keep the revs down. With a multiport injected high swirl or tumble engine, I bet it would hurt fuel economy. I would be interested to hear what data you've collected and on what type of engine. Also curious how much improvement you claim the device is delivering.

Sorry, I am a skeptic. I've seen many of these devices and tested them on dynamometer. I have yet to find one that lives up to its billing.

PS- you can put Slick 50 and similar oil treatments in that category. We've tested the daylights out of the stuff, it provides absolutely no benefit whatsoever. The early stuff was even detrimental, it clogged oil filters.

I have to agree with Paddy_Crow again, and also say that I did not mean to be ripping on you.

I was not an engine builder. I became a "Metal Man", I built car bodies mostly, and occasionally the chassis they sat on. But all those cars needed an engine so I got to know several highly respected engine builders and I learned when I was young to pay attention to the guys that were really good at what they did.

For grins, you might want to do some more testing using Paddy_Crow's advice. Test at both city and highway speeds with and without the device and see what you get.

I for one would be very interested to know since my little Suzuki Samurai has a throttle body fuel injected carb and it might benefit from the device according to what Paddy_Crow says. I very seldom go fast or run at high RPM's, but with that little 1300cc engine it doesn't seem to matter how I use the accelerator, it gets 25mpg no matter what. (When the 'Sami' was completely stock it got 30mpg. Bigger tires and lower gearing in the transfer case cost me the 5mpg)

Bill

Somewhat.

We own two SUV's and a sedan.

The SUV's:
One 2000 Ford Explorer we are trying to sell. It gets 16-20 mpg. A grocery getter but works well in snow, etc.

2000 Nissan Xterra that has been used for off roading. Not sellable. Gets 12-14 mpg on highway due to being lifted and carrying a ton of extra steel. Offroading gets it maybe 10 mpg. Keeping as...well, only a few people would want its well abused body <img src="/forums/images/graemlins/tongue.gif" alt="" />

1993 Mercedes Benz Diesel sedan. It gets 32-40+mpg depending on weather and what grade fuel we use. We run B5 to B20 Biodiesel in it and it likes that a lot better than dino diesel. On highway we top 40 mpg. She is a huge sedan as well - no economy car here - she sits 5 real sized adults with a ton of gear. But! She is not good in snow or cold weather so we drive the trucks during the winter when hiking up in yonder foothills.

The Benz allows us to travel still and it is actually getting easier to find B99 Bio as well. We are considering putting the conversion in as well this year so we can run bio alongside WVO "fuel" at the same time. With this we could drive to Montana and back on ONE set of tanks of fuel. Currently we fuel up around the 500 mile mark to be sure. I love our Benz more than any car I have driven. I will NOT go back to a gasoline car again. Diesel is the way for me.

I forgot to add....here where we live, you have to have emission testing done every 2 years. The Benz scored in the top scoring this year. What that means is our big girl doesn't pollute a storm up (people think diesels and black diesel bombs coming out). The bio fuel is very helpful.

More and more firms here put up "economical driving" classes for their drivers (busses, trucks, car fleets,...), aiming to save up to 20% on fuel, as the gallon is way over 5$ for us . For some people, it's really "drive or feed the kids" now.

Some day, the rest of the US will realize this. Now, we just need a hybrid diesel. Man, that has got to be an expensive motor. <img src="/forums/images/graemlins/grin.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" />

All I need is a diesel station wagon and life would be good <img src="/forums/images/graemlins/laugh.gif" alt="" /> I also bought a bike recently for doing my daily mail runs for the business - our post office is moving soon and I won't have to bike on main roads, all back roads to get there <img src="/forums/images/graemlins/smile.gif" alt="" /> It does involve two hills though, both ways and my bike doesn't have a latte holder <img src="/forums/images/graemlins/laugh.gif" alt="" />

I am with Paddy as well. I don't have 25 years in the industry, just a four month senior level college course, Internal Combustion Engines. It was taught by a guy who was trying to get out of the engine industry and into teaching. He had over 20+ years of engine research at Southwest Research Institute. Basically, engine designers are trying everything they can think of to optimize the fuel/air ratio.

As an alternative, you could always ask the mythbusters. <img src="/forums/images/graemlins/grin.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" /> Sometimes their test method is a little shaky, but most of the time they do a good job. <img src="/forums/images/graemlins/wink.gif" alt="" />

Two words, "insulated camelback". <img src="/forums/images/graemlins/wink.gif" alt="" /> <img src="/forums/images/graemlins/wink.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" />

Lol...but how do I stay a yuppie if I don't have an insulated latte holder on my handlebars? <img src="/forums/images/graemlins/grin.gif" alt="" /> Just have to watch the potholes while drinking....does this mean I need to put away my cell phone as well? <img src="/forums/images/graemlins/grin.gif" alt="" />

Be careful with high bio content fuels, it can be unhealthy for engines. It causes problems with injectors coking and doubles the rate of lube oil oxidation (and that's on B80). I would advise frequent oil changes, don't try to push it past 5000 miles.

We stay with lower Bio rates - B99 doesn't run as well in the cold, it can "gel" up. On the other hand we take care of our Benz. B99 won't hurt it. We have a mechanic that only works on Benz's and his specialty is diesels. Bio run diesel cars are very popular out here. The majority of diesels can handle B99 that is made well - the fear is well, inferior fuel and that a certain number of trucks don't like the Bio's.

One big issue you do have to look out for is when you go to B99 is your fuel filter will get mucked up fast. We had to change ours out even with B20 after a month or so. Now it is great. Dino diesel is not so hot for diesels - it doesn't do the lubrication it used to be able to! A little bio in it is nearly always good.

Sarah:

How many hands have you got? Glad you have bio-diesel out there. Here we're a good decade, maybe two, behind you. And with all the fried foods they eat in Florida, we're literally swimming in something we could be burning in our cars.

The thing I've noticed here in Florida is the huge jump fossil-fuel diesel has taken. The Shell station at Calle Ocho & I-95 -- a landmark spot -- had regular gas at 3.49 and diesel at 4.39! That would somewhat negate the effect of the better mileage one gets with a diesel car here.

Very true on Dino Diesel....it is running $4.00 to $4.40 a gallon here - makes the Bio versions actually affordable now! For me, the extra cost in fuel still works out - nearly 40 mpg in the sedan vs 16-18 in the SUV <img src="/forums/images/graemlins/wink.gif" alt="" /> Regular cheapie gas is still pushing $3.70 here as well! Pricey no matter how you go at it. Ugh.

Note to self....if wanting to run WVO in my car go to Florida. No one will be fighting me for it <img src="/forums/images/graemlins/laugh.gif" alt="" /> It is getting competitive out here in some places for the used fry oils! Many places have collection drums out back with if you look some ones name on it <img src="/forums/images/graemlins/wink.gif" alt="" />

The majority of OEM's are just beginning to test their diesel engines on bio. The issues I mentioned were uncovered by that testing, but it's still preliminary. We really don't know what the consequences may be for long term use.

A few SAE papers I've read indicate there's no significant difference in lubricity between refined diesel oil and those with bio content.

I have a Ford Ranger and I've asked if they make them with a diesel engine. I was told they do but they only sell them in South America due to emissions.

I would really love to have a small pickup truck with a 4-cylinder diesel engine.
Remember the VW Rabbit? I drove one of those for a few years and loved it.

As for a scooter, no way am I driving one here in the DFW metroplex. That would be suicide. It's bad enough in a small car, dodging all the trucks (18 wheelers), SUV's, and big pick ups. (I have one of those too, but don't drive it much. Only when I have to take 4-6 people).

For now, it's not the fuel prices that are keeping me from going backpacking but the job.

All right, so you were just telling me from experience, not ripping me…..fair enough

I have absolutely no idea what you just said there, you lost me when you said TBI engine <img src="/forums/images/graemlins/confused.gif" alt="" />. I can understand your skepticism, especially considering your background.

I have an automatic 1994 Saturn SL1. The driving is a mix of city (<45 mph), highway (45-60), and interstate (>60) miles, with more city and highway miles than interstate. The actual Excel spreadsheet I used to calculate this is on a fried computer in the closet, but I remember whenever I did calculate it I got just over 1.25 extra mpg. So I went from around 33 mpg to at least 34 mpg (again, I can’t recall exact figures; this was a few years ago and the actual receipts are long gone…I did it for about 8 months after I got the device to compare to prior fuel economy, and calculated it would take about a year to pay for itself). So using 1.25 and 33 mpg, that equates to a 3.8% improvement. You were curious as to the engine type……http://en.wikipedia.org/wiki/Saturn_S-Series says I have a SOHC 1.9 L I4 LK0 engine; whatever that means to you.

And like sarbar, I too have to get an emission test. I live in a certain 26 (I think) county area of metro-Atlanta that you have to get an emission test every year, and I’ve always come out with flying colors, so this isn’t just some old junker (well, maybe it is, but it is my old junker).

Pika: There are probably a lot of variables I wouldn’t think of that affects the gas mileage, but I know that my driving habits will change the fuel economy the most. I could easily bias what I am saying one way or the other (whichever way I choose), but all I can say to this is that my driving habits have not changed.


P.S. Have you seen this http://www.youtube.com/watch?v=QmqpGZv0YT4 and what do you think of that?

TBI = Throttle Body Injection

Not many cars were TBI after the late eighties. The first wave of replacement for carburetors was single injector in the throttle body, followed by multi point injection in the intake runners. The reason I brought up carbs and TBI is that turbulence induced upstream of the throttle plate will be pretty much dissipated by the time it gets to the injector in a long and curved intake runner (multipoint). I also doubt there will be much turbulence remaining just downstream of the throttle plate at small angles. So the window for such a device to positively affect mixing is not wide.

If you measured your fuel economy over 8 months, I suspect there are seasonal effects in your data. Things like humidity and temperature will affect the efficiency of the engine. Also, some parasitics like air conditioning are not consistent from season to season. The condition of your air filter, engine oil, and filter will also introduce variation in your data.

Also, there are seasonal variations in gasoline blend with more of the volatile, lighter fractions being used in winter and more of the less volatile, heavier fractions being used in summer. The heavier blends tend to produce somewhat greater fuel economy which tends to be offset by more use of air conditioning in summer. Also, in a lot of cities, methyl ether and/or ethanol are added up to 10% of volume as an air quality improver. Both of these additives tend to reduce fuel economy.

These things don't work. Mythbusters have debunked a few of them, although I don't think this particular one. On the other hand Popular Mechanics reviewed it, and I'd probably trust them to tell me it's just a another nice bunch of snake oil sold with internet flash.