The average new car isn’t much more fuel-efficient than older ones. Still, to this day, the average vehicle has a range of between 20 and 30 miles per gallon, a stat which was very similar in the 1920s. How come with all the advances we’ve made in the last century is fuel efficiency the same?
In: Technology
This is a really complex question. Are we talking just four-door sedans? Because they have gotten more
Fuel efficient since 1920. But also, there are more variables than just fuel efficiency. For example, safety standards. A car built in 2021 and sold in the USA has to meet a tremendous number of safety standards. This means that fuel economy is sometimes sacrificed to meet these standards. Take a Honda Civic engine back to 1920 and slap it into a light crappy car and bam, there’s your efficiency gain. I mean you’ll be driving an unbalanced death trap, but you see what I mean.
A lot of modern cars are overbuilt compared to old ones: they have a large engine, more passenger seating, and usually some trunk space.
A prius, considered a fairly small modern car, weighs over 3000 pounds while the Model T (the stereotypical “old car” of the early 1900s) weighed up to 1500 pounds.
This means that a modern car can be twice the weight with the *same* fuel efficiency: definitely an improvement over the Model T!
If fuel efficiency hadn’t improved, you’d have horrible fuel efficiency in the range of 15mpg because vehicle weights have gone up significantly. Instead, fuel efficiency stayed the same (debatable, but ok) indicating that engines have absolutely improved
Most of the improvements in fuel efficiency have been reduced to nothing by things like increased speed, comfort and safety. A modern car is 3-4 times heavier then a 1920s car and have over ten times the power. However if you instead look at smaller slower cars there are several on the market which exceeds the 100 mpg mark.
While fuel efficiency doesn’t look like it’s gone up that much, it definitely has.
Also don’t forget that with the rise of electric cars, efficiency and emissions are on extreme ends, with MPGe almost an order of magnitude higher, while emissions are at 0. This doesn’t change the average fuel economy in gas cars, as they’re in a separate category of electric cars.
According to the EPA, since 2004, fuel economy is up 29%, power is up 16%, and emissions are down 23%. Compared to 1975, fuel economy has almost doubled while horsepower has increased over 75%.
When you only pay attention to fuel economy (and we’re not even talking about hybrids!), it’s easy to ignore things that also come into play, like innovations in safety, emissions, and power.
Just in the past 5 years, the average has increased almost 1 MPG while decreasing CO2 emissions, with some manufacturers like Kia increasing their MPG by almost 2.5
So it’s a few things. Fuel efficiency has been going up slowly but surely, but when you account for the power increase and emissions reductions, it’s a lot more substantial!
You can see all these stats [here](https://www.epa.gov/automotive-trends/highlights-automotive-trends-report)
Can you provide the information for this? It depends on the vehicles that are counted. Averaging a large SUV with a Prius says nothing about them as individual vehicles.
Here is a chart that shows improvement. https://www.greencarcongress.com/2019/09/20190930-sivak.html