Skip to comments.Why car makers lie about fuel consumption (in Europe)
Posted on 04/28/2012 12:06:31 PM PDT by Olog-hai
There are lies, damn lies, statisticsand official EU car fuel consumption figures. I and others have been banging on about this for years; the figures quoted by manufacturers in their ads usually (but, interestingly not always) bears absolutely no relation whatsoever to what happens in the real world.
To get those official figures, new cars are subjected to something called the New European Driving Cycle, a series of short runs on a rolling road where the car is accelerated, put on a short cruise and decelerated under laboratory conditions. All the car makers have to put their cars through the same test, so on this level, there is no trickery involved. The idea is that the EU has created a level playing field upon which the performance of all cars can be judged.
But it is not as simple as that. Because this is where it gets clever, and some trickery DOES creep in. Some years ago, manufacturers realized that to score well on the official tests, they could tune their engines for maximum efficiency on the rolling road cycle. This was particularly the case for small turbocharged diesel or petrol engines and hybrids. For instance, the engine could be set up so that the turbocharger simply does not kick in during the cycle. But take the car out onto a real road and to get the thing to move at all, the turbo will be needed, massively increasing consumption.
(Excerpt) Read more at hanlonblog.dailymail.co.uk ...
In america, cars get better mileage than the official numbers. I think this is because they test it with the AC running nowdays. It was one of the gimmicks the government came up with to force cars to get better mileage without changing the official CAFE requirements.
Werner Karl Heisenberg figured this out quite a while ago.
In the past, I found real world US mileage figures to be overestimated for automatics and underestimated for manuals (coasting is illegal though - I’d NEVER do that).
>>In america, cars get better mileage than the official numbers.
You must be that slow guy in front of me! LOL. My car doesn’t even get close to the EPA mileage.
Ethanol was designed by GOD for personal internal combustion, not to be used for getting somewhere.
Not surprising. Ethanol (76,100 BTU/gallon) doesn’t compare favorably with gasoline (114,100 BTU/gallon).
All i know is the wife and I went 3-4 years with only one vehicle since my work was so close to home. Got a new job a few months ago that is about 50 miles away. With gas prices and distance we decided to get a prius. No regrets they advertise 48/49 mpg. I’m averaging 52-56 depending on how quickly I accelerate - which is usually based on traffic at the time. With prices the way the are I couldn’t be happier.
Oh and we saved on insurance during those 3-4 years and put all that money back and scrimped and saved in other places rather then spending it. We paid flat for the car up front - no loans to worry about or be held over our heads.
Way to go! Screw Zer0 and The Goldman Sack.
Thank you Jesus for having our government regulate the shiite of these cheaters!
Hmm. They must run these tests at idle then, because the turbo these days kicks in very early - ~1500rpm or so. With VTG turbos etc. the days of "turbo lag" are long gone. Sounds like more BS "journalism". On the open road my Audi A4 quattro with the 2 liter turbo gasoline (200 hp) engine is close enough to what Audi states. And any sane person knows that stated figures are always a bit optimistic vs. actually driving in traffic. (I can get even better mpg than stated, but that takes the fun out of driving...)
Full sized 60s pre-smog cars got much better mileage than today’s hightech econoboxes.
The turbo doesn’t have to start charging at all; it can be bypassed, even. It’s not like a supercharger that’s belt-driven or chain driven or operated by the engine via other means.
Only in $/mi based on gasoline prices.
S/C’s can be bypassed too. Besides, with a clutch of some type on the front, they can easily be not driven at all, if desired.
Gets even easier to do in the case of computer-driven superchargers and turbochargers.
1960 Corvair: around 20 mpg, 0-60mph in just over 21 seconds.
2009 Corolla: around 30 mpg, 0-60mph in less than 9 seconds.
Sure, but fix the excess camber on the Corvair and get up to 20.1.
Not so much. This road test of the 1962 Impala SS puts the normal range at 10/13 mpg.
...and a 1969 Caprice at 8/11 mpg!!
Fuel was cheap so no-one really cared.
I think this is because they test it with the AC running nowdays. It was one of the gimmicks the government came up with to force cars to get better mileage without changing the official CAFE requirements.
The A/C change had to do purely with Cadillac ,, they had a trigger set in the engine computer back in the 1980’s and early 1990’s that would run the engine just right for emissions testing with the A/C OFF .. the car ran like crap ,, drivability really stunk but it passed the emissions tests ... with the A/C ON the computer ran on a totaly different fuel and ignition map and ran fine but flunked emissions ...
How about filling the tank with fuel, driving it until the fuel gauge indicates it is prudent to refill the tank, then dividing the total distance driven since the last fillup, by the amount of fuel needed to again top off the tank?
Seems like a pretty reliable indication of the mileage potential. In real time and in real conditrons.
Years ago, Mobil held a “Grand Canyon Economy Run”, which provided just such figures on a real driving course, all vehicles in direct competition, following the same road and driving conditions.
Studebaker Champions came up with some pretty impressive numbers. And this was back in the late 1940’s and early 1950’s.
I drive a 2005 Chrysler 300C and get over 30 mpg highway. I was looking at a new 2012 300 and the sicker claimed only 25 mpg. Same engine, same accessories etc.
That’s how it is now. Rather than increase the CAFE requirements(which would make people angry and requires government action) they did the back door method by having the EPA change the parameters of their fuel mileage tests. Cars have more horsepower nowdays and if you use that HP stupidly, your mileage goes down real fast. In other words, your mileage varies more depending on how you drive. That makes it easier for the EPA to get the mileage results they want to get by adjusting the parameters of the test.
Higher power would mean less throttle required to match the acceleration graphs on the test equipment ,, should mean higher mileage ... at least as far as a hemi 300c is concerned as the car is substantially unchanged... I don’t think the test has changed much ,, you should be able to make valid comparisons between current and prior years ... http://www.nhtsa.gov/fuel-economy
Lower powered cars operating at closer to max power are more efficient than high powered cars operating at lower power levels. Stated another way...
a 100 horsepower engine operating at 100% output is more efficient than a 200 horsepower engine operating at 50% output. Both are generating 100 horsepower but the more powerful engine consumes more fuel.
If the turbos on these cars were bypassed to fudge the test in a certain rpm range, owners would immediately notice and complain. Like I said before, the days of turbo lag are long gone. Today there is seemless, smooth power from just above idle to close to redline.
Anyway, there are dozens of car magazines (if anyone reads those anymore) and hundreds of car-specific websites that will tell a prospective owner what milage can be realistically expected.
Everyone knows that the “officially” stated figures were derived from some test under lab conditions and may (will!) vary from the real world. All that those figures are useful for at best (if one really cares at all) is as a relative measure between different cars.
That 25 mpg hwy is actually the same as the sticker in 2005 ,, EPA shows that 2007 and earlier years mileage estimates do not compare directly ,, looks like a calculation change rather than a test change .. http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=20966 click on “view original EPA mileage” about mid page.
The ones I drove got between 12-18 mpg. '69 Catalina/'69 Firebird, etc. Had a '61 Chevy belair with a 235 cu 6 in it and it was lucky to get 20 on the highway. You must have run into some extraordinary full size '60s cars.
I understand about pumping efficiencies, however cars typically cruise at about 10-15% of rated power with huge reserves ... if we were talking about 50% power and 100% power that’s one thing ,, what we have is a car using 6% power to cruise rather than 8% of it’s power ,, CARS ARE NOT AIRPLANES.
In the 60s, the only benefit to getting a smaller engine was the car was cheaper to buy. Smaller engines didn’t cost much less to operate and they wore out much quicker. Most people wanted the biggest engine they could get.
Every engine is different .. what you need to see is a chart/graph of BMEP vs. Fuel Burn to determine the engines most efficient RPM ... with a load equal to whatever “road horsepower” (rolling resistance plus aerodynamic drag) you need for a certain speed.. BMEP alone is useless on a dyno if you are just looking for max horsepower.
Generally speaking, the smaller engine operating at closer to peak output is more efficient. If this weren’t true, hybrid cars would not get better mileage than non-hybrids.
How many forward gears on the Corvair though? If youve got the two-speed automatic, you cant expect high acceleration. Never mind dual overhead cams, multiple valves per cylinder and electronic fuel injection making yet more of a difference, curb weight rounding everything off. Comparison of apples to apples would be more like itthe original Corolla E10 (first year in US was 1968) came with an OHV 60-hp inline four-cylinder, with transmission options of four-speed manual and two-speed automatic. (Cant find performance figures for the automatic though; the stickshift managed a 0-60 in 16.8 seconds and quarter-mile time of 20.0 seconds, and I dont see the two-speed automatic beating that.)
The thread concerned mpg. Today’s vehicles are heavier and faster, but still get better mpg.
Newer mid-size (and even larger) cars do 0-60 in under 7 seconds and get 25+mpg in mixed driving, not to mention handling much better. Mid-’60s muscle cars were barely faster and got half the mpg.
But there was something enjoyable about those big bench seats and lots of elbow room. And there was no beeping and buzzing! Many vehicles today give the feeling of being strapped in a padded bathtub.
The truth is that the figures are only useful for comparison purposes. No set of testing can come even close to a real-world scenario.
Is it where HP/torque cross and BSFC is the lowest or a point where volumetric efficiency has peaked? Yes airplanes engines are different...
Still a vast gap in technology. Also, big block V8s were in their infancy in the mid-60s. Theres going to be a wide gulf between the capabilities of a 24-valve 4OHC V6 multi-port EFI mated to a 6-speed automatic and that of an OHV V8 2BBL mated to a Powerglide 2-speed automatic (even the base-model 2012 Camaro V6 has 325 horses, a number youd be lucky to get with the 327-cid small-block V8 of the mid-60s). The sheet metal on the 60s cars, though, is quite another story. And no, not all new cars are heavier than 60s cars; you wont see too many new cars over the 5,000-lb mark.
Newer mid-size (and even larger) cars do 0-60 in under 7 seconds and get 25+mpg in mixed driving, not to mention handling much better. Mid-60s muscle cars were barely faster and got half the mpg
This is the type of car I was talking about, and not with the powerglide slushbucket...I've heard and seen 21 mpg or better.
If you consider the weight of the Bel air, which had a full frame, and compare it with modern cars, I think it fares pretty well. The V8s and automatics not so much, and certainly not the muscle cars.
The advent of fuel injection could have made cars very fuel efficient were it not for overkill by the emissions freaks.
EFI, electronic ignition and the converter all vastly improved the driveability, fuel mileage and emissions of any gas powered vehicle. Other "improvements" did not.
The "smog pumps" AIR tubes, miles of vacuum line and closed loop carburetors were all crap and have for the most part disappeared from production vehicles.
I fully believe that a good portion of the fuel consumed in today's cars is not for the operation of the engine, but to optimize the burn in the converter, hence the downstream O2 sensors.
If they were to simply shoot for the leanest possible fuel ratio at any given time, without compromising performance when needed, nor jeopardizing combustion chamber components, they would have accomplished the same or similar emissions results.
After all, it would seem that the less fuel consumed per mile, fewer emissions would be created.
Aerodynamic are a big plus (but often result in some butt-ugly cars) and the ubiquitous automatic is a minus on mileage.
My point in a nutshell; currently the producers are forced to tune for emissions, your mileage and wallet be damned.
Those 0-60 times from the sixties were high because of poor tires.
from memory so I may be wrong on some of the details:
The 1970 Chevelle 454 SS was the fastest factory-stock car in the world in the 1/4 mile ever made and remained so until the Buick turbo GNX of the 80s surpassed it. I don’t know what car ended up beating the GNX in the 1/4 mile but my guess would be a turbo porche of some kind. The Chrysler hemis were faster than the chevelle but not while in stock condition. They made more stock horsepower but couldn’t hook up well enough to make use of the power and possibly had the wrong gear ratios. The chryslers needed to be tinkered with to get them work right in a 1/4 mile. The hemi had a lot more potential than the chevy but you had to work at it.
We should compare the ‘70 chevelle SS and the late 80s model buick GNX to a current mustang and camero and see what those 0-60 times look like.
Modern engines run lean compared to old engines. The old method of tuning the really old carburetors(1950s) was to richen the mixture to prevent detonation, over heating, and hard starting, and backfiring out the carburetor. Hot rodders would lean out the mixture to get more power but this caused other problems.
The function of a throttle is to impede the flow of air into the engine. This has two effects: (1) reducing the amount of air per stroke; (2) adding drag by forcing the engine to work pumping vacuum. The latter effect is in many cases the more significant one, but the work spent pumping vacuum, which can be significant at low throttle, is essentially wasted. Such waste is much greater in a large engine at low throttle than in a small engine at wide-open throttle.
I do drive conservatively on the highway. I accelerate rapidly to the speed of traffic (that 5.7 liter engine does a good job of it) then kick it into cruise control. In town is another story.
I bought the car used, mint condition and 5 years old with just over 50,000 miles. The used car sticker on the widow showed 18 mpg and I think that chased people off. I didnt care and wanted it, the price was far below Blue Book. It was comfortable, looked new and was a true luxury car my first one. My old car was an 83 Camaro Z28. Great handling, great acceleration but I blew the engine. Not all that comfortable either.
My 2010 Camry has 268 ponies, hits 60 in a squoonch under 6 seconds, will top 140mph 9still pulls strong at 120) and gets 23 mpg locally and has hit 32 mpg on the highway at 65 mph (will get the advertized 28 mpg and up to 30 mpg at 70-75 mph). A lot of today's cars combine some pretty good power/performance and mileage.
I remember mileagae taking a hit when they introduced the "pollution pumps" and the seemed to lower the horsepower to help compensate, but the combination of performance/economy stayed in the "suck" mode.
Although not interesting for any other reason. I’d like to see what would happen to the mileage figures if you took the 1961 Bel air, straight six, three speed manual, and field-tested it for mileage with the 10% ethanol.
Then retrofit it with an engine, same CID and compression ration, equipped with a monitored EFI like Megasquirt, a stand-alone EFI, EGR valve, PCV, and converter.
Then run the same tests with a 5 speed and higher final drive ratio.
It would at least be a pretty good old car to drive around in.
“a stand-alone EFI”
Sorry, I meant a stand-alone HEI.
“Higher power would mean less throttle required to match the acceleration graphs on the test equipment ,, should mean higher mileage ... “
That’s just silly.
You can’t get free power, it all has to come from the fuel.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.