The Myth of Ever Increasing Fuel Economy

American Thinker ^ | May 23, 2009 | R.H. Higgs

[neverdem]

Two months ago I did what most environmentalists would consider unthinkable. I purchased my first 4X4 vehicle.

Since I wasn't planning on using it as my primary vehicle, I wasn't willing to shell out the multiple thousands of dollars involved in purchasing new. The logical choice was to pick an early 1990's model which was still in good condition. I found one with electronic fuel injection, A/C, and power everything. Even though it's verging on its twenty year birthday, it is still a sharp looking vehicle in very good condition.

So, imagine my surprise at the responses of my friends and acquaintances.

The comment, "You bought what? What a gas guzzler!" was generally quickly followed up by, "you should have purchased something newer for better gas efficiency."

Does that really make sense? Have vehicles improved so drastically compared to older models? Would I be better off tripping the parking brake on my sweet ride and pushing it over a cliff? While many environmentalists would automatically agree with that sentiment, are the savings actually that significant?

I was nursing a little bit of insecurity about my investment, so I went to the EPA's fuel economy website in order to get some hard numbers. I found something very surprising. When comparing my 1993 4X4 to a current offering with a similar size engine block, transmission and carrying capacity, I found the newer model exceeded my fuel economy by an astonishing: 1 MPG.

"No kidding? Whew, I can live with a loss of 1 MPG. I dodged a bullet there!"

The story doesn't end yet. On May 19, 2009, the AP carried the story of Barack Obama and his new "tougher" fuel economy standards. These new standards would require passenger vehicles to achieve 39 MPG and light trucks, 30 MPG. This would result in an overall fleet average of 35.5 MPG. While the media lovingly touted these new standards as progress, I went back to the numbers.

Knowing what I did about my 4X4, I decided to compare the economy of other typical vehicles through http://www.fueleconomy.gov/. In comparing the numbers, I tried to use similar engine sizes, transmissions and other relevant equipment in order to determine whether the evolution of a vehicle over twenty years improves the fuel economy on any comparable newer model. The results are an eye opener.

Toyota Corolla

Records on this vehicle go all the way back to 1985. Throughout the time frame of 1985-2009, it was offered in front wheel drive and a four speed automatic transmission. The only change came in 1993, when the engine displacement was increased from 1.6L to the current 1.8L.  

This is interesting isn't it? The trend of the average fuel economy climbs only slightly between 27 to 30 MPG. Maximum highway fuel efficiency peaked in the early 2000's and then fell back around 35 mpg for the remainder of the decade, essentially unchanging for 10 years. Overall, fuel efficiency gain for highway driving increased only about 10%, city had an increase of 8% both over the period of 24 years.  Typically the auto industry redesigns their vehicles every four years or so, therefore this scale represents at least five separate design cycles of the same model.  Since the Corolla is on its 10^th generation and this chart started in the middle of the fifth generation, it seems Corolla is reflecting typical industry practice.

Considering this class of vehicle has an emphasis on fuel economy, it seems reasonable to expect significantly larger gains, wouldn't you?

Ford Taurus

This four door sedan was easy to compare model years. During its production run of 1989 to 2007, it was offered with a 3.0L V6 engine, a four speed automatic transmission and front wheel drive. In 2008 the base model engine displacement increased to 3.5L.

Even considering the multiple design cycles over twenty years (five for Taurus) there is little to no change in fuel economy. It seems reasonable to assume the engine systems were improved over this 20 year cycle. Including all technological improvements between 1989 and the present, the average fuel economy has continually hovered around 21 MPG. With a trend like this, it seems extremely difficult to nearly double the fuel efficiency on a similar platform in only seven short years.

Ford F-150

Looking through the EPA entries, the high output model of this truck has had more configuration changes than the other vehicles. It makes an interesting point.

In 1985, the truck was offered with a 5.8L V8 and 3 speed automatic transmission. In 1990 one change was made, the 3 speed was discontinued and replaced with a 4 speed automatic.  In 1997, the engine displacement was reduced to 5.4L and finally for the 2009 year, the engine was again reduced to 4.6L.

Why is this interesting?

Notice at 1990, when the transmission was upgraded, the highway economy jumped. This is to be expected, because higher gears allow the engine to be more efficient at higher speeds. Again, in 1997, you see another slight trend upward with the reduction of the engine size. Yet again, in 2009 there is a slight jump with the reduced engine size.

However, even accounting for the nearly 30% average improvement in fuel economy over 24 years, it seems like the average 30 mpg mark is a long way off. In fact, even though engines cannot be continually refined to ever increasing heights of efficiency, let's assume they do for a moment. Let's also assume this historical data is representative of the trend for this type of vehicle. With these assumptions, if the average economy is 12 mpg in 1985 and 16 mpg in 2009, at the current rate of progress, it would be 2093 before this particular model of light truck would have a fuel efficiency of 30 mpg.

This is not to impugn the automotive industry, if it were possible to design an engine that achieved 200 mpg, I have no doubt they would have succeeded by now. The automotive market is competitive like any other and companies are always trying to maintain an edge on their competition.  Achieving any exponential increase in fuel economy would make them market leaders in a moment. Unfortunately, internal combustion is a mature technology which we understand very well. Because the basic concept has stayed the same for a hundred years, engineers spend their time making minute tweaks in order to achieve gains of one type or another.  These gains are not mutually inclusive. An engine sacrifices power and torque for fuel efficiency or vice versa.

Engineering is the science of making compromises in order to create a product which functions. If an engineer increases the gearing in a transmission, the vehicle gets heavier; at a certain point, increased gearing brings no fuel efficiency benefit thanks to the extra weight. If an engineer decreases engine displacement, efficiency will increase to a point, then decline as the power to weight ratio becomes unfavorable. This will continue right up to the point where the vehicle is unable to move its own weight.

Another option is to reduce the weight of the vehicle to get the gains Obama so desires. Continuing down this path, the automobile quickly becomes a motorcycle.

As many others have pointed out, this results in designs where a vehicle becomes lighter and proportionally less safe as the inertia is decreased.

That's obvious, but not the point.

The point is, since the 1970's fuel economy has become one of the yardsticks by which all vehicles are measured. Arguably, to some it has become the most important. People seem to naturally assume that a new vehicle is going to perform yards above that of its predecessor. Hence, there becomes an expectation that fuel economy can and will always increase. Looking at the plotted fuel economies of the above representative vehicles, this expectation doesn't show true.

We're expecting miracles from a technology which has truly reached its limits. This is unreasonable. For each class of vehicle, the unique characteristics of its mission almost appear to dictate its fuel economy. An economy car isn't comfortable for carrying a family of five and a sedan will never carry a couple yards of topsoil for your garden. The sedan will never rival the economy car in fuel efficiency because it has different requirements it has to meet.  From the buyer's standpoint, within vehicle classes, a 10 year old car is economically the same as a new one.

By proposing a set limit for economy on all classes of passenger vehicles, Barack Obama has basically said one of two things: In 2016, he wants only economy cars to be sold in the US or he is instructing car companies to squeeze gas from a stone. Since he cannot change the laws of physics, I envision the date those proposed standards take effect will either be repealed by the next administration, or continually be delayed.

This is just another dictate similar to all the rest of Obama's plans: not based in reality, but wishful thinking.

Note: Many will note I only compared regular gas vehicles and did not include hybrids and alternative fuel vehicles in the mix. Neither type of vehicle has enough fuel efficiency history to establish a trend. At most, the oldest models of hybrid vehicle are currently on their second design iteration and alternative fuels have not yet been shown to be viable. Regardless, there is no reason for me to believe that any of these variations on the internal combustion engine are immune to the same constraints that govern modern automotive design.

[tina07]

We’ve only been to Pocono multiple times. Last time was in ‘07 and it rained, no fun at all! After the third downpour we called it quits and then of course the sun came out on our ride home to NJ, and the race did go to the finish.

We went near the track last summer, the July race, just to buy some shirts at the places along the roadway heading for the track. Again it started raining but the race was able to finish later.

Yes, Dover is cool, never been though. My daughter and her husband and a friend went a couple of years back. They sat way at the top and loved the view!

Nice, a motorhome, that’s our dream to do that, drive to races in one of those! We just bought our first home moving here to PA, only took us 30 yrs. to do it, so the motorhome will have to wait for now, lol! We’d like to look into renting one some time, they are awesome inside!

[WVKayaker]

I bought two Ford Focuses in the ‘90s - both cars were total pieces of junk. Never again, never.

My first question is why did buy a second, if the first was junk? The next question is how did you buy a focus in the 90's? The first modelwas a 2000(which was offered in 1999)

My wife drove a Focus over 200k miles... and you are pwnd!

(not hers, but like it!)'92 ZX-5 (4 doors and a hatch. ZX-3 was a 2-dr coupe!)

[WVKayaker]

Before you rent one, look at FL Craigslists. I paid $30,000 for a gently used (16k miles) motor home which sold for $215k new, and it's only 7 years old.

If you are going to FL for a vacation, buy one cheap and resell it at home, after using it! You can find decent ones as cheap as $5-10k, ready to drive! It's the fuel costs that hurt!

I bought a diesel, when it was high. Now, diesel is again cheaper than gasoline. It's a nice coach, with two slides. It makes for "almost home". It even has a washer/dryer!

I have a Dalmation that hates to stay home, and I don't like most kennels! Plus, he barks loud at strangers. I can leave it unlocked...

[tina07]

Thanks for the good advice. I’ll keep in in mind, but it will still be a while before it could ever be a reality. Hubby is laid-off, yup one of the unemployed, so each day and week sets us back more and more. My poor son has been out of work since Christmas eve...

[ntmxx]

Interesting I have too have one the good ones, a 2000 Explorer XLT 4x4 with the HP V6, gets 14-16 city, 20 mpg when I drive the new speed limit of 80 Hwy and if I am nice about 22+ Hwy on average. The best car and engine I have ever owned (and I have owned a few name brand muscle cars). Most of this is noise! You really have to ask yourself, if we use less gas will the price stay low, they have to make profit on all those gallons, also if we use less and pay more will the Chinese pay the same; I doubt it. Once we are committed to supposedly using less and saving, will the rest of the world do the same equitably, again I doubt it, so much for everyone working together...

[ntmxx]

Want cheap energy and energy independence!
Then nuclear is the only way to go for mass consumption on the power grid. Further, we need as a nation to improve the technology of co-engine support, known as Hybrid systems. Using engines similar to a 1000cc motor racing cycle engines which could get 60 – 80 mpg, attached to a generator, supplying batteries, driving an electric drive train when extra power is needed the generator will supplement power directly, similar to diesel electric trains. This would be enough to support SUVs economically, pull boats, go up hills without effort and haul a family of 6 or more everywhere…

[count-your-change]

For increased mileage I can buy a free breathing air filter, I can install some expensive spark plugs, that would help, I can install a better or tweak the existing intake manifold and gain just a bit. A really slippery engine oil would help too but not a huge amount. Changing the fan blade to a freer running type might add just a bit of mileage as would the right tires. Maybe an engine controller would help if I use it properly. A less back pressure exhaust system? I don’t know how much that help.

I can do all this for a $1000-$1500. But would I do it for a 3 mpg increase or would it take more? I don’t know.

Piston engine air craft use a dual spark system for safety but it burns the fuel more efficiently, would such a system be feasible for mass produced autos? Kind of depends on the cost of redesigning the engines and production.

My point is that there are things that can be done to increase mileage in gasoline engines besides reducing weight but they’re more costly.

For that reason I would think diesel engines would the best option.

[count-your-change]

“With lighter and smaller cars you get better gas mileage. You also get higher death rates from accidents.”

Quite so. I saw a heavy Cadillac hit a small Japanese car in the rear and the lighter car burst into flames. The poor driver escaped but not before being terribly burned.

And I turned a few tin boxes into scrap with a armored tank known as a ‘75 LTD.

[raybbr]

My only Ford was an ‘87 Taurus. I liked that car till some idiot woman ran stop sign and totalled it. I bought it new and had it for seven years. How are your Taurses holding up? Mine had over a hundred thousand miles and never had a mechanical problem.

[ovrtaxt]

Check out Amory Lovins and the Rocky Mountian Institute (rmi.org). They advocate radical engineering changes in materials (advanced plastics and composites) and energy management (such as the braking system on the Prius) to increase gas mileage.

He’s no enviro-whackjob either. He does a lot of contract work for the military. After all, the less dependent the individual soldier is on the supply of fuel, the more effective and efficient he will be at achieving is objective, and the more men you can remove from the supply chain, the more support you can give to the man on the front line.

[mvpel]

My 2000 Acura 3.2TL has become my commuting vehicle for a 100 mile daily round trip, and with a few tweaks such as better tires and a K&N high-flow air filter, I’m getting 31-32mpg on the highway.

A brand new Ford Focus trumpets 33mpg highway.

[mvpel]

Now, I imagine that a “native diesel” engine would be even better, being designed “from the floor up” with Diesel in mind; however, that is completely disregarding the advances in technologies that could be applied to the engine.

Honda has done just that, with the iCTDI, which can achieve 55-60mpg highway in a Honda Accord.

The problem with diesels is that the EPA-driven emissions standards make most high-MPG new diesel passenger cars, long available in Europe, illegal in almost the entire US.

We could have had 40-50mpg passenger cars years ago, if it weren't for the federal government.

[Yankee]

Regenerative braking has been used in the railroad industry since the early 20th century. It is commonly referred to as “Dynamic braking”.

Locomotives commonly referred to as “diesels” are actually “diesel-electrics” with the diesel engine driving an generator or alternator which furnishes electricity for the traction motors which are geared to the drive axles.

By reversing the polarity of the field winding of the motors, they operate as “mini-generators” producing electricity which is wasted as heat through air cooled resistor grids on the roof of the locomotive. The mechanical resistance of the motors is used to hold train speed on a downgrade, or slow the train on more level sections of the railroad and reduce the use of the air brakes.

On some straight electric locomotives the regenerated electricity was returned to the overhead catenary system. The Chicago, Milwaukee, St. Paul & Pacific RR used this system on their two electrified divisions in the Rocky and Cascade mountain ranges.

GE has a prototype diesel-electric locomotive which uses battery banks to store the electricity so that it can be used on the next acceleration after braking. The biggest obstacle to wide scale application of this technology is the weight of the battery banks which makes the locomotive exceptionally heavy.

[mvpel]

Actually, the question should be..."How FAR can it travel on the batteries after the gas tank is depleted? Every time you slow down, it makes more juice!

I got nearly 34 mpg highway on one tank of gas on my 2000 Acura TL by carefully watching my driving habits.

Instead of jackrabbiting up to tailgate the next guy ahead of me on the freeway like most other people seem to enjoy doing, I maintained plenty of following distance, left home earlier, planned ahead for ramps and lane changes, and didn't touch the brakes at all for about 90% of my 50-mile, 65mph commute.

I can hardly imagine what kind of MPG I would have gotten if I could have driven 55mph without causing a 50-car pile-up.

[mvpel]

Everything has inertia; if it has a mass, it has inertia. A hybrid reclaims energy through the fundamentals of physics. Do you remember any high school or college physics?...

I remember just enough high school physics to know that if you don't press the brakes, you can't take advantage of regenerative braking.

My folks live about 800 miles away. If I didn't have to eat or take a leak for about 13 1/2 hours, I could drive there in my 2000 Acura 3.2 TL stopping for gas only once.

[WVKayaker]

I sold my '90 TownCar last year. It had a 5 ltr. V-8, which gave me up to 25 on the highway at 55. Before that, I had an '89 Continental that a guy sold me a "chip" to help it out. That 6-banger gave me over 40 on the hwy! I should have kept it, but the airbag suspension was going down. It could walk away from a stock Mustang GT.

The owner of Electromotivehad a Cont., and made it a personal project. They were making power for racers at the time!!! It cost me $1500 in 1989! Mass production would lower those costs. I bought it for economy. I was putting 50-60k a year on the road.

http://www.electromotive-inc.com/

[libstripper]

Another option is to reduce the weight of the vehicle to get the gains Obama so desires. Continuing down this path, the automobile quickly becomes a motorcycle.

My old 1972 BMW R75/5 (750 cc, 57 hp.) motorcycle got about 37 mpg, not enough to meet the Usurper's 39 mpg. standard for automobiles. We can all kiss AC and anything else that makes a car comfortable or enjoyable to drive goodbye.

[WVKayaker]

I remember just enough high school physics to know that if you don't press the brakes, you can't take advantage of regenerative braking.

The term "braking" is a technical term. Any vehicle in motion is constantly "braking". Read the article I noted above, and you will get a better understanding than I can give you. I'm just a salesman...

[Jabba the Nutt]

There is no shortage of oil. There is no global warming. Car engines are as close to pollution-free as you're going to get.

There's an unspoken agreement between environmentalist (with emphasis on 'mental') and the oil companies to restrict the supply of oil, thereby providing a price support for the oil companies. The environmentalists get to feel good about themselves for reducing oil consumption.

They get the bennies, we get the shaft. Voters wake up.

[mvpel]

Ah that’s right, such as the engine braking that the transmission does on a non-hybrid vehicle when you’re going downhill and the cruise control is trying to keep you at the set speed. (At least on Honda and Ford cruise controls - I rented a Chevy that didn’t do that and it got me a speeding ticket.)

But regenerative braking can only recapture a fraction of your forward momentum. The rest is lost to rolling resistance and wind resistance. The only reason you’d have range beyond the end of your gas tank is that the charge controller on hybrids prevents 100% depletion of batteries.