Quote:
Originally Posted by cowmeat
It can happen, check my fuel log for the proof! 100 mpg is so far behind me I can't even see it from here, and I'm just learning to drive my EV
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Yeah but we all know you're a good hypermiler. I'm talking about all the Stanley Stomp-n-Steers out there who don't know what they're doing.
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@Climate Denial:
The climate doesn't care what you believe. Saving gas isn't just a global warming issue anyway. I am an environmentalist and that's why I care about fuel economy, but it's also patriotic, and it saves you money. If it makes you feel better then this entire topic can also be talked about in the context of getting down to net 0 oil imports/exports.
2015:
US imported 2.68 billion barrels of oil, exported 0.17 billion barrels of oil.
US used 7.08 billion barrels of petroleum products, including biofuels (ethanol) total.
Imports were about 24% of total consumption, "The lowest level since 1970," according to the EIA.
Approx 19 gallons of gas and 12 gallons of diesel or heating oil were made from these barrels on average in 2015.
About 140 billion gallons of gas were consumed in 2015.
That 2.68 billion in oil imports, minus .17 in exports --> 2.51 billion barrels imported --> x19 gallons/barrel = 47.69 billion gallons of gasoline came from foreign sources last year.
So basically, that's what we're looking at from a "let's not give money to the Saudis and Venezuela" perspective. Although, I suppose if you wanted to take it further, you could break this down into countries because Mexico and Canada are in the top of oil exports to the USA and they aren't geopolitical adversaries.
However, I don't think that breakdown is necessary because if we cut consumption of gas by enough to halve our total imports that would cut the price of crude oil and gas again. With lower prices then Canadian tar sands oil and shale oil from Texas become too expensive to produce and the only exporters who would be able to sell to us would be the Saudis. We'd probably need to be close to a situation where domestic production would satisfy all of our needs before we stopped funding these other countries.
47.69 billion gallons of gas then.
Removing all roof racks to the tune of
100 million gallons/year is only a drop in the bucket at that point. Besides, that unfortunate trend is projected to increase to there being twice as many cars with roof racks as there are today in just 4 years.
I've been having difficulty figuring out miles driven by gasoline vehicles only which means an analysis can't be performed on miles driven, because the US miles driven stats include trucks and buses and other diesel vehicles, which number far fewer than gas cars but individually rack up way more miles. So from this point on the numbers start to get a little fuzzy.
But there is a number we can look at. The EPA estimates that the fuel economy for all 2014 model year cars that were produced (accounting for volume sold) was 24.3 mpg. This obviously doesn't account for older cars still on the road. Their 2004 number is 19.3mpg. Let's assume that the actual mpg of all gas vehicles on the road in 2015 was lower, let's assume it was 18mpg. There's a reason I chose 18 which will be illuminated shortly.
So we've got 140 billion gallons of gas/year, 47 billion coming from foreign countries and we're assuming each gallon is pushing a vehicle 16 miles. That means 2240 billion miles driven by gas vehicles. I chose 16mpg because the US DOT estimates 3.1 trillion miles driven total by ALL vehicles including class 8 trucks and buses and other diesel vehicles. If we set the estimate to 22 mpg average you'd be just under that number, so real-world mpg average of gas cars HAS to be considerably lower than 22mpg because we have diesel vehicles taking up a considerable portion of the mileage share.
The FHWA estimated that of highway travel light duty vehicles in 2013 (so excluding diesel trucks) was
21.6 mpg, but this is highway driving ONLY, no city driving, so again I'm going with the smaller assumed 18mpg number above.
So at 18 mpg, and 140 billion gallons of gas, we're hitting 2240 billion miles total. To kill foreign imports we want to reduce this by just under a third. This means 93 billion gallons of gas have to drive cars 2240 billion miles, or all the cars need to average 24 mpg between city and highway. Yearly miles driven is also going up, which is a problem, but mpg can probably increase faster than that.
Cars are 11 years old on average, and there's 253 million of them. That means about 6% of cars are replaced per year by new cars. Market fluctuations have a big impact on this, such as the 2008 recession. 2015 was a record year with over 17 million new cars sold.
The EPA was saying 2014 model year cars were hitting 24mpg combined, and it's reasonable to assume that number will keep going up. To make the US fleet average be 24 mpg however new cars are going to have to exceed that to offset both increases in miles driven/year and the older cars which are still on the road averaging worse than 24mpg.
The EPA's 2004 number was 5mpg less than 2014, so that's an average yearly increase of 0.5 mpg per model year. Maybe we can be generous and assume a 1mpg increase per model year which would put us at 30 mpg average in MY 2020 because of advances in technology and manufacturers willingness to incorporate aero features on all cars. The FHWA was also saying that cars, even as they're getting larger, are on average not increasing in weight. By 2019 (MY2020) we will probably have replaced a quarter of the cars that were on the road in 2015, so the 2019 number of gallons used, assuming we don't see a dramatic increase in miles driven, could hopefully be lower than 2015. But it might not be by much, and so in 2019 without dramatic changes in fuel economy, faster than 1mpg per model year, we're still going to be getting a significant portion of our oil from abroad.
Is there anything that can be done to get us to net 0 imports/exports? Maybe combined mpg of new cars will increase more quickly than 1mpg/my, especially as hybrids and electrics continue to increase in market share?
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