Unveiling True Fuel Economy: Why GPHM Beats MPG in Efficiency Insights

by AutoExpert   |  24 May, 2024

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Fuel economy is one of the most important criteria when choosing a new car. You may wanna spend a fortune on the car but spending a fortune on gas is not the greatest thing. That's why MPG - Miles per Gallon - is THE figure we all pop our eyes at fist thing. But is it really all that straightforward?

Turns out, MPG might not be the whole story.  Vox just dropped an article arguing we should be looking at gallons used per 100 miles (GPHM) instead.  Think about it like this: imagine you have two cars. One gets a sad 10 MPG, the other a slightly-less-sad 15 MPG. Not great, right?

Fuel Economy

Here's the shocker: Swapping the 10 MPG car for the 15 MPG one saves you a whopping 3.3 gallons per 100 miles! That's way more than the difference between a 25 MPG car and a 50 MPG car (which only saves 2 gallons).  See where the MPG illusion comes in? We tend to overestimate the benefit of small improvements on already-guzzling cars.

Now, don't get me wrong, a 50 MPG car will definitely cost less to fill up than a 25 MPG one. But for setting policies and encouraging car companies to actually improve fuel efficiency, MPG might be missing the mark.

Fuel Economy

Here's why:

Trucks and SUVs get a free pass: The current system (based on MPG) has different standards for cars and trucks, even though trucks are all the rage these days. This lets them off the hook, even though they guzzle gas like nobody's business.

Focus on the wrong improvements: Car companies might just focus on making already-efficient cars even more efficient, instead of tackling the gas-guzzling beasts.

Fuel Economy

So, what's the alternative?  GPHM!  The Europeans are already using something similar to GPHM which measures the number of litres consumed per 100 km. While USA would need some time to get used to it, this system is way more transparent on the actual car fuel consumption.

Fuel Economy

The good news? GPHM is already listed on new car stickers, along with an estimated annual fuel cost. We just need to shift our focus to this metric to truly understand how much gas a car will use and encourage everyone to ditch the gas guzzlers!

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