Emissions

MaxB · August 24, 2018

In the latest edition of Which Car Guide, the IS (doesn't distinguish models) is their highest rated "large car" but is marked down (again) for "high emissions" and poor motorway fuel economy. I can't comment on the emissions, although it seems odd and contrary to most other testers I have checked, but I am very happy with motorway performance. What do you think?

I do have issues with the overly complex menu structure and the navigation system but that is another story!

rayaans · August 24, 2018

5 hours ago, MaxB said:

In the latest edition of Which Car Guide, the IS (doesn't distinguish models) is their highest rated "large car" but is marked down (again) for "high emissions" and poor motorway fuel economy. I can't comment on the emissions, although it seems odd and contrary to most other testers I have checked, but I am very happy with motorway performance. What do you think?

I do have issues with the overly complex menu structure and the navigation system but that is another story!

Dont subscribe to Which? car guide but they're taking the royal mick if they think the IS emissions are high

Motorway fuel economy is fine - you can easily get 50mpg on the motorway with a steady foot - again, talking out of their royal backsides

ColinBarber · August 24, 2018

2 hours ago, rayaans said:

Dont subscribe to Which? car guide but they're taking the royal mick if they think the IS emissions are high

They don't 'think', they know - the vehicle was tested with measuring equipment.

Quote

In our tests the hybrid IS was incredibly efficient around town with a very impressive tested economy figure of 97.4mpg. This is an enormous 40mpg more efficient than its closest rivals. However, economy drops drastically at motorway speeds, and it's barely more efficient than more powerful petrol-only rivals. Several diesel rivals consumed up to 20mpg less fuel at motorway speeds in our tests.

Alarmingly, we found the Lexus IS emits so much CO (carbon monoxide) in our tests that it would fail to meet any EU emissions limits set this century - despite it being a hybrid.

rayaans · August 24, 2018

59 minutes ago, ColinBarber said:

They don't 'think', they know - the vehicle was tested with measuring equipment.

Surely it depends on how they tested it. If it's being tested on the motorway it's going to be really high anyway. I'm sure other manufacturers are the same, just look at VW dieselgate. Other manufacturers were found to have high emissions too

NemesisUK · August 24, 2018

Hybrids are urban/town cars for economy, on the open road they are simple petrol cars....

NemesisUK · August 24, 2018

2 minutes ago, rayaans said:

Surely it depends on how they tested it. If it's being tested on the motorway it's going to be really high anyway. I'm sure other manufacturers are the same, just look at VW dieselgate. Other manufacturers were found to have high emissions too

Lets see the results obtained from other cars tested for motorway emissions

wharfhouse · August 24, 2018

1 hour ago, rayaans said:

Surely it depends on how they tested it. If it's being tested on the motorway it's going to be really high anyway. I'm sure other manufacturers are the same, just look at VW dieselgate. Other manufacturers were found to have high emissions too

At the end of the day, whether we like it or not, that's why we have to have standardised and controlled emissions tests so that although they don't fully reflect real world mpg figures they do at least compare apples to apples as much as possible - I take any other self appointed test results from any media publications with a pinch of salt as far too many variables involved.

ColinBarber · August 25, 2018

21 hours ago, rayaans said:

Surely it depends on how they tested it. If it's being tested on the motorway it's going to be really high anyway. I'm sure other manufacturers are the same, just look at VW dieselgate. Other manufacturers were found to have high emissions too

You should be able to read the following which talks about the testing methods used:

https://www.which.co.uk/reviews/new-and-used-cars/article/how-we-test/how-we-test-mpg-and-emissions

All CO reading will be high on the motorway but most Toyota engines perform poorly compared to other manufacturers. For example a 1 litre Aygo emits more than a Porsche 911 or BMW 4 series.

https://www.which.co.uk/reviews/new-and-used-cars/article/air-pollution-and-car-emissions/cars-that-produce-the-most-co

A lot of engines are clearly designed to perform well for emissions just within the narrow official testing criteria, they may not so as far as detecting a test and switching to a test defeating mode that isn't used in real life but effects are similar.

Vince Donald · August 26, 2018

Recent trip up to Scotland with 3 people in the car, boot completely full, averaged 49.8mpg and when on the motorway this was often creeping above 50mpg, and since CO2 must be related to consumption I'm skeptical.

Too many times I've seen articles based on Which reports yet lacking in detail as they want your cash, so I see them as a sensationalist organisation rather than a bastion of truth and righteousness, call me cynical if you like, I'm more likely to believe what I can see.

Vince

rayaans · August 26, 2018

19 hours ago, ColinBarber said:

You should be able to read the following which talks about the testing methods used:

https://www.which.co.uk/reviews/new-and-used-cars/article/how-we-test/how-we-test-mpg-and-emissions

All CO reading will be high on the motorway but most Toyota engines perform poorly compared to other manufacturers. For example a 1 litre Aygo emits more than a Porsche 911 or BMW 4 series.

https://www.which.co.uk/reviews/new-and-used-cars/article/air-pollution-and-car-emissions/cars-that-produce-the-most-co

A lot of engines are clearly designed to perform well for emissions just within the narrow official testing criteria, they may not so as far as detecting a test and switching to a test defeating mode that isn't used in real life but effects are similar.

That would make sense though as surely the smaller engines would be under a lot of load at higher speeds.

On the other hand, the CHR, Prius and Prius PHEV are all under the Euro 6 limit anyway.

Thackeray · August 26, 2018

It's obvious to any IS300h owner that the Which? magazine figures for fuel consumption are nonsense. They say you can get 97 mpg around town. If you spent a day driving around town (like many taxi drivers do with a Prius) I don't believe anyone would ever get anything like that. Maybe somewhere near the official 65 mpg. But 97 mpg is just clearly rubbish and should never have been published with the claim that this is fuel economy "you can really expect to achieve." I'm quoting what they used to say on their explanation page of consumption testing. I think they've now removed this claim but they're still quoting the nonsense mpg of 97 mpg around town.

The claim of 34 mpg on the motorway is equally dubious. A couple of days ago I drove a couple of hundred miles on French motorways at a steady 130 kph with four passengers and a boot full to bursting. The dashboard showed 48 mpg, which in my experience is fairly typical.

So if the Which? tests are so wrong on mpg, how can you trust their emissions figures? These are probably based in some way on fuel consumption but they won't spell out the details (I've asked them) except to say their tests are based on the NEDC official tests with some additional features.

They now have a misleading photograph of on-road testing equipment on the back of a car in their latest Car Guide. It's misleading because on-road testing wasn't used in the 2013 tests. But the figures they still quote for the IS300h seem to be based on their 2013 tests which didn't include any on road testing and only lasted about 20 minutes. Here's a video of the NEDC requirements simulated on the road rather than in a lab. It highlights what's wrong with the test.

But when you try to apply the same test to a hybrid for the sake of comparability, you get all sorts of distorted results. If the car's hybrid Battery is at 70% charge when it begins the NEDC urban cycle, a Lexus IS300h might travel two kilometres out of the total four kilometres test on its electric motor alone.

Then comes the "extra-urban" test section. But by this time the hybrid Battery needs charging. So some of the engine's power is diverted to charging the Battery rather than turning the wheels. If you measure this over just a few minutes, it will look as though you're getting very low mpg because not all the engine power is moving the car along the road. I would guess that this is why they got 97 mpg in the urban test but only 34 in their out of town testing when the Battery needed charging up again.

From memory, they originally gave the IS300h a test score of 82% and best buy status. When the emissions data became available later, they downgraded the car to 78%. Now they've upgraded it again to 80%. They give the impression that they don't really know what to do about the test results for hybrid cars. Maybe when they start using on-road testing they'll get more realistic results than the ones from 2013 which they seem to be still using. But unless they run the test for at least an hour or two, it's still going to be doubtful whether the results give a realistic picture of everyday driving.

NemesisUK · August 26, 2018

You can get phenomenal mpg figures depending on how one resets the trip computer.

The only mpg figure that means anytime that calculated from brim to brim fill ups. Taking in all one's driving routes and style.

MaxB · August 26, 2018

I too wrote to Which (when I was looking into buying an IS300h last year) in particular about their specific complaint relating to carbon monoxide, which isn't generally the most widely considered figure. I never received a reply either.

zippyone · August 27, 2018

Hello all,

this is always a contentious subject because there are so many variables, tyres, driving style, weather, petrol, the list goes on, all have been discussed in depth many times on the forum. Sometimes single things affect the performance of your car, other times it is a combination of things. Can i ask you, yes you the reader, "what tyres do you prefer, What petrol do you use and how do you drive ?" We all know these things affect the vehicles efficiency and performance.

I do not listen very much to the crud that the journos spew out, he who pays the piper etc, better to come to the forum where there are people who really know about cars hang out.

I am on my second 300H, MY13* and MY17**, the former standard, no toys, the latter Luxury, with all the toys.I use Spiitmonitor.DE and Fuelly. I find that i get better mpg on the motorway and B roads, than in town, I do not use cruise control. Motorway speed up to 80.77mph, other roads whatever the limit is + or - a bit.

Here are my results from Spiritmoniter, my board computer is around 4 to 5% shy and i brim fill each time. I do not know the formula for co2 emissions.

* 33,730m. 53.11mpg. CO2 124g/kg. £7.205 per 100km. 54 fillings. Now retired.

** 1,243m. 45.06mpg. Co2 146g/kg. £9.493 per 100km. 2 fillings.

These are my results, I am pleased with them. **has yet to settle in it is only a month old.

I do better than most, speed is not my forte now, i removed the go faster stripes years ago. These days it is more a case of trying to get where i am going in one piece.

I hope this little piece adds to the conversation.

best wishes.

Michael.

ColinBarber · August 27, 2018

On 8/26/2018 at 10:20 AM, Vince Donald said:

Recent trip up to Scotland with 3 people in the car, boot completely full, averaged 49.8mpg and when on the motorway this was often creeping above 50mpg, and since CO2 must be related to consumption I'm skeptical.

CO2 isn't in question, it is CO.

Vince Donald · August 28, 2018

19 hours ago, ColinBarber said:

CO2 isn't in question, it is CO.

A petrol engine will create mainly CO2 and a little CO, usually the CO is created when the engine is not running at its most efficient, now since hybrid systems are all about efficiency, they are designed to run the engines in as an efficient manner as possible - hence the atkinson cycle, in fact the atkinson cycle is supposed to create lower emissions of both NOx and CO.

Vince

Thackeray · August 28, 2018

On 8/24/2018 at 12:36 PM, MaxB said:

In the latest edition of Which Car Guide, the IS (doesn't distinguish models) is their highest rated "large car" but is marked down (again) for "high emissions" and poor motorway fuel economy. I can't comment on the emissions, although it seems odd and contrary to most other testers I have checked, but I am very happy with motorway performance. What do you think?

There was another thread about this in January but for anyone who didn't follow that discussion, it might be worth just recapping what the issue is.

Which? says in its review of the "IS hybrid" (ie 300h):

"It's a very good car, but we found the Lexus IS emits so much CO (carbon monoxide) in our tests, that it would fail to meet any EU emissions limits set this century."

So what does that mean? The carbon monoxide limits for Euro 4 (2005), Euro 5 (2009) and Euro 6 (2014) are all the same at 1 gram per kilometre (g/km). By saying the IS300h would not meet any of these standards it's saying that the IS300h emits more carbon monoxide than 1g/km.

It's not clear to me how they reached this conclusion as I haven't been able to find details of how their testing is conducted.

However, I did find a website for a specialist emissions testing company called Emissions Analytics. According to their website, their testing uses on-road emissions monitoring equipment in a three and a half hour run. By contrast, Which? until recently seems to have done a 20 minute lab test, though I haven't found any details to absolutely confirm this.

So what results did Emissions Analytics find? It classifies its results with a letter of the alphabet. The Lexus IS300h gets the top rating of A++, which corresponds to carbon monoxide emissions of between zero and 0.125 g/km. This compares with the Which? result of at least eight times as much carbon monoxide emitted, or possibly much more.

Emissions Analytics publishes its results in a table called EQUA Index. Click here for the webpage of results. Type Lexus into the search box to find the Lexus results.

So who can we believe has the more realistic test approach? A company which seems only to specialise in emissions testing, and claims: "We are the leading independent global testing and data specialist for real world emissions."? Or Britain's biggest consumer products testing organisation that assesses everything from washing machines to cars and computers?

I think there's a lot to be said for measuring actual emissions from the exhaust pipe in a real-world road test. If I remember rightly, this is how the Volkswagen scandal came about - they did well in the lab, but quite poorly when actual emissions were measured on the road. The IS300h seems to be the other way round - it didn't do well in the short Which? lab test but on a longer real-world test, measuring actual on-road emissions, it got a top rating.

ColinBarber · August 28, 2018

5 hours ago, Vince Donald said:

A petrol engine will create mainly CO2 and a little CO, usually the CO is created when the engine is not running at its most efficient, now since hybrid systems are all about efficiency, they are designed to run the engines in as an efficient manner as possible - hence the atkinson cycle, in fact the atkinson cycle is supposed to create lower emissions of both NOx and CO.

Vince

I'm not sure where the confusion is here. Which? removed their best buy status from the IS, and other Toyota/Lexus models, because CO emissions are way above supposed limits in their testing. Yes the amount of CO is much less than CO2, but there is a specific CO limit which isn't being met. They didn't have issue with CO2 or NOx emissions.

Serendip · August 31, 2018

On 8/28/2018 at 6:35 PM, Thackeray said:

There was another thread about this in January but for anyone who didn't follow that discussion, it might be worth just recapping what the issue is.

Which? says in its review of the "IS hybrid" (ie 300h):

"It's a very good car, but we found the Lexus IS emits so much CO (carbon monoxide) in our tests, that it would fail to meet any EU emissions limits set this century."

So what does that mean? The carbon monoxide limits for Euro 4 (2005), Euro 5 (2009) and Euro 6 (2014) are all the same at 1 gram per kilometre (g/km). By saying the IS300h would not meet any of these standards it's saying that the IS300h emits more carbon monoxide than 1g/km.

It's not clear to me how they reached this conclusion as I haven't been able to find details of how their testing is conducted.

However, I did find a website for a specialist emissions testing company called Emissions Analytics. According to their website, their testing uses on-road emissions monitoring equipment in a three and a half hour run. By contrast, Which? until recently seems to have done a 20 minute lab test, though I haven't found any details to absolutely confirm this.

So what results did Emissions Analytics find? It classifies its results with a letter of the alphabet. The Lexus IS300h gets the top rating of A++, which corresponds to carbon monoxide emissions of between zero and 0.125 g/km. This compares with the Which? result of at least eight times as much carbon monoxide emitted, or possibly much more.

Emissions Analytics publishes its results in a table called EQUA Index. Click here for the webpage of results. Type Lexus into the search box to find the Lexus results.

So who can we believe has the more realistic test approach? A company which seems only to specialise in emissions testing, and claims: "We are the leading independent global testing and data specialist for real world emissions."? Or Britain's biggest consumer products testing organisation that assesses everything from washing machines to cars and computers?

I think there's a lot to be said for measuring actual emissions from the exhaust pipe in a real-world road test. If I remember rightly, this is how the Volkswagen scandal came about - they did well in the lab, but quite poorly when actual emissions were measured on the road. The IS300h seems to be the other way round - it didn't do well in the short Which? lab test but on a longer real-world test, measuring actual on-road emissions, it got a top rating.

An interesting and informative post,

The online 2018 Which? report says:

'Best Buy award removed. It's a very good car, but we found the Lexus IS emits so much CO (carbon monoxide) in our tests, that it would fail to meet any EU emissions limits set this century. As such, we cannot possibly recommend it.'

'Should I buy it? No, it's a very good car under some driving conditions, but the concerns around harmful emissions mean we can't possibly recommend it.'

Having read Thackeray's post above, I found the Emission Analytics report and contacted Which? for their comments.

They told me that - The engine test is the 300h F Sport Automatic, which we evaluated in 2013 soon after it came out, a Euro 5 engine. When we test the latest Euro 6 engine, we will update the review with what we find; hopefully the later engines will be cleaner.

wharfhouse · August 31, 2018

1 hour ago, Serendip said:

An interesting and informative post,

The online 2018 Which? report says:

'Best Buy award removed. It's a very good car, but we found the Lexus IS emits so much CO (carbon monoxide) in our tests, that it would fail to meet any EU emissions limits set this century. As such, we cannot possibly recommend it.'

'Should I buy it? No, it's a very good car under some driving conditions, but the concerns around harmful emissions mean we can't possibly recommend it.'

Having read Thackeray's post above, I found the Emission Analytics report and contacted Which? for their comments.

They told me that - The engine test is the 300h F Sport Automatic, which we evaluated in 2013 soon after it came out, a Euro 5 engine. When we test the latest Euro 6 engine, we will update the review with what we find; hopefully the later engines will be cleaner.

The IS 300h was announced as Euro 6 compliant in April 2015... That means Which has left these comments on the car report for well over 3 years - they should at least clarify - I'm surprised Lexus didn't approach them given what they have said. Then again I don't subscribe to Which and don't know anyone else who does...!