Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see May lease deals!
Options
Fuel Economy and Oil Dependency
This discussion has been closed.
Popular New Cars
Popular Used Sedans
Popular Used SUVs
Popular Used Pickup Trucks
Popular Used Hatchbacks
Popular Used Minivans
Popular Used Coupes
Popular Used Wagons
Comments
Might do that again. Had some very fine 4-cyl cars that were excellent, economical and fun to drive (responsibly). Last Satuday's WSJ had a test of the Honda Fit by their automotive writer/tester, Jeff Sabatini. After testing it, he asks if Fit is best car on the road at any price.
If Obama brings back 55, Fit would be fine for twisties as well as regular commuting for good gas mileage.
Well some people like Progress. We've progressed from the early 20th century with its 15mph SL's and basic cars. I would only assume that people want to get places faster as we continue to make planes, trains, and ferries faster. I do not see - going slower or staying the same desireable.
If people wanted to stay slow and really safe, they could all give up autos and walk, bike or ride a slow donkey.
Personally I'd like a vehicle that could dive like a sub, and fly - (remember that mini-sub on Voyage to the Bottom of the Sea?), and could drive around on land. Robbie the Robot could be the chauffeur on those times I wanted to entertain in Mile High Club lounge compartment.
I have no interest in being any sort of a Minimalist.
How is 55 a measure of responsibility when it is not embraced anywhere else, even in areas with safer roads than the US? How is a limit set so 40 year old semis could run with economy a measure of responsibility for people in 21st century cars? Competent modern cars like Acura TLs have no benefit at 55. I can average more than 10mph higher than that and get over 25mpg - in an E55!
There's no logic behind it.
Fine, if you're a flatlander, but what is needed to conquer the hills and mountains is much higher HP within a 60 mph speed limit.
As most high school graduates can not sight read concert level music, peole are not qualified to drive at speeds higher than 60.
The speed limit is dumbed down to the most average & mediocre ability and whinning for higher limits does not qualify you to be a better than average driver.
I find it endlessly amazing that drivers virtually everywhere else are trusted to exceed 60. Doesn't say much for the dying USA.
Per Wiki, US speed limits fall in line with most other countries, with the occasional exception like 50+% of the Autobahn. Speed limits by country
If an Orwellian nanny-state like England can have faster highways, why can't a land that basks in the claim of freedom and liberty?
I think 70-75 mph is a good fuel saving speed. 55 mph is asinine, beyond stupid. Even modern 4-cylinder cars can cruise at 80 mph serenely, safely and with power to spare.
Here is a web page with a number of graphs plotting MPH vs. MPG
55 was an almost arbitrary solution 35 years ago (see my earlier post regarding the origin of '55'). Surely we can do better than that now & keep traffic moving at pace.
Cheers!
Paul
Now I have a Mazdaspeed 6 - 6 speed with an engine that can produce about 4X the power. I can't even get into top gear at 55 mph on any sort of hilly environment, and the car is not geared that tall.
And here's the other thing - I'm happy with my mpg, if I wanted better mpg I wouldn't have bought the car I did and wanted to slow down. If I wanted better mpg I would have bought a car with higher mpg and still drove it faster than 55! :P
Some are not sold in North America, most are (Toyota Prius, Golf GTI, Golf TDi, BMW 535, MB 180 Kompressor and Geo Metro). And the ones which are are much more representative of what is on the road than a Mazdaspeed.
ALL curves show the same shape. Reason: wind resistance quadruples for each doubling of speed. To over come windresistance requires power, power comes from gasoline. A given curve may shift slightly to the right because of gearing but it will not change tha fact that the faster you go, the more fuel you will burn.
You have made a choice that you can and want to afford lower MPG, but that does not make it a good choice for everyone since it is not just about the fuel used but the pollution that is created when it is burned.
The vehicles listed in that report are OLD. I think one was from the 1980's! I listed my car not to say it is typical, but to say that if someone wants better mpg, then they can choose a higher mpg model - not having to worry about driving an archaic 55mph. I don't know where you live, but I can honestly say I haven't seen any of the cars you listed in months.
If you want to show graphs put up some real-world mpg ratings for the new 6-speed cars that are out - Malibu, Camry, 5-spd Corollas ...
Reason: wind resistance quadruples for each doubling of speed. To over come windresistance requires power, power comes from gasoline.
Yes but depending on what the number is, doubling it might not matter much. If you have 2% drag at 55mph and 3% at 65 mph then you haven't changed much. But if your cars gearing is 10% different between 5th and 6th gear then you end up with a net increase in fuel economy by going a speed in which you can stay in 6th gear.
If it was simply aerodynamic drag that affects mpg, then similarly you would expect mpg to continue to increase as you went slower ... 45, 35, 25, 15mph? does a 30mpg car at 55mph, get 60 mpg at 15mph?
So it is aerodynamics, gearing, engine rpms, weight, which all interact in the equation of what speed your car is going to run at to get optimum mpg. A 3-speed auto '75 Malibu and a 6-speed auto '09 malibu are not going to get optimum mpg at the same speed of 55mph.
Also I don't see where you are going with the pollution thing, as cars emit very little pollution. With the amount of pollution put in the air by all the other sources in the world, man-made and natural, 1 mpg makes no difference. If you want to stop pollution you may have an issue, since the goal of the world economy is to expand.
Population growth and world economic growth = increased waste products. I would like a world with less pollution, but it's not going to happen by me getting 35mpg or 20mpg, when there are billions of people striving to use more resources.
Yes, aero drag is not the only thing since we have multi speed vehicles, but generally speaking they will all be in top gear by 55 MPH on flat ground. So, if we make the assumption that a given vehicle is in top gear at 55, we then look at what it costs (in HP) to go faster. Take an average sedan with a Cd of .3, total rolling weight of 3750 Lbs and a total frontal area of 22 sq ft, we get HP losses to aero drag of:
55 MPH = 13 HP
65 MPH = 19 HP
75 MPH = 26.5 HP
85 MPH = 36.5 HP
Again, that horsepower must come from gasoline, you will burn more the faster you drive (once you are in top gear).
Polution: NHTSA states that there are about 3 trillion vehicle miles driven per year. If we simplify the numbers and say that on average the sum of all vehicles driven average 30MPG, the savings in gasoline by increasing that to 31 MPG would be about 3.2 Billion gallons. So would a 1 mpg increase make a difference? I'd say that it would.
Generally speaking, you would end up using more gas than at 65 since you would not be in the highest gear available. But the gas you'd save at 0 MPH...
I believe I know which you are referring to, but those are very small 4 cyl, and maybe diesel cars. They probably rev high, whuich is ineffficient. The U.S. mainly has large displacement low-revving engines at those same speeds. It is not compareable. I have had an '82 Escort which got lower mpg when pushed above 55-60mpg, I had an '88 Honda CrX which got 40mpg no matter what you did up to 70mph, and I had a 6-cyl. 5-speed '98 Camaro - the best mpg (35) I got on that was a 75mph trip on a highway.
I agree with you and the graph that most cars will start taking hits in mpg above 75-80mph. But that is the individual's choice as to how much fuel to use. Every individual can buy as much fuel as their pocketbook allows. Burn it in an RV, ride in circles in a large boat on a lake, or vacation around the world.
sum of all vehicles driven average 30MPG, the savings in gasoline by increasing that to 31 MPG would be about 3.2 Billion gallons. So would a 1 mpg increase make a difference? I'd say that it would
No it doesn't. Why? See above for other ways people will use the fuel.
Also if that oil is in the ground next year, it simply gets burnt next year, and turned into whatever pollution you worry about then. All the fuel eventually gets used! You can change the rate slightly yes, but not the end result.
I'll enjoy my fuel right now thank you, and let the people who are used to riding bike (around the world) stay on their bikes and not get into cars.
No. The gear size and the torque of the engine determine the lowest speed at which you can run without lugging the engine. So you can't take many cars which are geared to run at 2,000 rpm at 70mph in the top gear, leave the gears alone, and remap the shiftpoints, so that you're in 6th gear at 1,200rpm at 45-50mph.
My car which has a 4 cyl engine and should rev higher would be very unhappy in 6th gear at 45mph. I don't have to remap, I have a manual and I've tried it. The engine efficiency also is much better near the torque peak, which is another consideration, we discussed earlier. If you're running at low rpms the engine is operating inefficiently due to pumping losses.
The idea that speed limits have a proper place in our society is archaic at best.
It is no longer 1958, it is 2008, almost 2009, and speed limits should be abolished, and with all the savings in traffic enforcement, we could probably pay for all the research and development of alternative fuel sources ten-fold.
Traffic volume screams for regulation making the opinion of no speed limit egregious. :mad:
Most newer cars on the road today are under 4l displacement and would all rev under 2000 RPM at 60 MPH. The US still has high horsepower big blocks but they are not the norm. So the German graph is relevant to the US.
... I had a 6-cyl. 5-speed '98 Camaro - the best mpg (35) I got on that was a 75mph trip on a highway.
A single trip on 1 tank is not a valid MPG result. There could be environmental factors (strong tailwind, downhill) or human factors (not filling the tank as full as the previous time) that can skew the results. What was your MPG in the Camaro over the period of a year?
I agree with you and the graph that most cars will start taking hits in mpg above 75-80mph.
No, they start taking a hit shortly (RPM wise) after getting into top gear.
But that is the individual's choice as to how much fuel to use. Every individual can buy as much fuel as their pocketbook allows. Burn it in an RV, ride in circles in a large boat on a lake, or vacation around the world.
Yes it is a choice that people can make, but just because a person can make a choice does not miraculously make it a good choice.
... vehicles driven average 30MPG, the savings in gasoline by increasing that to 31 MPG would be about 3.2 Billion gallons. So would a 1 mpg increase make a difference? I'd say that it would
No it doesn't. Why? See above for other ways people will use the fuel.
Also if that oil is in the ground next year, it simply gets burnt next year, and turned into whatever pollution you worry about then. All the fuel eventually gets used! You can change the rate slightly yes, but not the end result.
Your logic is flawed here. You are saying that if I get a new car that will save a 100 gallons a year, that my neighbor will go out and do something to burn that 100 gallons that I am saving. I'd say that the amount of fuel burning activities will remain somewhat constant so what ever fuel consumption reduction is made will be a net reduction. And yes the fuel we save now will be burned in the future, but by spreading it out over a longer time frame there is less environmental damage.
OK then, remap the tranny, modify the transaxle/rear end...slow everyone down so the paranoid can have their way.
Most drivers aren't concerned, and for good reason. The extra safety, convenience and pleasure that comes from higher speeds on limited access highways are worth it. Speed limits should be set for safety, not to save gasoline.
We don't need to turn the state and local police into the energy police. How people use their gasoline is their business.
We've tried this approach in the 1970s and 1980s; it failed miserably; it's time to accept that and move on.
cdn_tch: Polution: NHTSA states that there are about 3 trillion vehicle miles driven per year. If we simplify the numbers and say that on average the sum of all vehicles driven average 30MPG, the savings in gasoline by increasing that to 31 MPG would be about 3.2 Billion gallons. So would a 1 mpg increase make a difference? I'd say that it would.
For new cars, volatile organic compounds (VOC) emissions drop as speed increases, while nitrogen oxides emissions are less at 70 mph then they are at 10 mph. For carbon monoxide emissions, speed increases emissions, but new cars are so clean that the increase is negligible.
For all three pollutants, the main problem is stop-and-go driving. That is what drives the big increase in emissions of those pollutants.
Slowing people down on limited access highways in the name of reducing emissions is a waste of time and a misapplication of law enforcement resources, especially given that the truly gross polluters are clunkers (almost 50 percent of vehicular pollution is emitted by about 10 percent of vehicles).
If you are really concerned about decreasing those pollutants, you would worry about improving and maintaining traffic flow, particularly in urban areas.
Also note that unregulated gasoline powered engines - used in lawn mowers, snowblowers, etc. - pollute much worse than automobile engines. A 1998 car, for example, would have to drive 305 miles to put out as much carbon monoxide as a snowblower operated for one hour. And a 2008 car is even cleaner than the 1998 model.
Sorry, but slowing people down in the name of pollution control is a waste of time, energy and money. Our air today is clean and getting cleaner, even with higher speeds, and will continue to do, even as people continue to drive at the safe, comfortable speeds of 75-80 mph.
I only took a couple of compareable long freeway journeys a year, so there is no comparision. Maybe 30mpg on my 2-lane 50mph 60-mile roundtrip commute of the time.
No, they start taking a hit shortly (RPM wise) after getting into top gear.
No. Do a little research on where gasoline engines run most efficiently. It is not necessarily at the lowest rpm.
Yes it is a choice that people can make, but just because a person can make a choice does not miraculously make it a good choice.
"Good" is subjective; it depends on your goal, which may not be the goal of your collective.
You are saying that if I get a new car that will save a 100 gallons a year, that my neighbor will go out and do something to burn that 100 gallons that I am saving.
Well if your conservation causes the cost of oil to drop, then that oil certainly becomes more tempting to use. Personal example - if oil is $4/gal I use electric and wood, if oil is $2.50 I burn the oil. Similarly people are driving a little more now then just a few months ago.
And yes the fuel we save now will be burned in the future, but by spreading it out over a longer time frame there is less environmental damage.
Bulloney. As an engineer, knowing quite a bit of physical chemistry and thermodynamics I can assure you, you end up with the same increase in entropy and the same by-products in the same quantities. You also must be ignoring the fact that with increasing populations, and a larger population globally using oil and gasoline, individual conservation does not stop consumption-growth. When you and the UN find a way to stop everyone in the world from using more let me know; and then maybe I'll consider using less too.
But on the other hand the reason I come to work everyday is so I can purchase the fuel I want to stay warm and to use anyway I want, whether you think it good or not. Someday I hope to own a Viper. :P
Leave earlier, drive safely, arrive with less tension having been endured. We all will be better citizens for it.
Why are those who advocate higher speeds the ones who are least qualified to handle those speeds? :confuse:
Most drivers aren't concerned because they don't think about it. They'll complain about how much it costs to fill their tank and then peel out of the gas station.
The extra safety, convenience and pleasure that comes from higher speeds on limited access highways are worth it.
Pleasure, yes, I'll agree with that; Convenience, doubtful; Extra safety, no, speed increases risk.
Speed limits should be set for safety, not to save gasoline.
It isn't an either or, it could be both.
For new cars, volatile organic compounds (VOC) emissions drop as speed increases, while nitrogen oxides emissions are less at 70 mph then they are at 10 mph.
Comparing 10 mph to 70 mph in this discussion is irrelevant. What are the stats on 60 vs 70 vs 80 mph? Also where is the information from? Please provide a link so we can all learn.
For carbon monoxide emissions, speed increases emissions, but new cars are so clean that the increase is negligible.
With 3 Trillion vehicle miles driven, the increase ends up being substantial.
Also note that unregulated gasoline powered engines - used in lawn mowers, snowblowers, etc. - pollute much worse than automobile engines. A 1998 car, for example, would have to drive 305 miles to put out as much carbon monoxide as a snowblower operated for one hour. And a 2008 car is even cleaner than the 1998 model.
Yes, unregulated gasoline powered engines do pollute more but that does not make it OK to pollute more with a car.
Sorry, but slowing people down in the name of pollution control is a waste of time, energy and money.
I have not advocated slowing down for pollution control. I just made the point that if we slow down, not only do we increase safety, but reduce emissions as well.
But please stay in the right lane so those of us that choose to can do so safely & enjoy it more.
Cheers!
Paul
Why are so many other developed nations able to handle 75-80, but not Americans?
Why are those who preach freedom and liberty the ones who become pseudo-authoritarians when it comes to speed limits, and why do said people who completely lack credentials believe they can judge driving ability? :lemon:
And those numerous nations are..............
Why are those who preach freedom and liberty the ones who become pseudo-authoritarians when it comes to speed limits, and why do said people who completely lack credentials believe they can judge driving ability?
Experience under all conditions enable discernment of selfish driving styles.
Yes on a multilane interstate, driving at 75-80 mph is the same skill level as driving at 55-60mph. You point the car straight, with slight turns of the wheel. Interstate driving is actually the safest and easiest, you'll find.
And for those that say people can't do that, in my neck of the woods - NorthEast - that is what people are driving on the interstates now. All I want is to make the current driving legal.
Turkey, and Zimbabwe. And even the psychotic Orwellian nanny state of Great Britain has a 70mph limit, which is an insane speed in the eyes of some here.
Experience under all conditions can also discern when some favor a speed which is simply illogical and regressive.
75-80 is a reasonable speed limit even for people that are older than the speed limit. For most people, the interstate/freeway/highway maximum speed limit should be 85.
Slowing down does not make anything safer. Slowing down does not reduce your risk of getting into an accident. However, if you do get into an accident, reducing your speed will lessen the severity of that accident. So by that logic, we should design our airplanes to fly 55 MPH in the air so that if there is a bad landing or takeoff people won't die?
Alternatively, we could just train our car and truck drivers as well as pilots are trained.
Train our drivers to a standard that makes interstate driving 'at speed' a non-event. No pass, no drive. Raise the bar.
Cheers!
Paul
The driver's tests in CA are a joke.
It is rude to expect others to get out of your way by keeping right of where you want to go agressively.
Rudeness is the weak man's imitation of strength. - Eric Hoffer
I guess this is where we differ on what is 'safe'.
Your definition is being able to follow the road at speed and not drive into the ditch.
My definition is that both the car and driver are capable of handling the speed when something goes wrong. Yes just about any imbecile can point a car in a straight line and do 80+ mph. Unfortunately there are precious few who have a feeling for the car they are in and would slow down if they had a sense that the car was losing downforce and starting to create lift, or realize that should a deer or other wildlife come up on the roadway how to best avoid a serious accident.
Airline pilots are trained in many worst case scenarios so they have the ability to get out of trouble. Airplanes are also certified for speed, and cars should be as well, not just how fast can it go, but rather how fast can it go with in its design specs (brakes, handling, aerodynamics).
i started using the program Safeway and its sister sites (vons, genuardis, dominicks) have created. Every time you use your Safeway card, you earn gas rewards! Im not a huge shopper but even the smallest rewards helped me out !
Has anyone tried this?
if so, how much did you save???
oh yeah, btw they have a site where you enter your zip to see if the store near you is participating!!!
It is rude to impede the progress of others driving a completely reasonable speed, and insane to believe you have the means to do so. Keep your tired old sled in the right lane and let the people of today go past - this is where your recourse ends. The slow and backwards will keep right or wish they had.
Therefore, increasing speed limits does not automatically mean the speed of traffic will increase.
You're kidding right? Please post a link - like Consumer reports stating vehicles are having hazardous lift at 80mph.
It's about 1,000,000 times more likely that someone will have a problem controlling their car on ice or snow then just driving down the road at 80mph. If you were going to put ay effort into improving people's driving skills, it would be on snow and ice.
or realize that should a deer or other wildlife come up on the roadway how to best avoid a serious accident.
I've known somebody that had a deer run into the side of the car, and my boss who hit one at 45mph and had no time to react. Deer are unpredictable, stupid and fast, which makes driving skills rather irrelevant. The stability control and ABS of vehicles allow drivers to maintain control in those cases where some avoidance maneuver is possible. Those systems act faster and better than any human can, and no great skill is needed; but the deer might move the same way you go.
Airline pilots are trained in many worst case scenarios so they have the ability to get out of trouble.
Are you inferring that many years of driving experience counts for nothing?
Airplanes are also certified for speed, and cars should be as well,
Airplanes and cars are designed and tested in much the same way. Most auto manufacturers have testing facilities, and cars designed for high speeds are tested for high speeds. Sports cars carry larger, more powerful brakes, and many cars now are equipped with certified H, V, or Z tires. I have no qualms that my Mazda couldn't run safely at full speed if on an appropriate Autobahn or track.