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NHTSA may require 62 mpg by 2025

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Ahem.. My car gets well over 62MPG in most scenarios. Everyone will be driving >2000lb 2 seater hatchbacks. 😀

2025 is a long time away. I bet we will have a production electromagnetic valvetrain by then. That alone will significantly increase overall ICE efficiency. Combined with more and more aggressive hybrid systems, hopefully using the highest energy density storage medium of the time, I bet we will see very significant advances in fuel economy in the next 15 years.
 
jlee said:
Cars are making a lot more power now, but mileage hasn't improved a whole lot. New cars are heavy. 🙁


Top Ten High MPG Cars – 1995 Model Year:

•Honda Civic HB VX 4-cyl., 1.5 liter – MPG: 47 city / 56 highway
•Honda Civic HB VX 4-cyl., 1.5 liter – MPG: 44 city / 51 highway
•Geo Metro 3-cyl., 1.0 liter – MPG: 44 city / 49 highway
•Suzuki Swift 3-cyl., 1.0 liter – MPG: 44 city / 49 highway
•Honda Civic 4-cyl., 1.5 liter – MPG: 42 city / 46 highway
•Honda Civic 4-cyl., 1.5 liter – MPG: 40 city / 45 highway
•Geo Metro 4-cyl., 1.3 liter – MPG: 39 city / 43 highway
•Ford Aspire 4-cyl., 1.3 liter – MPG: 36 city / 42 highway
•Honda Civic Del Sol 4-cyl., 1.5 liter – MPG: 35 city / 41 highway
•Nissan Sentra/200SX 4-cyl., 1.6 liter – MPG: 30 city / 40 highway

http://www.mpgomatic.com/2007/10/23/cheap-high-mpg-cars-1995
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These mileage ratings are based on the old less strigent system.

If you go here you can see what all these cars are rated using today's sytem.

The 1st place Honda Civic HB would be rated at 39/50 using the current system. The 10th place Nissan 200SX would rate at 26/36.
 
zerocool84 said:
Umm that's diesel. Diesel engines don't sell well here in the States and it costs a lot more money to make diesel as low emissions as the government wants all cars to have which is why they are pretty much only on nicer cars. All that technology they have to put in the exhaust costs money.
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Yeah the exhaust system for the Jetta TDI costs about 4k if you look at the bare parts, kinda ridiculous.
 
Meh...whatever. Not like my commute is anything worth fighting for 400-500hp I can't possibly use. I may as well drive a fiberglass egg that goes 50mph max and gets 80mpg because I'm lucky to see 50mph on my commute on a good day. Imagine how many eggs we could cram into a lane on the freeways! We could have one lane for commercial vehicles (which includes pickup trucks) and old fashioned fullsized gasoline powered passenger vehicles and make 6 lanes out of the remaining 3 for egg sized vehicles and motorcycles! I'm all for that!
 
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Pariah said:
These mileage ratings are based on the old less strigent system.

If you go here you can see what all these cars are rated using today's sytem.

The 1st place Honda Civic HB would be rated at 39/50 using the current system. The 10th place Nissan 200SX would rate at 26/36.
Click to expand...

Obviously it depends on your driving style and scenarios, but I tend to get closer to the old numbers than the new.
 
zerocool84 said:
Umm that's diesel. Diesel engines don't sell well here in the States and it costs a lot more money to make diesel as low emissions as the government wants all cars to have which is why they are pretty much only on nicer cars. All that technology they have to put in the exhaust costs money.
Click to expand...

A generator motor operates at a constant throttle setting, simplifying the emissions spectrum. Also, considering the hybrids will undoubtedly be plug-in, the generator motor wouldn't even be running for most commutes.
So we're talking about the emmisions of a tiny, rarely used motor compared to that of a MUCH larger, constantly used motor running through a completely variable rpm and throttle range.

Even if the generator motor put out twice the pollution on a PPM basis, on a per-mile basis it would probably be tens or hundreds of times lower.

I wouldn't worry about any super-high efficiency motor being regulated out of existence.
 
Eli said:
Ahem.. My car gets well over 62MPG in most scenarios. Everyone will be driving >2000lb 2 seater hatchbacks. 😀

2025 is a long time away. I bet we will have a production electromagnetic valvetrain by then. That alone will significantly increase overall ICE efficiency. Combined with more and more aggressive hybrid systems, hopefully using the highest energy density storage medium of the time, I bet we will see very significant advances in fuel economy in the next 15 years.
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Fiat already use a electrohydraulic intake on their new multiair engines.
 
JulesMaximus said:
Meh...whatever. Not like my commute is anything worth fighting for 400-500hp I can't possibly use. I may as well drive a fiberglass egg that goes 50mph max and gets 80mpg because I'm lucky to see 50mph on my commute on a good day. Imagine how many eggs we could cram into a lane on the freeways! We could have one lane for commercial vehicles (which includes pickup trucks) and old fashioned fullsized gasoline powered passenger vehicles and make 6 lanes out of the remaining 3 for egg sized vehicles and motorcycles! I'm all for that!
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Not everyone lives in socal.
 
Eli said:
Obviously it depends on your driving style and scenarios, but I tend to get closer to the old numbers than the new.
Click to expand...

I'm not debating which standard is more accurate. Just pointing out, that if you are going to examine the evolution of fuel efficiency you can't compare ratings using 2 different systems, that will give you meaningless results.
 
I was listening to NPR about the X-prize for these high mileage cars. Some of them get 100mpg but only weigh like, 800 pounds or something. The last thing I want to do is drive one of those and get run over by a truck.

If you really want (almost) no CO2 emission, ride a bike, seriously.
 
Agree. I want a car that both take a hit and give one if needed. Also to be able to get out of it's own and other car's way, if needed, in a big hurry. Hybrids can't do that. Small cars for me present too much potential for occupant injury and are not roomy enough inside.
 
The Boston Dangler said:
every time you brake to a stop, the kinetic energy is turned into heat which is then dissipated into the air. what the hell are you talking about?
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The fact that the kinetic energy was used to actually move the car is considered waste? I agree with the wasted heat going out the tailpipe (although not at 75&#37😉, but I think recapturing the energy from braking is icing on the cake.
 
This would basically be a defacto mandate for electric cars because of the way they calculate fuel millage. My understanding is that they convert the amount of energy in a gallon of gasoline into electrical energy and use that as the conversion to get from miles/kwh to mpg. The reason that this is bullshit is that it ignores the inefficiencies in generating the electricity in the first place. So you can have a car that gets 100 mpg equivalent, but if the coal power plant was 50% efficient generating the electricity it becomes a lot less impressive.

Electric cars can certainly do better than gasoline even when you consider generating efficiency, but the net numbers would be a lot less impressive.
 
Kelvrick said:
The fact that the kinetic energy was used to actually move the car is considered waste? I agree with the wasted heat going out the tailpipe (although not at 75%), but I think recapturing the energy from braking is icing on the cake.
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the chemical energy in fuel is turned directly into thermal energy, which has the knock-on effect of expanding the gas (kinetic energy) and the increase in pressure drives the reciprocating piston. after the gas is done driving the piston (BDC) most of its kinetic energy has been transferred into the mechanicals, but there is still tons of heat (thermal energy) left in the gas when it's exhausted out of the motor. this heat is worth about 3/4 of the energy we started with. it's very difficult to productively use this wasted heat, and it's unlikely there will be a usable thermo-electric device any time soon. currently the most practical way of harvesting energy from exhaust is a turbocharger (good for at least 10 hp worth of work, iirc) but even then it's using leftover kinetic energy and not the heat directly.

with conventional brakes, the kinetic energy of the car's mass is converted into heat by friction. if the speed is X, and you decelerate to 0, then damn near all of X has been turned into heat, with a tiny, tiny fraction turned into sound and maybe some visible wavelengths. this heat then leaves the system, so it will never power your car again. that's why conventional brakes are 100% wasteful.
 
The Boston Dangler said:
With conventional brakes, the kinetic energy of the car's mass is converted into heat by friction. if the speed is X, and you---> decelerate <---to 0, then damn near all of X has been turned into heat, with a tiny, tiny fraction turned into sound and maybe some visible wavelengths. this heat then leaves the system, so it will never power your car again. that's why conventional brakes are 100&#37; wasteful.
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ACCELERATE!!!!!!!!!!!

You cannot have negative acceleration, only positive acceleration in another vector.

rageface.jpg
 
bruceb said:
Agree. I want a car that both take a hit and give one if needed. Also to be able to get out of it's own and other car's way, if needed, in a big hurry. Hybrids can't do that. Small cars for me present too much potential for occupant injury and are not roomy enough inside.
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This. I am willing to sacrifice mpg for safety.
 
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