Yeah, pretty close. Not sure how many feet but basically pull up close and back off until you feel a little "turbulence" for lack of a better word and the pull forward just a touch.
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Any hypermilers? And busting myths.
- Thread starter Let It Fall
- Start date
Yeah, pretty close. Not sure how many feet but basically pull up close and back off until you feel a little "turbulence" for lack of a better word and the pull forward just a touch.
kanonfodr said:
I agree with most everything you've said, but I'm gonna have to get you to explain that.
They're designed to go fast. simple as that. the engine runs at proper RPM's for the best economy in sixth at that speed.
The most significant change you can make is to run a user programmable ECU. You can set your own fuel and ignition maps and data-log on a laptop while driving to fine tune for economy and performance.
Stock ECU's maintain the Air/Fuel at 14.7:1 (lamda=1) because that's where the catalytic converter is the most efficient. But if you want to increase power when needed (wide open throttle) the best A/F ratio is richer (more fuel) while best fuel economy while cruising is lean (more air).
In the U.S., modifying your fuel and ignition maps in this manner is illegal on modern ECU controlled cars driven on the street because the most efficient pollution control is considered more important than the most efficient fuel economy.
Stock ECU's maintain the Air/Fuel at 14.7:1 (lamda=1) because that's where the catalytic converter is the most efficient. But if you want to increase power when needed (wide open throttle) the best A/F ratio is richer (more fuel) while best fuel economy while cruising is lean (more air).
In the U.S., modifying your fuel and ignition maps in this manner is illegal on modern ECU controlled cars driven on the street because the most efficient pollution control is considered more important than the most efficient fuel economy.
Jake Saint said:
I understand your premise(that engine 'X' operates most efficiently at RPM 'Y') which is true, but I'm still not buying your argument. I've heard this all before, and Wiki sums it up thusly:
"Increasing speed to 90 mph (145 km/h) from 65 mph (105 km/h) increases the power requirement by 2.6 times, the energy per unit distance by 1.9 times, and decreases fuel economy. In real world vehicles the change in fuel economy is less than the values quoted above due to complicating factors."
So lets call it 2x the power, and 1.5 times the energy/ unit distance. With these factors in mind it's hard to see how your premise can stand.
Too bad we can't get those cars here. Of course the oil companies would rather jack up our gas prices and then run commercials on TV blaming the government.
I think the problem stems from the fact that thermodynamic efficiency and fuel economy are not equivalent.
this is not factoring in things like aerodynamics, the amount of power generated, etc. So while, yes, accelerating to that speed requires 2.5 times the power, HOLDING that speed requires much less, in both power and fuel.
EricF said:
Your not trying to increase performance just try reading up on it. Google wai ecomodder
I don't understand why everyone thinks more power = better gas mileage?
From what I read the way a warm air intake is supposed to work is decreasing idle fuel usage. Scan gauge GPH readout shows this. And because the air is closer to combustion temps it's more efficient? Also wouldn't warm air ****** timing? Or advance it gah I can't remember.
From what I read the way a warm air intake is supposed to work is decreasing idle fuel usage. Scan gauge GPH readout shows this. And because the air is closer to combustion temps it's more efficient? Also wouldn't warm air ****** timing? Or advance it gah I can't remember.
L-A said:If fuel economy is paramount to someone, I don't get why a car sounds like a smart choice
Because so is safety, and making it to work if it rains And kids.
If fuel economy is paramount to someone, I don't get why a car sounds like a smart choice
No kidding. I live in the Boston area, and there's plenty of smug Prius drivers with vanity plates, bumper stickers, even home made signs taped to their windows highlighting how they are saving the planet. There's also abundant public transportation, which would welcome those hypocrites onboard.
I tried a lighter version of "hypermiling" for a tank...it worked, my mpg went up by 3-4 mpg, but in the end it's not worth it for me to drive like an a$$hole. I could just go buy a car that gets better mpg if it meant that much to me.
A couple of questions:
1. Is it possible to hypermile with an automatic transmission?
2. If I take my car out of gear (i.e., into neutral) going downhill, the rpm drops significantly. Are there any damaging effects of doing this? When I remember, I also put it in neutral at stoplights, and at long lights / traffic, turn the car off.
3. What kind of tire pressures do you recommend? I've heard that I should over-inflate my tires (more than design point, but less than burst pressure rating). My car specifies 31psi/tire, I've had decent success with 36 psi/tire. Any thoughts?
4. Other than modifications to the car (as OP mentioned), what are some practical driving tips to make the mpg go way up? I already avoid rapid starts & stops, always coast to a stoplight, never brake on the highway (unless needed due to the aggressive driving habits of ****offs).
5. What kind of HVAC settings?
Thanks!
ian
1. Is it possible to hypermile with an automatic transmission?
2. If I take my car out of gear (i.e., into neutral) going downhill, the rpm drops significantly. Are there any damaging effects of doing this? When I remember, I also put it in neutral at stoplights, and at long lights / traffic, turn the car off.
3. What kind of tire pressures do you recommend? I've heard that I should over-inflate my tires (more than design point, but less than burst pressure rating). My car specifies 31psi/tire, I've had decent success with 36 psi/tire. Any thoughts?
4. Other than modifications to the car (as OP mentioned), what are some practical driving tips to make the mpg go way up? I already avoid rapid starts & stops, always coast to a stoplight, never brake on the highway (unless needed due to the aggressive driving habits of ****offs).
5. What kind of HVAC settings?
Thanks!
ian
I live in Atlanta, and the public transportation here blows. It takes me about 40-45 minutes to get to work. If I was to take public transportation, it would be appoximately 3 HOURS to get to work.If fuel economy is paramount to someone, I don't get why a car sounds like a smart choice
Atlanta is a "sprawling city". Anywhere you need to go is at least 30 minutes away, and public transportation will not work for those that are outside the metro area and not near a major pkwy or highway. Add to the fact that each county has their own Bus system and only 2 counties actually have a train system. It sucks.
I have a 01 Nissan Pathfinder and I go through about 100-130 a week in gas.
Jake Saint said:
No, you've got it all wrong. This is ALL ABOUT aerodynamics, and the power/ energy required to maintain a given speed. Acceleration is not a factor here.
Every time you double your speed, say, from 50 to 100mph, the power required to maintain that speed quadruples.
Chebass88 said:
Yes, coasting on hills is acceptable and won't damage anything.
The other things you are doing help.
Over inflating tires is a bad idea, because it won't help mileage much if any, but it WILL cause the tires to wear rapidly in the centers.
Fitting the narrowest tires allowable on your wheels may help.
HVAC? A/C will reduce mileage. Running the heater will not.
According to data gathered by Myth busters, "Going less than 50mph it is more efficient to leave the windows down, but going greater than 50mph it is more efficient to use the A/C."
Chebass88 said:
1. Of course
2. It shouldn't damage transmission. Be aware of one thing those it's not always best to coast in neutral. Many newer cars kill the injectors when the vehicle is a. In gear b. no foot on accelerator c. Roma over a set point (1000 Rpms in my jetta). So basically the engine down shifts the cars inertia keeps the motor turning but there is no fuel being used. Sometimes you can coast in neutral if your coming to a stop and it's far. If you realize your stopping sooner than expected or going down a hill instead of using your breaks in neutral keep it in drive and let the engine break it.
3. Tire inflation can actually make a large difference. The common misconception about tire pressure is lower pressure makes the tire wider. It does only slightly, I only know this because I'm also an offroad enthusiast it greatly increases the lateral contact or length of the tire contact patch front to back. Never exceed the tire pressure on the tire. I usually inflate to 5psi below max.
4 read http://ecomodder.com/forum/EM-hypermiling-driving-tips-ecodriving.php
5. I believe in the list above it says and I sometimes do switch on a/c till the car gets cooler and then turn it off manually. Or don't use it at all and just leave the blower on with the a/c off or economy mode on. The way I understand it. The a/c is either on or off there's no I between. So if you think keeping the thermostat just a little cool helps it doesn't. A/c is fully 100% on and there is a blend door that blends the air to the temperature you want.
I appreciate anything that increases a vehicle's efficiency.
However I do NOT put fuel economy on a pedestal, as it is only one part of the total expense of owning/operating a vehicle SAFELY.
For example, an often discussed hypermiler technique of coasting downhill, in neutral, without using brakes, ignores the wear and tear on tires, which equals money, not to mention the questionable safety of "coasting" a vehicle out of gear.
To me, the TOTAL cost of operation is what counts.
Sure I like fuel economy, so I look for smaller cars (prefer wagons) with manual transmissions. My personal preferance is fuel injected models from the late '80s to early '90s, as IMO they have the best balance of economy, reliability, simplicity (I do basic maintenance and light repairs myself), and parts availability.
My current daily commuter vehicle is the perfect vehicle for me, since I often have to deal with snow covered mountains in the winter, I drive a 1991 Subaru Loyale wagon that is a 5 speed and 4 wheel drive.
I average 28 mpg all day long, and can coax 30+ mpg on long trips.
Sure, a few other cars can top it MPG wise and most cars are "faster", but most of them are not 4wd snow machines.
Oh, and I only paid $200 for my little Subaru. That leaves a lot of money left over for gas.
However I do NOT put fuel economy on a pedestal, as it is only one part of the total expense of owning/operating a vehicle SAFELY.
For example, an often discussed hypermiler technique of coasting downhill, in neutral, without using brakes, ignores the wear and tear on tires, which equals money, not to mention the questionable safety of "coasting" a vehicle out of gear.
To me, the TOTAL cost of operation is what counts.
Sure I like fuel economy, so I look for smaller cars (prefer wagons) with manual transmissions. My personal preferance is fuel injected models from the late '80s to early '90s, as IMO they have the best balance of economy, reliability, simplicity (I do basic maintenance and light repairs myself), and parts availability.
My current daily commuter vehicle is the perfect vehicle for me, since I often have to deal with snow covered mountains in the winter, I drive a 1991 Subaru Loyale wagon that is a 5 speed and 4 wheel drive.
I average 28 mpg all day long, and can coax 30+ mpg on long trips.
Sure, a few other cars can top it MPG wise and most cars are "faster", but most of them are not 4wd snow machines.
Oh, and I only paid $200 for my little Subaru. That leaves a lot of money left over for gas.
