The dirty cost of one man's hypermiling?

[MetroMPG]

Originally Posted by SentraSE-R

...so sought after by some hypermilers. The hypermilers who purposely choose pre-OBDII cars so they can swap older, higher-polluting engines in and strip heavy OBDII junk out.

Hypermiling = driving techniques.

Choice of car = choice of car.

Mods = mods.

Separate items, I would say.

The thread title is unnecessarily broad and inflammatory, something I'd expect to see in certain mainstream media, or on other forums/blogs that want to broadly bash the entire concept of saving fuel.

Note I'm not disagreeing with the ideas in your post. Just the "throwing the baby out with the bathwater" generalization of the title.

[user removed]

Darrell, while we have bumped heads a few times here, I truly appreciate the integrity of character demonstrated in your candid post. To reveal a problem that would affect your philosophy of conservation reflects a level of honesty I rarely see in this world any more.

As some have suggested maybe a change in technique, although I know it will directly impact your considerable mileage achievements. It is truly a dilemma.

Suggestions;

Insulate the cat to increase average temperatures.
Make sure the oxygen sensor preheating is working properly, possibly applying the preheating even before start up.
Although I hate to advise this maybe increasing the run time, with careful monitoring of the cat temp to keep it above the threshold of function.
That's very few miles over a considerable period of time, maybe a few more miles, road trip or something that would "clean her pipes" so to say.

Another way to think about it although you may not really be happy with this.

Most people drive a lot more than that, so in that respect you are already contributing much to lower overall emissions, and all cars emit much higher emissions on cold starts, so others who drive much more than yourself probably emit the same when you consider the combined effects of their short trips with numerous stops and cold restarts, something you have probably reduced dramatically or eliminated altogether.

I know my Altima would go into closed loop in about .3 mile, so it may be the best solution is to modify your driving to maintain minimum cat temp for proper functionality, combined with a few trips of some length to purge the cat itself.

I truly hope you can find a happy compromise, but your issue is a direct result of vehicle design that requires wasteful operation for lower emissions as a percentage of exhaust volume. You are reducing the total exhaust volume dramatically by minimising wasted heat energy.

It is one of the most interesting topics here I have read, keep up the good work, and don't beat up yourself. Imagine if everyone was as diligent as yourself. In the same time period I have driven many times more miles, which make me the greater polluter, if that would even make any difference to you.

regards
Mech

[MetroMPG]

Originally Posted by SentraSE-R

Insight I with their high NO emissions, so sought after by some hypermilers.

This is getting off-topic, but I'm curious about your comment re: "high NO emissions" of the first generation Insight.

It contradicts what I've read about the car, which was rated ULEV with the manual transmission and lean-burn.

ULEV = "emits 50% less polluting emissions than the average for new cars released in that model year."

[Andrew63]

Originally Posted by Old Mechanic

I know my Altima would go into closed loop in about .3 mile

What does this mean?

[MetroMPG]

When an engine with computer emissions control is first started up, it's in "open loop" mode, where the engine runs on quite a pre-set, rich air-fuel mixture. Once it begins to warm up (including the oxygen sensor(s)), it goes into "closed loop" mode where the air/fuel mixture is set by input from that sensor, and goes from running rich to stoichiometric (14.7 to 1).

Oxygen sensor - Wikipedia, the free encyclopedia

The faster your engine goes into "closed loop" after start-up, the better for emissions & fuel economy.

[cfg83]

SentraSE-R -

Originally Posted by SentraSE-R

...

I know today's cars burn much cleaner than older cars, but I lived through pre-Clean Air Act smog conditions, and I don't like the idea of my car dumping out 3-15X the average air pollution when it's driven normally. I can only guess how bad it is with an unlit cat.

So, P&Gers like me are gross polluters. Lean burn Hondas (including some Insight Is are polluters. The pre-OBDII cars are polluters.

I'm disillusioned by the growing realization that pollution is the hypermiling community's dirt we're sweeping under the carpet.

I remember the 1970's smog alerts in LA where I had to stay in the classroom. It was hard to breathe near the *beach*, no less, so I understand your sentiment.

Here is my question. What are the *total* emissions over the whole commute? The problem with this is that in order to find this out you can infer the emissions from sensor data, or you can rent or install an onboard emissions analyzer. For this reason I started this thread in 2007 :

http://ecomodder.com/forum/showthrea...ensor-316.html

I was interested in lean-burn at the time, so I wanted to know the NOx.

It's also one reason why I converted my non-heated 02 sensor into a heated one :

http://ecomodder.com/forum/showthrea...2-a-10921.html

However, that doesn't actually do much. I would need to reprogram the firmware in the ECU/PCM to take the mod into account. This is almost impossible with my car.

CarloSW2

[SentraSE-R]

Darin, I'm bothered by your perception of the thread title as unnecessarily broad and inflammatory. I meant for it to be controversial and attention-getting. How about a compromise change to "The dirty cost of hypermiling," "The dirty cost of my hypermiling," or "The dirty cost of one man's hypermiling?"

Re: the Insight I comment, I lumped it with lean burn cars in general, and in error. CARB barred lean burn Honda models from sale in CA in 1991 because of their high NOx levels. As you correctly pointed out, the MT Insight I was ULEV, producing 50% of the NOx emissions of normal contemporary autos.

Mech, thanks. I appreciate your compliments and suggestions very much. I do average a relatively normal ~10k miles/year with the box, with several road trips/year. My xB is a closed loop fool. Once warmed up, it's virtually always in closed loop. 98% load acceleration? Closed loop. Pulsing after a 5 mile EOC? Closed loop.

[rmay635703]

Originally Posted by SentraSE-R

I know today's cars burn much cleaner than older cars, but I lived through pre-Clean Air Act smog conditions, and I don't like the idea of my car dumping out 3-15X the average air pollution when it's driven normally. I can only guess how bad it is with an unlit cat.

So, P&Gers like me are gross polluters. Lean burn Hondas (including some Insight Is are polluters. The pre-OBDII cars are polluters.

I'm disillusioned by the growing realization that pollution is the hypermiling community's dirt we're sweeping under the carpet.

Are you really createing 15x the pollution getting double the fuel economy?

lets think rationally. The pollution you create has a weight that is directly associated with the amount of fuel you burn. The dirtier the burn the LESS weight of the pollution but you end up with carbon and aeromatics.

So your imagination is polluting.

The reality is your overall QTY of all pollution is lower, PERIOD, the amount of certain exotics that are a very small percentage of the makeup of your exhaust are larger.

I wouldn't get too cracked up over it.

NOx by itself is a non-issue.(when combined with other pollutions in a city it is) We regulate the heck out of it but it will degrade in the environment as do aeormatics and heavier emissions, heck A WATER MIST IN YOUR EXHAUST WILL ELIMINATE NEARLY ALL NOX, if you are worried.

Carbon Dioxide in of itself does not degrade a plant must convert it. I disagree with the BS of what we feel must be regulated in pollution and how in our pollution controls, especially in rural situations.

So I think you are worrying about something that isn't that important.

Afterall your exhaust and pollution levels are probably STILL 100x cleaner than the people driving 4x4s around wisconsin, including me in my cobalt during sub freezing weather on short trips. I doubt my CAT reaches operating temp on any of my trips with or without P&G in the winter and usually I don't P&G in the cold because its too hard on my battery and motor. not that it matters on short trips anyway.

If I were you I would worry more about the overall cost, does P&G cost more to you in maintenance than if you did not?

Are you REALLY polluting more than the average american driving their large 4x4 on short trips in sub zero weather?

I bet not.

[mechman600]

If you are pro P&Ger with EOC, shut-off at stop lights, etc., chances are good that you will be running the engine 50-60% less than "normal", depending on many factors. So if the cat isn't quite hot enough and your car is polluting twice as much ppm than normal, very rough math has your overall net pollution remaining the same with a sharp reduction in CO2. If you look at the actual readings before and after in the post #1, the overall ppms of nastiness are not even close to twice as much in the first test.

I would argue that slightly higher ppms on a smog test because of monitors not being ready is far outweighed by the 50% reduction of the "m"s (in ppms) being created.

[California98Civic]

Old Mechanic and cfg83 suggest ways to mitigate higher emissions from a cool cat (pun intended). I like the idea of finding ways to mitigate the problem.

But how much of a problem is there? Does a CA smog check report fully correspond to what our cars are really doing on the road as far as emissions? The smog check is designed to measure what a car will emit when continuously running, right? But P&G and EOC mean the car is off quite a lot. So the test overestimates what actually comes from a hypermile car during an hour and a certain distance, no? The total emissions of our cars may be more than a normally driven identical car in some categories of pollutants, or it might be less, when the overall daily emissions are considered. We can't know for certain until we know a few other things about your driving. If our cars burn no gasoline 50% of the time because they are being driven through EOC, shouldn't we consider halving the numbers on our emissions reports to get a rough sense of what we might be emitting on our way to work?

Although the OP raises doubt, there are doubts about the doubts too. Seems like a perfect scenario for methodical investigation. We need test equipment and a test method.

One could test techniques and mods that attempt to mitigate or even improve overall emissions during a given commute using P&G and EOC and such. If overall emissions are less than a smog check indicates because P&G means the car is off at times, then couldn't an occasional mile or two of steady-state driving during your commute keep the cat warm enough that the overall emissions might be about the same or, who knows, maybe less than an ordinarily operating car? What mods would go along with technique (such as insulation for the cat)?

My car's cat is next to the block and attached to the exhaust manifold, so I imagine it gets hotter faster and stays that way longer, especially since I have completely blocked the grills. No cool air blows directly on the CAT. What else could I do to keep it warmer? Is overheating a possibility?

james