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Old 03-10-2023, 08:47 AM   #1
Jon Bailey
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Lightbulb Large cars and trucks are still not impressive on MPG.

There is no reason under the sun a car or truck the size and weight of a Lincoln Navigator or a Toyota Tundra can't achieve 30+ MPG highway. There is no excuse for a Tacoma 4-cyl. to not exceed 30 MPG.

Until practical replacements for fossil fuels come along, the automobile industry should be forced by governments to develop the maximum possible fuel efficiency for the vehicle size and weight class.

Much-higher-MPG cars and trucks, even larger ones, can be achieved a number of ways.

1. advanced hybrid technology
2. developing the most efficient turbodiesel motors possible
3. developing the most fuel-efficient supercharged-gasoline engines possible
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Old 03-10-2023, 08:54 PM   #2
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Re: Large cars and trucks are still not impressive on MPG.

New cars and trucks have very complicated engines that try to get better MPG and reduce air pollution. Electric cars and trucks require electricity to charge their batteries. I don't know why car companies don't make more hybrid cars and trucks.
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Old 03-10-2023, 08:55 PM   #3
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Re: Large cars and trucks are still not impressive on MPG.

I think I understand your disappointment. It might stand to reason that after 100+ years of development of propulsion engines, we might have arrived at something more appealing by now. It's not as if people haven't tried.

Turbines were investigated and tried in automotive applications. Rotary (Wankel) engines were tried. Steam was tried. A nearly dizzying array of configurations of piston engines have been tried, including inline from 2 to 8 cylinders, 60° V, 90° V from 4 to 16 cylinders, W-configurations radial, rotary radial (stationary crankshaft), horizontally opposed from 2 to 8 cylinders, two-cycle engines, pre-combustion engines, and probably several which never even got into the public eye.

Many of these multiple variations have been tried with gasoline, kerosene (diesel and distillates), waste oil/fuel, propane (and LP) gas, CNG, hydrogen, and even vegetable oil.

Compared to present the state of the art of gasoline fueled reciprocating piston engines, all have had drawbacks for varying reasons.

Also bear in mind that the propulsion force is only one part of the equation in distance per unit of fuel used. Weight has a factor, but is effectively negated once a vehicle achieves a steady velocity, other than the frictional losses of tires. And that can be almost completely overcome by using the proper tire. The largest factor is affecting overall vehicle efficiency is aerodynamic force. No matter what propels it, a Lincoln Navigator has to punch a hole in the air it travels through. The two design factors affecting how well if achieves that are drag coefficient (Cd) and frontal area. If you don't know the formula for aerodynamic drag it is:

. Cd x air density x [ (Velocity²) ÷ 2 ] x Area

No engineer can control air density. At any given speed factor (V² ÷ 2) the only remaining engineering design elements are drag coefficient and frontal area. A typical fighter aircraft has a Cd of around 0.15, but some are a bit better, and some are even better than your 155 Howie rounds.

Some of those fighter jets even have a frontal area much greater than a regular Stinkin' Nag-A-vator. The drag factor is a product of that area multiplied by Cd.

VW made a test car in 1980 which had that same kind of fighter jet Cd, measured at 0.15. One person could fit inside it, and it was a TEST car. Some recent production cars have a Cd at 0.22 or very close. The Nag-A-Vator probably has something closer to a sheet of plywood, and not edgewise. I suspect all similar production trucks are in the 0.40+ range depending on options.

According to the boys over in Dearborn, the Navigator is 93.8" wide and 76.4" high. We have to give them the deduction for the advertised 6" ground clearance, and end up with that frontal area. Multiply the dimensions to result in the frontal area of 45.85 ft² for a Lincoln truck. A 4x8 sheet of plywood is only 32ft², so this is almost 1½ sheets. Multiplied by the 0.4 Cd and the drag factor is really up there at 18.34.

No matter what is used to propel that, a finite level of power is required to move that at a finite velocity. As speed increases, the drag increases by a square factor of that number.

Compared to the 45.85 ft² of the Lincoln, a Lockheed F-104A (very small fighter jet) has a frontal area of only 28.62 ft² and an impressive Cd of 0.136. Even though it is almost 22 feet tip-to-tip and 54 feet. long, its drag factor is 3.89. Of course, the power to move that at 1,500+ MPH in the Z-5 afterburner notch is dramatically greater than the Lincoln at 70 MPH. That's probably why the J-79 could do 18,000 pounds of thrust without afterburner, and then more. The Lincoln would possibly fold with that much behind it all at once.

The point there is that efficiency is not all about the engine, and if some of us want to drive a sheet of plywood or more to the grandma's house, efficiency may not be our primary concern, and any propulsion source is going to suffer.
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Old 03-10-2023, 10:47 PM   #4
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Re: Large cars and trucks are still not impressive on MPG.

Also, don't forget that there are many safety requirements levied on manufacturers that pretty much all add weight to vehicles. Adding weight to a vehicle rarely makes it more fuel efficient. Even adding the weight of electric motors for hybrid powertrains and batteries add weight.

Plus, developing new technologies or improving upon current technologies takes money, and no manufacturer is going to fully absorb such costs. And how many people want to pay exotic car prices for their daily-driver just so they can get that latest cutting edge weight-reduction and/or fuel economy improvement technology?

-Rod
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Old 03-10-2023, 11:01 PM   #5
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Re: Large cars and trucks are still not impressive on MPG.

I didn't mention that previously, but you are correct about at least one aspect (if not all of them) that the NTSB would probably frown upon the nose of a street vehicle looking like this just to get better fuel efficiency. Pedestrian kabob, anyone?

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Old 03-11-2023, 02:01 AM   #6
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Re: Large cars and trucks are still not impressive on MPG.

The new "gee-whizz" Ford Maverick has some shortcomings in spite of running on fumes.

Besides the meager 4.50" box, the rear seat can't fold truly flat to make a serious rear cargo area for ice chests and duffel bags.
Going to the Ford website, this stupid thing is an overpriced thing and can get to over $30K OTD if you add the XLT package just to avoid the el-cheapo vinyl seats and the all-wheel drive option. I hope Toyota does a better job when they get into the econo-pickup market. A new Toyota Stout compact truck is in the works. There is also talks of a Tacoma hybrid in the near future. Your best bet for now for an "economy truck" is a good older 4-cyl. Tacoma that can still get 20-something highway. Paying the new price for brand new stuff boasting better MPG often more than offsets any long-run fuel savings. Between Big Oil and Big Automobile, the bottom-line conspiracy is to rob consumers.
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Old 03-11-2023, 02:06 AM   #7
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Re: Large cars and trucks are still not impressive on MPG.

Toyota Tacoma double cab has a super smart fold-flat setup. You can make a table to put a large cooler on one side while a backseat person is seated on the other side.
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Old 03-11-2023, 08:07 AM   #8
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Re: Large cars and trucks are still not impressive on MPG.

One of the problems is the buying public. Fuel economy just doesn't sell.

After the 1973 oil embargo, I predicted that engines would get smaller to get better fuel economy. Boy was I wrong! The exact opposite happened!

Yes, the late 1970's resulted in heavier cars to accommodate crash mandates, and emissions limits and fuel economy standards resulted in anemic engines, but by the 2000's most of that had been clawed back.

But the buying public moved onto SUV's! Those are heavier still, and it's harder to make an SUV both lighter and as aerodynamic as a car - but the public didn't care! Notice how all the vehicle manufacturers produce a lot more SUV's and fewer cars. Even Porsche produces SUV's!

But the buying public likes new features, even those that add weight! It's an uphill battle.

And the buying public doesn't like it when the government steps in to mandate changes. Certain political parties have that as a basic, unassailable feature. Don't expect any changes for the foreseeable future.
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Old 03-11-2023, 03:11 PM   #9
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Re: Large cars and trucks are still not impressive on MPG.

I can't believe that Ford was bold/oblivious/ignorant enough to resurrect the "Maverick" label for anything. It seems doomed from the start, providing it ever starts.

Before considering anything new, walk through a salvage yard (some of them still allow this) and survey the various brands and types of vehicles you might be considering. It can be very revealing. Around here, no one can find a Toyota "truck" more than 10 years old without serious frame problems. They are not alone, but are easiest to pick on since they've already had two forced recalls for frame failures in recent history and apparently haven't figured it out yet. Not many of them have engines or transmissions stripped out, so that's a "plus" indication that they have good service life, and lots have body panels stripped off due to drivers texting instead of driving, but the frames seem to be a different story.
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Old 03-11-2023, 06:48 PM   #10
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Re: Large cars and trucks are still not impressive on MPG.

Quote:
Originally Posted by Blue Bowtie View Post
I can't believe that Ford was bold/oblivious/ignorant enough to resurrect the "Maverick" label for anything. It seems doomed from the start, providing it ever starts.

Before considering anything new, walk through a salvage yard (some of them still allow this) and survey the various brands and types of vehicles you might be considering. It can be very revealing. Around here, no one can find a Toyota "truck" more than 10 years old without serious frame problems. They are not alone, but are easiest to pick on since they've already had two forced recalls for frame failures in recent history and apparently haven't figured it out yet. Not many of them have engines or transmissions stripped out, so that's a "plus" indication that they have good service life, and lots have body panels stripped off due to drivers texting instead of driving, but the frames seem to be a different story.
Apparently, Ford cannot build enough Maverick trucks to satisfy the demand. Maverick trucks have already started.

I'm a baby-boomer American I think practical and frugal when shopping for products. Baby-boomers and later generations did not raise their young ones sensibly.

I just don't have money growing on my trees.

My 1995 Corolla DX has not one speck of rust on the frame or body anywhere. Has Famous Toyota Reliability and longevity slipped?
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Old 03-11-2023, 09:13 PM   #11
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Re: Large cars and trucks are still not impressive on MPG.

I caught on that the '22 Mavericks sold out very fast. Obviously, P.T. Barnum hit the nail on the head. I was born when Eisenhower was in office, and the years since then have conditioned me to the point that no one is going to convince me that a Ridgeline or Maverick or any "truck" with a unibody and no frame is really a truck.

I understand your '95 is in very good condition, and is probably pretty mechanically reliable. That's nothing new. The trucks they made have a different issue from mechanical reliability. The frames are subject to rapid and severe deterioration, most likely due to oversights in their design. I know specifically of two such examples with the bodies in relatively very good condition, but the frames deteriorated to the point where they can't pass a safety inspection. Whatever they did to try to make the frames impervious seemed to actually make them worse, from the middle 1990s all the way through 2009. I suspect that your Corolla may have been treated differently, perhaps more like a priimed/painted body part instead of a frame rail on a truck. Just be mindful that the fully boxed areas near the front need to be monitored closely since those areas hold moisture and are among the first to go away. Just keep it washed out and touched-up, and it could stay that way.
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