Why SUV fuel economy is so much more important than small car fuel economy...

[SVOboy]

...and why any truck owner who wants to increase their mpg is a friend of mine!

Disclaimer: I drive a small car, I love my compact, and I always encourage everyone to do with the least they need (when it's feasible I much prefer my bike to my car). This is not about slamming people for buying a Civic Hybrid or a Civic VX for better economy; this is about contextualizing the issue and understanding why it is so important for the ecomodding community to embrace people with all sorts of vehicles.

Take a look at this picture:

From the thread inspiring article found here.

Just from this image, you can see that the MPG is a bad mark of measuring fuel consumption. Numbers like 60MPG and 70MPG sounds impressive (and they are), but their distance from, say, 30MPG is much less important than something like 18MPG.

Because of the steep slope of the graph in the lower MPG range, each MPG is "worth" a lot more than the MPGs on the higher end of the graph.

The original article demonstrates this point thusly:

I'll use some rough numbers to illustrate. You trade in your Civic, which averages about 32 miles per gallon, and buy a Prius, which gets a whopping 47 mpg. You've bumped up by 15 miles per gallon -- a big deal, right?

Sort of. Over the next 15,000 miles of driving, you'll have reduced your fuel consumption by 150 gallons. That's fine. But consider what happens when you upgrade your SUV. That's where the real action is.

You swap out your Dodge Durango (16 mpg on average) for a Toyota Tacoma (23 mpg). It's an upgrade of just 7 miles per gallon. It seems tiny. But consider that over the next 15,000 miles, you will have saved 285 gallons of fuel

Keeping this in mind, it becomes clear that the European L/100KM system is much more useful for direct comparisons. However, as long as most of us are using the US system (I wouldn't forget our members in other parts of the world), please do keep in mind that the improvements people with "guzzlers" make are very important to moving away from an oil based society.

And perhaps, just perhaps, if we're always remember to wear our kind and helpful hats, those SUV drivers may end up in a compact one day, taking an even bigger step away from fuel consumption!

[bondo]

Interesting perspective, gallons per mile. The distance will always be there, it is the fuel that is the biggest variable. One thing we must overcome in America, and I have encountered this posting messages on sites like www.fordf150.net, is that some people think that by conserving we are giving up our prosperity, which has no logic at all. Too many SUV and pickup truck drivers drive like they are in a compact car. They accelerate fast, drive over the speed limit and then wonder why they make frequent stops at the gas pump.

The big three marketing has been SUV's and pickups for many profitable years but those days are over. As China and India increase the demand side of things, the overall supply will not be able to keep up. Just look at SUV and truck sales these days, way down.

[AndrewJ]

yep, I was just doing some calcs.

If you've got a Hummer H2, you get 10mpg, and like the average American you drive 15,000 miles per year.

So lets say you hypermile the thing and manage to get 11mpg out of it.
That's only a 1mpg improvement, 10%.

But it'll save you over 136 gallons of fuel in one year, that's over $475 here in California.

[cfg83]

bondo -

Originally Posted by bondo

Interesting perspective, gallons per mile. The distance will always be there, it is the fuel that is the biggest variable. One thing we must overcome in America, and I have encountered this posting messages on sites like www.fordf150.net, is that some people think that by conserving we are giving up our prosperity, which has no logic at all. Too many SUV and pickup truck drivers drive like they are in a compact car. They accelerate fast, drive over the speed limit and then wonder why they make frequent stops at the gas pump.

The big three marketing has been SUV's and pickups for many profitable years but those days are over. As China and India increase the demand side of things, the overall supply will not be able to keep up. Just look at SUV and truck sales these days, way down.

I *think* I understand this thought process when I look at changing societal attitudes toward obesity :

Fat once revered as sign of health, wealth
And being scrawny was viewed as a symbol of a struggling life
http://seattlepi.nwsource.com/nation...oorthin09.html

... Only the rich had access to enough food to gain large amounts of weight during most of human history, said Dr. David Cummings, an obesity researcher at the Veterans Affairs Puget Sound Healthcare System and the University of Washington, who incorporated the slides into his talk. ...

If you don't live long, pigging out makes sense :

Life expectancy
http://en.wikipedia.org/wiki/Life_expectancy

Life expectancy at birth in the United States in 1900 was 47 years.

In a way, they're right. I would agree with them and say that our prosperity *is* diminishing. The difference is, I think we can conserve today on the road to a new era of prosperity :

A Solar Grand Plan
http://www.sciam.com/article.cfm?id=a-solar-grand-plan

By 2050 solar power could end U.S. dependence on foreign oil and slash greenhouse gas emissions ... High prices for gasoline and home heating oil are here to stay. The U.S. is at war in the Middle East at least in part to protect its foreign oil interests. And as China, India and other nations rapidly increase their demand for fossil fuels, future fighting over energy looms large. In the meantime, power plants that burn coal, oil and natural gas, as well as vehicles everywhere, continue to pour millions of tons of pollutants and greenhouse gases into the atmosphere annually, threatening the planet.

The above article may be pie-in-the-sky on some levels, but I think there are solutions "out there" to be (re?)discovered and applied.

CarloSW2

[Stan]

Good food for thought.

I have a diesel Excursion that I use pretty much exclusively for work (hauling supplies and parts internally, or pulling a 24'x8.5' enclosed trailer). It gets nearly 25 mpg at 55, but only about half that pulling the trailer. I drive it about 10,000 miles a year, but those tend to be longish (300-4000 miles) trips at highway speeds where it would benefit the most from even modest aero mods.

I gotta put some thought into this.

[MetroMPG]

Really well put, Ben.

"MPG" is a truly terrible metric for discussing fuel economy. When you consider how many people can't (or don't even bother) to calculate their FE, you just know that the finer points of the "MPG issue" are completely lost.

A giant pet peeve of mine is reading about people's changed MPG out of context. E.G. "I inflated my tires and got 3 mpg better last week!"

It's a meaningless statement unless you also tell me what your base MPG was. Yet you read that kind of thing, without the additional needed info, all the time.

[MetroMPG]

BTW, this issue is directly related to the Click and Clack puzzler I posted about a while back.

[mossman]

What a fascinating and mind bendingly mathmatical concept. It sure makes me feel good for driving my V6 Ranger at 22% over EPA. One thing I felt that the people commenting on the original article overlooked is the fact that all these trucks and SUVs are already out here. Even if you get all of the owners to switch to compacts or hybrids, what are you gonna do with all the trucks? Landfill them? And what about the impact of manufacturing all those new cars? Grand visions of a hydrogen or electric future are great, but in the mean time we need to get the most out of what we have now! I was gonna get a motorcycle to reduce my footprint a bit, but now I think maybe a dump truck driven carefully may have a bigger impact.

[jamesqf]

Originally Posted by mossman

Even if you get all of the owners to switch to compacts or hybrids, what are you gonna do with all the trucks?

1) Park them until you have an actual need to haul a load, or drive on a rough dirt road or deep snow. I have a pickup ('88 Toyota) which gets driven maybe a couple thousand mile a year - and a lot of that is cutting firewood for my wood stove, so one tank of gas saves several hundred gallons of heating oil.

2) Sell the worst offenders off for scrap metal. One Hummer could yield enough recycled steel for several Priuses :-)

[TestDrive]

I find it most intuitive to think in terms of larger intervals like Gallons Per 100 (or 1000) Miles. (Least amount decimal shifts and divisions, mostly just plus, minus and multiply.)

Conversion Table: GP100M to MPG in 0.5 gallon increments.
(GP100M = Gallons Per 100 Miles & MPG = Miles Per Gallon)

GP100M	MPG	-----GP100M	MPG
0.5	200.0	5.5	18.2
1.0	100.0	6.0	16.7
1.5	66.7	6.5	15.4
2.0	50.0	7.0	14.3
2.5	40.0	7.5	13.3
3.0	33.3	8.0	12.5
3.5	28.6	8.5	11.8
4.0	25.0	9.0	11.1
4.5	22.2	9.5	10.5
5.0	20.0	10.0	10.0