While most hybrids are said to use one to two litres of fuel per 100km, a study claims they need six litres on average
Plug-in hybrid electric cars (PHEVs) use much more fuel on the road than officially stated by their manufacturers, a large-scale analysis of about a million vehicles of this type has shown.
The Fraunhofer Institute carried out what is thought to be the most comprehensive study of its kind to date, using the data transmitted wirelessly by PHEVs from a variety of manufacturers while they were on the road.
. . .
According to the study, the vehicles require on average six litres per 100km, or about 300%, more fuel to run than previously cited.
The scientists of the Fraunhofer Institute found that the main reason for the higher-than-stated fuel usage was due precisely to the fact that the PHEVs use two different modes, the electric engine and the combustion engine, switching between both. Until now it has been claimed by manufacturers that the vehicles used only a little or almost no fuel when in the electric mode. The studies showed that this was not in fact the case.
People in this comment section are obtuse as fuck, I don’t know if willingly or not.
Thanks for posting the study, they’re completely missing the point, and it was an enlightening revelation to me
My 2003 petrol car gets 6 litres per 100km. Even if the PHEVs are running like a normal hybrid 100% of the time, that economy is trash.
My 2006 diesel swallows 5.1L/100km, and it fits 7 people inside. New cars are mastodontic for no fucking reason
The article is horribly unclear: it seems to say that PHEVs are no good, but “the main reason for the higher-than-stated fuel usage was …that the PHEVs use two different modes, the electric engine and the combustion engine”. Well, so do non-plugin hybrids. I doubt they’re saying that plug-in hybrids are worse than non-plugin, but you might guess that from the title.
The article states that Porsche PHEVs used 7 liters per 100 miles (33.6mpg), but Kia/Toyota/Ford/Renault used “85% less” (1.05L/100k or 223mpg… I think we can agree this is not a serious number).
Porsche mentioned “different usage patterns”. I can buy that a typical Prius owner is plugging-in every night, filling low-rolling-resistance tires to 54psi and driving like grandma, and a typical Porsche owner… isn’t. If you want apples-to-apples, then compare a gas Corolla vs a Prius vs a Plug-in Prius, where the cars are from the same city/suburb, and similar owners (e.g.: no ubers, no regional sales reps).
This “study” is evaluating real-world use of one class of vehicles, and not other vehicle types; then using the dismal ways some people drive to imply that this particular class of vehicles is the problem.
I think the point is that PHEVs do not achieve the real world emissions promised by the manufacturers, which would call into doubt reliance on them to save the climate as well as tax reliefs. Particularly, company cars are historically subsidized too much, and they get even more subsidies if they are hybrids, only to then never charge them.
So I own one of these vehicles and I was thinking there’s no way this can be because I can see my fuel consumption and it is very low. But according to the article it varies greatly by model, and mine was mentioned as being on the low end.
For me at least, I can hear when the engine turns on and it does not do so until the battery range is used up, so there should be no fuel usage during such trips. It seems quite strange that some vehicles would work otherwise.
Until now it has been claimed by manufacturers that the vehicles used only a little or almost no fuel when in the electric mode.
I have a PHEV and the gas engine shuts off completely when in electric mode. I don’t see how it could be using gas when it’s not running. Are they confusing the hybrid mode with electric mode?
It depends, some use the engine to charge the battery (e.g. the Honda Civic).
The civic isn’t a PHEV
You’re right, my mistake. But for example, the BMW 530e G60 does have a button to charge the battery from the engine, and it is a PHEV. So it does exist.
Misleading article. Someone reading this may think that a PHEV will have higher fuel consumption than claimed. When it reality it should be clarified that fuel efficiency is based on roughly 75% electric drive share.
I see the point where they should adjust that down based on real.world usage.
But… if you are expected to drive 75% electric based on battery range and your usage, you will hit the manufacturers claims, give or take
How is it misleading?
Manufacturers make claims about fuel consumption. Based on studying real-world data, fuel consumption is significantly worse than claimed. The study authors say that internal combustion engines are active much more frequently than claimed. They propose that manufacturers and regulators use real-world data because it’s more accurate. Is that such a bad idea?
Because the stupidity of consumers is hard to under estimate by engineers.
The problem is not the car designs, it’s that idiots don’t plug in, plug in hybrids, they run them only on gas. They should be charging them overnight. Regardless, they still use significantly less fuel than just ICE designs.
Its misleading because they’re pushing this like it’s Dieselgate when in reality it’s just that the “MPGe” rating (and metric equivalent) is just a dumb fucking estimation. Porsche states that you get 29 miles electric range at most and then everything else is 22-29 MPG. That’s how PHEVs should be quantified.
Imagine a Porsche owner driving 20 miles to work, charging, and then driving 20 miles back home. How much fuel was used?
Now imagine another Porsche owner driving the same 40 miles but in one trip. How much fuel was used?
How about a third Porsche owner driving 20 miles but flooring it after every stop light in cold weather, not charging, and then driving 20 miles back home. How much fuel there?
These would all give wildly different results which is why any combined estimation will be wrong regardless of the method. Same goes for ICE vehicles but to a lesser extent since they’re always burning fuel. Combined city/highway is going to be different if that ratio is 90/10 versus 10/90. Its going to be different based on weather, driving style, number of passengers, etc. The whole point of this is to simply compare vehicle efficiencies in an apples to apples way not perfectly predict what you’ll actually experience driving the car.
There’s no scandal here just sensationalism.
Why are people so bizarrely defensive about this?
This isn’t sensationalism. It’s a scientific study of actual real-world fuel use based on data from thousands of vehicles (at least ten thousand, I assume, based on earlier studies). If, as the study author says, internal combustion engines are being used more frequently than estimated, should it not be addressed? Should we not be aiming for higher efficiency in these vehicles? If tests aren’t accurately predicting usage, should we not develop more accurate tests?
On the assumption phevs have the combustion engine off unless they are in hybrid or performance mode:
I think it’s decisive because the article’s focus is fuel consumption but fuel consumption in phevs is actually just a proxy for driver behaviour. (Once you factor out differences between models)
So while the study does show that phevs technically have worse fuel economy in real world usage, it doesn’t show they use more fuel in either electric mode or in hybrid mode than previously believed.
The conclusion is useful for understanding the overall impact of phevs on petroleum consumption, air quality and global warming, but it’s misleading when evaluating what kind of car you should buy.
Since you know how you drive, learning new information about average driver behaviour doesn’t factor into your decision on what kind of car you buy.
The environmentally conscious answer is still no car if possible, electric if you need a car but most journeys fall within the range limit and phev if you need a car for frequent long range usage.
Tldr; it’s contentious because the article reports information useful for policy decisions to a general public who are making individual consumer decisions where the information is misleading.
Its not defensiveness it’s just recognizing the issue for what it really is. You can change the estimation calculation all you want, but it will always be wrong because the variables being used don’t blend together well. You can make gas engines that get 100MPG or even 1000MPG but it won’t make for an accurate estimation when averaged out with ∞MPG or 0GPM.
internal combustion engines are being used more frequently than estimated
That’s a problem with the estimation not with the manufacturers. The manufacturers tell you exactly what the electric range is and also what the ICE fuel economy is. It’s trivial to apply these values to your driving habits to get an estimation for your use case.
should it not be addressed? Should we not be aiming for higher efficiency in these vehicles?
Here you’re conflating two separate issues and highlighting exactly why people are calling this misleading. You can change the calculation all you want but that isn’t changing the efficiency of these vehicles and this study doesn’t demonstrate that these vehicles are inefficient. All it shows is “your MPGe or l/100km is greatly effected by how often you stay on electric power” and that factor is solely dependent on the driver and ranges from near zero to infinity.
If tests aren’t accurately predicting usage, should we not develop more accurate tests?
It doesn’t get more accurate. We should just scrap the combined “MPGe” (and EU equivalent) and stick with “electric range” and “MPG”. Both of those can be fairly accurately predicted as separate values. How they combine is entirely up to the individual.
If tests aren’t accurately predicting usage, should we not develop more accurate tests?
It doesn’t get more accurate. We should just scrap the combined “MPGe” (and EU equivalent) and stick with “electric range” and “MPG”. Both of those can be fairly accurately predicted as separate values. How they combine is entirely up to the individual.
I agree with everything you’re saying, but this part. As you stated before, those are intended to allow for an apples to apples comparison and make it easier for the consumer to judge a car’s funel economy, without having to do their own math (which - lets face it - most people suck at).
If the underlying usage pattern doesn’t reflect a typical average use, that’s an issue, that can be adressed. And when studies show that they don’t why not take that as a call to improve upon the methodolooy?
There’s always going to be the caveat that one’s one usage pattern might deviate greatly from the standard, and absolutely it’s a must, that the individual values are indicated, so people CAN do their own math. But having a standard combined measure is still a useful tool.
Addendum. I have to admit to really only having read the article just now.
The scientists have called on EU regulators to adjust their measurements to fit the real-world findings, urging stricter controls as to how fuel consumption of plug-in hybrids is measured. According to the findings, the CO2 limits a car manufacturer’s fleet of vehicles is allowed to emit on average needs to be urgently adjusted.
Contacted by SWR, the EU Commission, which is responsible for CO2 limits, declined to comment on the findings.
The German Association of the Automotive Industry said it believed that existing measures to determine fuel consumption and CO2 emissions were reliable.
This is the real underlying issue here. It’s the EUs regulation on CO2 emissions reduction, that car manufacturers are abusing here. They are designing their car in such a way, that they look good on paper and can pass the requirements of the regulation, while their real-world emissions are much higher. (And in that regard, it’s not too unlike Dieselgate. Minus the intentional technical manipulation ofc.)
While your claim, that it’s the individuals responsibilty how they use their car is obviously true for an individual car’s fuel consumption, that realization is also utterly useless as a basis for effective policy. There needs to be a standard, and that standard better reflect an empirical assessement of reality.
This issue isn’t really that the estimate is wrong, it’s that it’s wrong by an enormous amount – and one that’s been increasing every year. I don’t think that the study is trying to say that these vehicles are inefficient as some kind of absolute judgment, but that they’re less efficient than estimated (although there are big differences based on vehicle make and model).
I don’t think the problem really lies with manufacturers, it’s that the current tests aren’t accurate enough to predict real-world usage closely enough. Although, driver input is mediated by computer systems and if on-board systems are being too aggressive in switching over to ICE, I suppose that’s a manufacturers problem.
Really, they’ve been doing these very large studies for a long time. The sample size is large enough to capture the full diversity of driving styles and it cannot be a few outliers skewing results. Since 2012, the disparity between estimated and observed fuel usage has grown every year. Why? Why is it changing and why is it always changing in the same direction?
It getting worse over time I would think is partially a function of customer mix changing.
You start with early adopters who are more eco conscious and then now entering mainstream, and also people choosing plug-ins for performance purposes.
plug in hybrids are impossible to properly quantity fuel usage. because unlike normal cars where you estimate highway/urban use, now you have to also consider EV/ICE use.
if you rarely use the engine, then your fuel usage is negligible. while if you mostly drive it like s hybrid and never charge it, it’ll be just as good as a comparable hybrid.
Statistics exist, taking a sample of thousands of PHEV drivers and examining fuel consumption is exactly what we can do to quantify fuel usage. And the reality is that, on average, they use up more fuel than my 2006 diesel I got for 2000€. For the vast majority of people, PHEV are just a scam
Do you know why diesels are no longer made? It’s not just about fuel consumption. They are filthy oil burners sold illegally on faked data and you are wearing it like a badge of honor. Read.
acreage is meant to give you an estimate of how much is it going to cost you, if it is off by 20% based on you doing now highway than the average, that’s fine.
but if it’s off by 100%? that’s useless.
also, averages only works if the data falls under a normal distribution. if you have people charging their cars at night, and others who don’t, that is not a normal distribution amd averages are useless
Averages don’t only work if data falls under a normal distribution. I can have two very non-Gaussian distributions for fuel usage of two vehicle types but one of them has much lower fuel consumption than the other, I can vouch for the lower one using the average alone.
It’s misleading because it is reporting a very generalized average fuel consumption (actual usage) of all PHEVs while manufacturer claims are based on individual vehicle potential.
Manufacturers cannot control how people use their cars, they can only assure that the cars operate the way they claim when used the way they suggest.
But isn’t that like Apple saying “you’re holding it wrong”?
I don’t think it’s being portrayed as a manufacturer conspiracy. When Porsche says their tests are “based on the legally prescribed EU measurement procedures,” I’m sure they’re not lying. But these data say pretty clearly that those tests don’t predict observed reality. If they don’t, what good are they really? Shouldn’t we use testing that better reflect observed fuel usage?
No. It’s like blaming ladder companies because people fall off ladders while drunk.
If a person designs to bash in their face with a hammer, government should not ban hammers.
Americans love to sit idling their V8 trucks.
The way I read it is:
- if you never plug-in overnight, and the vehicle is big, and you drive aggressively, you get 34mpg (believable)
- but if you plug-in a small car every night, and you get 75% of your miles electric, and you drive like a grandma, then you get 223mpg (believable)
Sadly, it sounds like Porsche drivers may fall into the first category and Toyota drivers in the second. And there are enough Porches to skew the MPG of the whole PHEV class.
(it’s also possible that Porsche/VW/Audi just make PHEVs that score well on gov’t tests but poorly in the real world, though I’d lean towards the drivers. But the article title really implies that all PHEVs get shockingly bad mileage)
I think it’s more like Apple saying you get 24 hours of battery life on an iPhone, but in reality, if you use it frequently or play games, the battery underperforms to the stated life. If these vehicles are driven aggressively or not recharged at mfg expected intervals, like fleet utilization, that would skew the general mpg for the population. I’m not saying that’s what happening, but it’s a possible explanation.
I guess it’s just that 300% on average seems like a lot, y’know? Like, if the average iPhone user was getting just 8 hours of an advertised 24, people would be pretty pissed. They’d probably ask for testing that better reflects real-world usage ;)
But if 50% of iPhone users are professional mobile gamers, their utilization is an outlier skewing the sample. I’d like to see the population in the sample for this study. For the average PHEV driver, they probably get close to the mfg estimate when driven as expected but the generalized data encompasses non standard users.
ICE vehicle manufacturers don’t give MPG estimates based on burning out at every stop light, driving with various octane fuels, or many other factors that can effect fuel economy. They give estimates based on a certain usage. I have a Subaru WRX and average 2-3 more mpg than mfg estimates on hwy usage. That difference is in my favor, but it still shows that estimates are just estimates based on a baseline use.
If Apple were dismissing half their users as outliers, I still think people would be pretty pissed…
For the average PHEV driver, they probably get close to the mfg estimate when driven as expected but the generalized data encompasses non standard users.
Based on what though? Is this just an assumption?
I’d like to see the population in the sample for this study.
Unfortunately (and annoyingly), the Guardian doesn’t link to the study. I took a quick look and found a similar study from 2022 (PDF but nothing recent. Their conclusions are similar and they do differentiate between private and fleet vehicles.
Outrage seems to be inversely proportional to experienced convenience, not necessarily performance disparity.
Car manufacturers have always overstated mileage ratings because their tests are done in very controlled environs under ideal conditions.
They cannot control how you use their vehicle, but they can baseline it. That’s what those ratings have always reflected, and why. “Here is the way this car performs under ideal circumstances. YMMV”
Because the outcome of that “statistic” highlights phev as a bad purchase. It took far more scandal and coverup exposing to reveal more egregious figures from ice cars, for example the Volkswagen testing thing.
If fuel economy can be tempered with real-world use effects for ice cars, the bigger picture is warranted for this study as well.
Manufacturers typically market the vehicles as energy efficient.
Because they are more energy efficient…
Until now it has been claimed by manufacturers that the vehicles used only a little or almost no fuel when in the electric mode. The studies showed that this was not in fact the case.
Because when in pure electric mode they do use little or no fuel (different cars have different architectures but this is generally so)
But, yes there is a good point buried in there. Europe needs to update rules on efficiency claims. l/100km in gas mode, and electric range gets you pretty far.
Europe needs to update rules on efficiency claims. l/100km in gas mode, and electric range gets you pretty far.
I see both of those listed pretty much everywhere when it comes to plug in hybrids.
I met someone who had been given a PHEV company car. They had been driving it for 6 months, and I was the first person who informed them that their car could be plugged in to charge. They thought it just charged itself while driving.
I doubt this is an isolated incident.
Many companies and councils are trying to look more green by making the switch to EV, but don’t want the “risk” of an actual EV. I believe they are the main customers for PHEVs, and they are also the least likely to recharge them.
I’ve even heard of people deliberately refueling and not recharging because they have a company car for fuel, but would have to pay for electricity themselves.
Sounds like the companies should also issue their PHEV’d employees a portable gas-powered generator they can fill up when they fill the car to then use at night to charge the car’s batteries. Bureaucratically the math is flawless.
While most hybrids are said to use one to two litres of fuel per 100km, a study claims they need six litres on average
I can say from personal experience that my Chevy Volt gets around 40-60mpg when it kicks over to gas. That said, it rarely does, because my daily commute comfortably inside the battery’s range.
Until now it has been claimed by manufacturers that the vehicles used only a little or almost no fuel when in the electric mode. The studies showed that this was not in fact the case.
Again, I’ve got a tank of fuel from… several months ago? Barely 7 gallons and it hasn’t run out. Like, I almost never visit the gas station anymore. So, idk. Maybe the Volt was just built better.
Based on my interpretation of the article the Porsche plug in was so bad that it skewed the study, it used 85% more fuel than all of the other cars in the study. But it doesn’t surprise me, it’s not the first time Porsche (Volkswagen) wasn’t very trustworthy with their fuel stats in recent years. Something was that the less expensive the car, the better it was on fuel economy, seems logical once you think about it. The more sensible the car the more likely that buyer is to be concerned with those types of stats.
Something was that the less expensive the car, the better it was on fuel economy, seems logical once you think about it.
Nobody (expecting to win) is street racing a Volt or a Prius, to be sure.
So there’s little incentive to cheat emissions standards in order to juice performance.
There’s no way it would win a race, but I have to say, I have the latest Prius Prime and it’s actually pretty damn fast, especially for a Prius. They really shook off the underpowered rep with this latest batch.
This mirrors my experience with my 2017 Prius Prime. On the rare occasion when I activate gas mode (e.g., for long trips) it gets 50 mpg no problem. Otherwise it’s an electric car and the gas engine is completely shut down.
During COVID lockdowns, we were driving a lot less. We got a warning message that we needed to burn at least 5 gallons of gas each year to keep it from going stale. So we drove it exclusively in gas mode for a while, then went right back to not caring about gas prices at all.
The Prius PHEV basically turns into a regular Prius once the battery is empty because Toyota designed it for low consumption. Others like Volkswagen just needed PHEVs for tax reasons, so the actual consumption does not matter to them.
You’re from the US.The US fixed the bullshit method of claimed fuel mileage about two decades ago. This article is all about the EU. Their official fuel efficiency ratings still have room for bullshit.
It’s not even that, it’s the abomination of combining electric and gas “efficiency” into a single unit. That number is always going to be trash when one of those variables represents zero fuel usage and other represents pure fuel usage.
Doesn’t gas go bad eventually? Could that be a problem if you end up needing the ICE to turn on?
I used to have a motorbike that I hardly ever used and it was so unreliable because of this. I ended up having to get rid of it in the end because it just wasn’t worth the effort for the amount of time that I used it.
they actually thought of that when designing the volt. the tank is pressurised to stop evaporation (which causes the concentration of additives to change so they fall out of solution), and the engine runs for a minute or so every month (or if you haven’t started it in a while) to make sure there’s no bad gas in the lines.
Wow, awesome tech
I have a different model, but it more or less vacuum seals the gas tank to mitigate that - it is still wouldn’t last forever, but without air to react with the aging process is significantly slowed down.
Fleet vehicles are skewing numbers too. They often don’t get plugged in regularly and use the gas engine far more.
Yes From the data tables in the research paper, company cars were seeing roughly 25% electric drive share, private 50% - quick back of the napkin math.
I got a Chevy Volt last year and I went from spending $350 per month on gas to spending around $20 per month (up to almost $30 when it was so cold last month).
Just curious, did you notice anything in your electric bill?
No, you’re actually spending $900 per month on fuel but don’t realize it because the manufacturers lied about it.
Shit… and here I’ve just been blaming tariffs and inflation for my money disappearing!
Damn those manufacturers.
No, this is poorly framed information. They don’t “require” on average 300% more fuel to run. The drivers choose to charge their cars 300% less often than manufactures suggest. This is skewed by rental and fleet cars whose users never charge the car, and by owners who treat their car as a normal hybrid instead of charging it. I was once given a plug-in hybrid van as a rental car but never told it was a PHEV. I didn’t figure it out until the next morning when I was walking up to it and saw the charging cover. My hotel didn’t have a charger, so I couldn’t really do anything about it; but if I were a normal person and not someone who has owned multiple EVs then I wouldn’t have even thought to charge it.
Also, the Porsche one makes total sense. The car is going to burn through battery charge and then hit the gas engine faster when, as expected, Porsche drivers drive them like a Porsche.
Also, the Porsche one makes total sense. The car is going to burn through battery charge and then hit the gas engine faster when, as expected, Porsche drivers drive them like a Porsche.
It really is insane. They only rate the range for 29 miles and then get 22-29MPG and make something like 540HP. I wonder (but didn’t bother looking up) if their design allows the electric motor to boost the power of the gas engine rather than boost fuel economy in which case you’re talking about smiles per gallon not miles per gallon.
Not to throw shade, but why the fuck would you want to maintain 2 entirely separate power trains. It’s a recipe for extra maintenance costs in my view.
BEV4ME.
It’s not two entirely separate powertrains though, it’s usually just an engine paired to a hybrid motor/transmission combo and they’ve been on the roads for decades, so it’s easy to see what their typical repair costs are.
I’m not sure about how ALL plug-in hybrids work, but I know that most models a single, electric, power train. The gas aspect is a generator that can power the electric motor and offload it’s excess power into the battery. That way when the generator is needed it can almost always be at it’s optimal power setting.
With the Toyota kind, it’s both, but they have a special transmission/eCVT for it, rather than just bolting a motor to the driveshaft.
The motor’s also responsible for the engine gearing in that case.
The PHEV just uses a beefier motor, so it doesn’t need the engine to move the vehicle.
