GRA
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GCC: Actual fuel economy of cars and light trucks: 1966-2017

Mon Sep 30, 2019 7:09 pm

https://www.greencarcongress.com/2019/0 ... sivak.html

These numbers are for the entire fleet, not just new vehicles, through 2017. We're up to about 22.3 or .4 mpg as best I can eyeball the graph. What about PEVs?
Even if all 755,000 plug-in cars and light trucks that were sold in the U.S. through December 2017 were still on the road, they would represent only about 0.3% of all registered cars and light trucks in 2017.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

powersurge
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Wed Oct 02, 2019 2:58 am

That graph does not represent reality. It is a politically manipulated instrument. It only talks about the FLEET>>>

That does not mean that our gas mileage has only been raised to only 22 MPG. Overall, 22 MPG is crap. We have cars that get 30 to 40, even 50 mph on the road.

The problem is that the car companies are still allowed to produce gas sucking military vehicles for the ignorant soccer moms to drive Escalades, and the redneck macho guys to roar past everyone in their Raptors. Those cars get under 10 mpg.

We need to wake up... You want to lower greenhouse gasses? make it politically incorrect to own those smog machines.

I know. Make gas $6 a gallon, and then they will start making more EVs. Then watch the mad rush to the dealers.

GRA
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Wed Oct 02, 2019 7:17 pm

Michael Sivak has been providing the average new car MPG for years, first at UMTRI and now independently, and it's been bouncing around at 25 mpg +- a bit for several years now. I specified this showed fleet mileage because that is what it does. To say that the fleet doesn't represent reality is ludicrous, as it's certainly far more realistic to base the average fuel use on the entire fleet than on the roughly 7% or so of cars that are new each year. Any big improvement in the average fleet mpg will take more than a decade, as it would take about 15 years just to replace the current fleet, assuming each time a new car was bought an old one was taken off the road, which isn't what happens. Indeed, as the average age of the fleet has been increasing for years and is now up to 11.8 years, we know that one-for-one replacement isn't happening.
Last edited by GRA on Sat Oct 05, 2019 4:48 pm, edited 1 time in total.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

GRA
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Thu Oct 03, 2019 5:59 pm

Also see: https://www.greencarreports.com/news/11 ... since-2008 which covers the same story.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

powersurge
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Fri Oct 04, 2019 10:20 am

I said that the "fleet" average does not represent reality because in the past, the average was low because the majority of cars had gas mileage that were closer together than now. Most people drove cars - - - Not SUVs, and the mileage average had a closer, smaller "standard deviation".

Today, we may have a similar "Fleet" average, but that is because there are much higher gas mileage cars on the road getting 40+ mpg, but too many people are bringing down the average with the sub-15 mpg gas hogs... We did not have that 20-30 years ago.

So today's "Average" mpg is not the same as the 1990-2000s "Average".

css28
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Fri Oct 04, 2019 11:13 am

@powersurge, please explain this Reality thing that you're talking about.

So the averages are constituted differently from the past--how does that make them less real?
- Chris
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powersurge
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Tue Oct 08, 2019 8:16 am

css28 wrote:
Fri Oct 04, 2019 11:13 am
@powersurge, please explain this Reality thing that you're talking about.

So the averages are constituted differently from the past--how does that make them less real?
Well, what I am referring to is that an average for a group does not always represent any "useful" information about that group.

For example you can get an average yearly income of a group of 200 people, of $50,000. This would be where 100 people make $40,000 and 100 people make $60,000. HOWEVER, you can also get a group of 200 people where 100 people make only $10,000 and the other 100 people make $90,000. The "average" is still $50,000, but the group is highly different, and none have an income of $50,000.

When it comes to the vehicle averages over the years.... Years ago, people drove cars that got gas mileage that were relatively closer to the other cars on the road. Today, we have people who drive high mileage cars, while many are willing to drive huge truck-cars (which are highly wasteful of gas). So that graph may show a slow increase in gas mileage over time but not accurately reflect the "average" number.

GRA
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Tue Oct 08, 2019 6:07 pm

The average person is now driving a CUV instead of a car, albeit a smaller and more fuel efficient CUV than would have been the case a few years ago. You've still not explained how that number doesn't represent the reality of the average fleet mpg. That the makeup of types in the fleet has changed over the years isn't the issue - we all know that it has. But what you seem to be saying, to take an absurd example, is that the moment the very first Prius entered the fleet it immediately became the average and represented "reality", and all the existing non-Prius' were at the ends of the curve and thus could be ignored when considering "reality", which is ridiculous.

The "useful information" about the U.S. fleet average is that the average fuel efficiency of all existing, licensed vehicles was 22+ mpg at the end of 2017.
Last edited by GRA on Wed Oct 09, 2019 6:18 pm, edited 1 time in total.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

SageBrush
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Wed Oct 09, 2019 6:13 pm

GRA wrote:
Tue Oct 08, 2019 6:07 pm
The "useful information" about the U.S. fleet average is that the average fuel efficiency of all existing, licensed vehicles vehicle was 22+ mpg at the end of 2017.
.
Your calc presumes equal use.
Better I think to calculate VMT/fuel_consumed for the fleet
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GRA
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Re: GCC: Actual fuel economy of cars and light trucks: 1966-2017

Wed Oct 09, 2019 6:17 pm

Sure, if you want to calculate actual fuel usage, and ideally you'd also want to break it down by VMT per type/mpg. Each additional variable considered will add to the accuracy. But that's not what the article was about, it was looking at the average 'book' mpg of all vehicles in the fleet, not their usage.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

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