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Discussion Starter · #1 ·
Cars with smaller engines may guzzle more fuel than bigger cars, study finds

Researchers tested more than 500 cars of varying models on British roads

Miles per gallon fuel consumption widely differs from manufacturers' claims

Emission Analytics said it was because cars are tested at slower speeds

Motorists who think smaller cars guzzle less fuel may want to think again after research revealed that bigger vehicles may actually be cheaper to run.

While drivers are often led to believe that smaller cars can travel more miles per gallon (mpg), research by Emission Analytics found that they often use up more fuel because they generally have to work harder to accelerate.

As part of the research, the data company - which studies fuel consumption and emissions figures for road vehicles – tested more than 500 cars.


The study tested fuel economy in 500 vehicles and compared engine size to miles per gallon. It found that small cars (with an engine of one litre or under) had the biggest variance in advertised mpg figures and actual mpg


Researchers chose a range of different models, and a mix of both petrol and diesel vehicles, and drove them for three hours on British roads while studying the amount of fuel they used.

They found that all of the cars tested travelled on average 18 per cent fewer miles per gallon than stated in manufacturers' specifications. The data analysts said this was because the vehicles accelerated more and travelled at higher speeds on the road than in official testing regimes.

The greatest variance between manufacturers' claims and actual performance was found in vehicles which had an engine of one litre or under.

They achieved 36 per cent less than expected in terms of fuel economy, after fuel consumption measured at 38.6mpg – differing significantly from its advertised 60.3mpg.
Cars with an engine size of between one and two litres performed at 21 per cent less in fuel economy while engine sizes of between two and three at 15 per cent less.
In comparison, vehicles with an engine of five litres or more had just a one per cent variance between its actual mpg and its advertised mpg.

An Emission Analytics spokesman said: 'For maximum fuel economy you should look for a one to three litre engine, as these will return around 45-46mpg.
'And, to avoid being too disappointed with the result, pick a two to three litre vehicle as it will be only 15 per cent worse than you were told you could achieve.'


Nick Molden, Emission Analytics' founder, said the remarkable difference between advertised miles per gallon figures and the actual figures was down to the way vehicles are tested.

He said official testing regimes involve lower rates of acceleration and lower speeds than those demonstrated by car owners.

He told The Telegraph: 'The problem at the moment is how official tests are leading people to outcomes that are not helping the environment.

'Where people buy engines that are below one litre, you are getting worse fuel economy, therefore you are getting worse CO2 and you may also be getting more nitrogen dioxide, and that's not what is intended by the regulations.'

Professor Stephen Glaister, director of the RAC Foundation, said: 'These astonishing figures only fuel the debate on the worth of official mpg data.

'Well over two million new cars will be sold in the UK this year, with small vehicles topping the sales chart.

'But how many drivers will actually get what they think they have paid for? The answer, in terms of fuel efficiency, must be not many.'


Read more: LINK

Whats the best highway cruiser? a gas guzzling high revving noisy underpowered 1.0L, or a big quiet engine thats purring just ticking over a low revs, a tough choice LOL the penny is starting to drop at long last.
 
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Discussion Starter · #3 ·
How you drive is the single most important factor on how close you get to projected mpg.
And more important than mpg is safety, with larger more substantial vehicles being safer than small cars.
Larry Leadfoot is no good at MPG or safety in any type of car, Tommy Tortoise can be just as dangerous with a mile long tailback keeping a whole line of traffic stuck behind following in lower gears wasting fuel frustrating the hell out of everybody making them have to do maybe risky overtaking manoeuvres that they would not normally have had to do if Tommy had kept up to speed..
 
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also the type of driving you do IE mid speed hi way commuting on (mostly) clear roads then yes a LARGE sedan will have better aero AND gearing to keep the engine "idling" at speed
BUT "heavy" CITY driving with VERY low speeds and high levels of crawling then the smaller cars would do better as the speeding up/slowing down is mostly a weight issue + LOW power demands = in efficient LARGE/Hi power engine operation
 

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This is such an old argument.

I remember in the 60s when Olds introduced the Cutlass or F-85 or whatever they were calling their intermediate then, with the Tango Charlie aka Turnpike Cruiser package. Theory being that a big engine loafing, especially on the highway, will make as good as or better MPG than a smaller engine working harder.

TC had a 400 (2bbl or Quadrajet, I forget) with loafer rear gear, probably 2.41 or 2.29 such as Poncho used in the late 60s. My 1967 Catalina had a 2.41 with a 1:1 3rd gear ratio, in 1968 they had a 2.29.

edit: Checked. 2bbl. 2.56.
http://www.oldsmobility.com/old/carlife_apr67.htm

http://www.curbsideclassic.com/blog...ubic-inch-1967-olds-cutlass-turnpike-cruiser/

So does a 400 with a loafer gear do better than a 330 with shorter gears? Depends.

How you drive is the single most important factor on how close you get to projected mpg.
And more important than mpg is safety, with larger more substantial vehicles being safer than small cars.
And the vehicle is the second most important factor.

Check my Fuelly numbers.

My 2800 lb. 2013 Soul Base 1.6 6A [27.8 MPG] (top gear 25 MPH/1000 RPM) which BTW was pulling a brick with Cd of something like .42, did only slightly better (12%~), overall, than my 2013 Charger 3.6 8A [25 MPG] (top gear 43 MPH/1000 RPM) pushing a 4100 lb. car with Cd of about .30.

Driving style the same. Obviously the Soul needed more loud pedal encouragement than the Charger to build up to cruising speed.

Interestingly, the 3600 lb. 200 3.6 6A [23.5 MPG] with pretty tall gears, something like 37 MPH/1000 RPM in top gear, got significantly worse MPG than the Charger, considering 500 lb. lower weight.
But its aero was considerably blockier, I'd guess on the order of .34-.36. And I'm sure the 6A trans was nowhere near as efficient as the ZF 8A.
 

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This kind of real world result also becomes interesting in terms of emissions.

And all kinds of taxes.


And then emissions again - perhaps - if also measured in the real world simultaneously.

Which possibly brings you back to taxes - yet again as well.


Finally..... the safety loss aspect deserves consideration ......


What a cluster -

However just remember -

close enough for Government work
 
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Discussion Starter · #9 ·
This kind of real world result also becomes interesting in terms of emissions.

And all kinds of taxes.


And then emissions again - perhaps - if also measured in the real world simultaneously.

Which possibly brings you back to taxes - yet again as well.


Finally..... the safety loss aspect deserves consideration ......


What a cluster -

However just remember -

close enough for Government work
LOL thats right big brother in places like the EU is gonna rig skew EU government C02 testing in favour of bringing out higher C02 numbers in the tests so they milk collect more tax revenue out of the EU motorists wallet. It called legalised stealing.
 

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Here is something related -



ICCT: gap between official and real-world fuel economy figures in Europe reaches ~38%; call to implement WLTP ASAP

28 September 2014

The gap between official and real-world fuel-economy figures in Europe has risen to about 38%, according to a new report published by the International Council on Clean Transportation (ICCT). Ten years ago the discrepancy between these real-world and sales-brochure values was at 10%. The new report—“From Laboratory to Road: 2014 Update”—updates ICCT’s original 2013 report on the growing discrepancy. (Earlier post.) -






The data show that for private cars, the difference between on-road and official CO2 values rose from around 8% in 2001 to 31% in 2013. For company cars, the gap is even greater: 45% in 2013. -



- One new feature in the 2014 report is an examination of vehicle models. When looking at individual vehicle models, the ICCT researchers found that when a new vehicle model generation is introduced, the gap suddenly increases from one year to another Looking at 26 of the top-selling models in the EU, they found that for vehicle model changes before 2009, each time a new generation came on the market, the average gap increased from 12% to 17% of the official CO2 value from one year to the next.

For more recent model changes—after the EU CO2 regulation for new cars was introduced in 2009—they found that the typical increase in the gap from one generation to the next jumped even more, from 18% to 29%. -



- The authors noted that “it is reasonable to assume that driving behavior has not changed appreciably over the past years.” Instead, they suggested that the observed increase of the gap is most likely due to a combination of:

Increasing application of fuel-saving technologies that show a higher benefit in type-approval tests than under real-world driving conditions (for example, stop- start technology).

Increasing exploitation of “flexibilities” (test tolerances and insufficiently defined aspects of the test procedure) in the type-approval procedure (for example, during coast-down testing).

External factors changing over time (for example, increased use of air conditioning).

Manufacturers measure vehicle fuel consumption in a controlled laboratory environment, using a test procedure called the New European Driving Cycle (NEDC). This procedure was developed in the 1980s and was not originally intended to be used for fuel consumption testing but air pollutants. A new and more appropriate test procedure, the Worldwide Harmonized Light Vehicles Test Procedure (WLTP), has been developed through the United Nations and is ready for implementation in the EU as early as 2017.

In the new test procedure, for example, the weight of the vehicles will be reflected more realistically—one of the aspects that will help to reduce the current fuel-economy gap.

It is important to clarify that this analysis is not intended to incriminate vehicle manufacturers. The NEDC was not originally designed to measure average fuel consumption or CO2 emissions, and some of its features can be exploited to obtain artificially low results. Manufacturers appear to be taking advantage of permitted flexibilities in the NEDC, resulting in lower CO2 emission values. The new Worldwide Harmonized Light Vehicles Test Procedure (WLTP), with its more dynamic test cycle and tightened test procedure, is expected to result in somewhat more realistic values. … A key aspect of the transition will be an appropriate conversion of existing CO2 targets and CO2 based taxation schemes from NEDC into WLTP. Unintended flexibilities that are currently part of the NEDC should not be accounted for when transitioning to WLTP. Otherwise there is a risk of undermining the introduction of WLTP and making most improvements achieved with the WLTP obsolete.

At the same time, the WLTP will not resolve all open issues, and the new procedure may itself have vulnerabilities that have not yet been identified. In light of this, it is important to complement the WLTP with additional measures, such as testing and regulating the efficiency of vehicle air conditioning systems. More importantly, some form of in-service conformity testing should be required to ensure that reasonable emission values are achieved not for a single test vehicle alone but for all cars sold to customers and driven on the road.
—“From Laboratory to Road: 2014 Update”

http://www.greencarcongress.com/2014/09/20140928-icct.html

Also -

Resources

Peter Mock, Uwe Tietge, Vicente Franco, John German, Anup Bandivadekar, Norbert Ligterink, Udo Lambrecht, Jörg Kühlwein, and Iddo Riemersma (2014) “From laboratory to road: A 2014 update”

****

They all have past 2008, gotten real clever @ gaming the system although some were way ahead of that.
 
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My pontiac G5 GT 2.4L 5 speed get a avg 27mpg mix driving. My 2008 saab 9-3 aero XWD with the 2.8L turbo gets 22mpg mix driving. If i take the saab on a long drive the best i got on the highway doing 70mph was 33MPG. The saab seems to me better on gas driving back and fourth to work all highway. Where the G5 is better around down then the saab.
 

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LOL thats right big brother in places like the EU is gonna rig skew EU government C02 testing in favour of bringing out higher C02 numbers in the tests so they milk collect more tax revenue out of the EU motorists wallet. It called legalised stealing.
Doesn't the increasing gap indicate exactly the opposite? Car makers offer more and more 'ringer' tech that fools economy testing regimes in order to avoid C02 taxes.
 
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