Any hypermilers? And busting myths.

[Let It Fall]

Have been active in the hypermiling community for a while now and have learned a lot. While I'm not ready to replace my side mirrors with cameras and put pizza pans on my wheels I still love doing it/learning about it.

Here are a few tips that most people DON'T know

Warmer air is more efficient - hyper-milers often make warm air intakes coming off the exhaust manifolds this is because the air is less dense so the computer has to use less fuel to mix properly

Warner engines are more efficient- and people that put earlier opening thermostats are possibly running rich because the engine is too cold.

You could block the radiator for aerodynamics (greatly decreases drag) and not worry about over heating on most vehicles. A lot of people do this and while watching temperature on a digital readout engine stays cool even in moderate traffic

Underside of vehicle is one of the biggest areas that create drag

Accessories a/c alternator fan power steering use a lot of power. If I use my ac my mileage drops by a good 10mpg while cruising. I believe the amount of power used to turn the engaged compressor is substantial so much so that if you wanted to use an electric compressor it would require 3 phase ac. Also some guys do power steering deletes (can be easy and not needed on small vehicles) and even go as far as alternator deletes. The use multiple deep cycle batteries and charge them over night to run the injectors spark plugs and computer. Limited mileage though.

There is no optimum speed for all vehicles. Usually the most effecient speed is right when your torque converter locks up in the highest gear.

Cruise control isn't the normative efficient because it does the opposite of what is effecient on hills. Most effecient way to drive is hold a throttle position or similar. Basically allow the vehicle to slow down on climbs and speed up on descents.

I hate when when people say they get better mpgs going say 70 or 80 vs 55-60. This is nearly impossible as aerodynamic drag increases squared velocity.

Did you realize you use roughly 25% of the power your engine creates just to overcome aero drag at 50mph?

Tests have proven aerodynamics are more important than weight to a degree. A vehicle driving should spend more of its time driving rather than accelerating. It has been found aeromods were far more effecient than weight reduction.

Discuss?

 

[T-Bird]

Hi.

What's there to discuss?

People who are educated enough to be able to do the math, get it.

People who "fly by the seat of their pants" ... not that much.

IME anyway.

Regards
Sam

 

[DigMe]

I'm still not sure I know what a hypermiler is after reading your post but is it one of those people who drives too slow on the freeway?

bc

 

[Mark Reccord]

I'm still not sure I know what a hypermiler is after reading your post but is it one of those people who drives too slow on the freeway?

bc

Nah, they're the ones who drive too slow going uphill and too fast going downhill. While that might be better for fuel efficiency it's a hazardous way to drive, especially on busy highways.


I don't know if I buy the comment on AC causing a 10MPG difference. That seems pretty extreme to me. I suppose it varies from vehicle to vehicle, but I tested that in my car and found the difference was <2MPG with windows closed and <1 with them open.

 

[guroove]

IME, in city driving, the biggest mpg killer is your brakes. Routes with stop signs every block are the worst. Knowing traffic patterns and coasting to stops have increased my average mpg from 16-18 mpg a few years ago to a consistent 19-20 mpg that I get now.

 

[The Hawk]

Hypermilers are people who work very hard at squeezing out the most fuel efficiency from their vehicle that they can. And it's not just about coasting or a slight change on the car's exterior. These people "go the extra mile" (pun intended) to take a vehicle that is listed as say, 25MPG and squeeze more than DOUBLE that out of it.
Now-a-days, it's something to consider, when gas prices are going to hit an all-time high by mid summer.

 

[i_got_a_mohawk]

Hypermilers try to get the best mileage possible from their vehicle.

 

[Simo98]

Accessories a/c alternator fan power steering use a lot of power. If I use my ac my mileage drops by a good 10mpg while cruising. I believe the amount of power used to turn the engaged compressor is substantial so much so that if you wanted to use an electric compressor it would require 3 phase ac.

My question is, which will be more economical (in general): Driving with the air conditioner on, or driving with the windows down. I guess it would depend on what speed the vehicle is going..


Oh, a fairly simple one, but often overlooked. One of the most effective ways to increase your fuel economy is to use your brakes as little as possible. Every time you touch your brakes you're wasting energy, as you had to accelerate to that speed in the first place.

So take all corners as fast as possible!

Alternatively, just stop accelerating in order to slow down to the right speed by the time you hit the corner. If you drive the same roads often it's fairly easy to accomplish, I often do it, more for fun than anything. You'll get everywhere marginally slower I guess, but I'd be surprised if it made much of a difference. Besides, its safer imo, and should save you money on all sorts of things in the long run, not just fuel.

And yeah, use hills for free energy! Sort of. Probably a little on the reckless side though. I guess you can just tell the police you were trying to save the planet

 

[kanonfodr]

I'm still not sure I know what a hypermiler is after reading your post but is it one of those people who drives too slow on the freeway?

bc

Nah, they're the ones who drive too slow going uphill and too fast going downhill. While that might be better for fuel efficiency it's a hazardous way to drive, especially on busy highways.


I don't know if I buy the comment on AC causing a 10MPG difference. That seems pretty extreme to me. I suppose it varies from vehicle to vehicle, but I tested that in my car and found the difference was <2MPG with windows closed and <1 with them open.

Hypermilers are a buncha people pinching pennies at the risk of their lives, as well as the lives of others. Honestly are you feeling the difference (in your wallet) between 42.7 and 43 mpg??

Have been active in the hypermiling community for a while now and have learned a lot. While I'm not ready to replace my side mirrors with cameras and put pizza pans on my wheels I still love doing it/learning about it.

Here are a few tips that most people DON'T know

Or know better.

Warmer air is more efficient - hyper-milers often make warm air intakes coming off the exhaust manifolds this is because the air is less dense so the computer has to use less fuel to mix properly

Increasing the risk of lean pre-ignition if the engine is under load. The Stoichometric ratio of air to fuel is 14.7:1, rich is <14.6:1, lean is >14.8:1 . Modern vehicles have two O2 sensors to keep that ratio in check by analyzing your exhaust gas. All you're doing is robbing yourself of power because the ratio will almost always be the same.

Warner engines are more efficient- and people that put earlier opening thermostats are possibly running rich because the engine is too cold.

Pretty much true, so I use what the engineers who designed my vehicle said to use. Even if it is less than 5 bucks.

You could block the radiator for aerodynamics (greatly decreases drag) and not worry about over heating on most vehicles. A lot of people do this and while watching temperature on a digital readout engine stays cool even in moderate traffic

Possibly, provided you are hauling nothing more than groceries at sea level. Go up a few thousand feet and put some weight on that vehicle. Your engine will melt down. And remember that toy the thermostat we discussed earlier? If yours is failing then not having a blocked radiator could mean the difference between making it home to fix it or walking and getting picked up by a well-meaning axe murderer .

More importantly, where are the numbers? Can I get some drag co-efficients, verified MPG improvements, or quarter-mile times? Also, hybrids function differently than regular "sinner" cars so they don't run the risk of overheating as much sitting in traffic compared to my Jeep.

Underside of vehicle is one of the biggest areas that create drag

Truth. That's why, when you look at a Ferrari, they are smooth underneath

Accessories a/c alternator fan power steering use a lot of power. If I use my ac my mileage drops by a good 10mpg while cruising. I believe the amount of power used to turn the engaged compressor is substantial so much so that if you wanted to use an electric compressor it would require 3 phase ac. Also some guys do power steering deletes (can be easy and not needed on small vehicles) and even go as far as alternator deletes. The use multiple deep cycle batteries and charge them over night to run the injectors spark plugs and computer. Limited mileage though.

AC gives you a 10mpg drop? Dude, get a bigger hamster!! Never seen it affect any vehicle that much, including my parents 98 Mitsubishi Mirage with a 1.5liter engine. As far as power-steering deletes and alternator deletes: once again the unknowing sacrificing theirs and others' safety for pennies. Hope they got good insurance.

There is no optimum speed for all vehicles. Usually the most effecient speed is right when your torque converter locks up in the highest gear.

I eliminated the Torque Converter in my vehicles a few years ago, did wonders . And TC Lockup doesn't mean squat as far as your engine is concerned, and most efficient engine speed is always variable when you remember that you are on the road with hills, corners, and us other morons . Sometimes my most efficient engine speed is 3500 RPM because it suits the conditions, sometimes it's 1800 RPM (the happy spot on my 4.0L I6). Please consider all the variables when you drive.

Cruise control isn't the normative efficient because it does the opposite of what is effecient on hills. Most effecient way to drive is hold a throttle position or similar. Basically allow the vehicle to slow down on climbs and speed up on descents.

True, but Cruise Control is only there to give the operator (all these rumors earned you a demotion) a break on straight and flat. It's a reactive system, whereas a Driver can anticipate conditions. I do agree for the most part with the constant throttle thing, but keep conditions and other traffic in mind.

I hate when when people say they get better mpgs going say 70 or 80 vs 55-60. This is nearly impossible as aerodynamic drag increases squared velocity.

But is the engine working as hard? Gas mileage, simplistically, is fuel burned vs distance covered. a Corvette Z06 gets better gas mileage at 90 mph than it does at 60, and I had a Mazda pickup with a 4.0l V6 that did better (21.9mpg) on I-10 going no less than 75 (and reaching into the 90s occasionally) than it did on Highway 77 in Texas doing no more than 75 and spending most of it's time at 70-ish (20.5 mpg). A whole lot of factors including aerodynamics, powerband, and gearing come into play. You're physics are right, but they are only looking at it from one angle.

Did you realize you use roughly 25% of the power your engine creates just to overcome aero drag at 50mph?

See above.

Tests have proven aerodynamics are more important than weight to a degree. A vehicle driving should spend more of its time driving rather than accelerating. It has been found aeromods were far more effecient than weight reduction.

Discuss?

Aerodynamics are more important when your vehicle is at speed, but reducing unneccessary weight can help a bunch if you live in a place that has lots of stop and go traffic. Once again, consider the entire spectrum

For the record, one can go out and buy a 5-year-old Kawasaki Ninja 250 for less than 2 grand in great shape and get a steady 55+mpg for the next 15 years only needing general preventive and scheduled maintenance.

A 5 year old Prius will be 5-7 times that amount, get 45 mpg everywhere, and need the batteries (a caustic nickel type that is absolutely horrible for the environment) for the electric drive system replaced within the next 5 years, costing pretty much what the vehicle is worth at that point in time.

Peace,
Greg

 

[fdeck]

Drive less.

 

[Let It Fall]

I find the more fuel efficient your vehicle and the smaller the motor the more it robs.

If your driving a 6.0 truck no you won't see a difference if your hypermiling a 50mpg vehicle you will see a difference.

 

[Let It Fall]

My question is, which will be more economical (in general): Driving with the air conditioner on, or driving with the windows down. I guess it would depend on what speed the vehicle is going..

Oh, a fairly simple one, but often overlooked. One of the most effective ways to increase your fuel economy is to use your brakes as little as possible. Every time you touch your brakes you're wasting energy, as you had to accelerate to that speed in the first place.

So take all corners as fast as possible!

Alternatively, just stop accelerating in order to slow down to the right speed by the time you hit the corner. If you drive the same roads often it's fairly easy to accomplish, I often do it, more for fun than anything. You'll get everywhere marginally slower I guess, but I'd be surprised if it made much of a difference. Besides, its safer imo, and should save you money on all sorts of things in the long run, not just fuel.

And yeah, use hills for free energy! Sort of. Probably a little on the reckless side though. I guess you can just tell the police you were trying to save the planet

See when hyper mailing I drive in the early am and just as the sun is setting even in Louisiana you can be comfortable with the windows up and a/c off with tint.

The brakes thing is correct it's called DWB driving without breaks I didn't mention that because its super common sense.

 

[Marlat]

Get a small diesel car like a VW Polo Tdi Bluemotion and forget about all this stuff that endangers yourself and other drivers. Its 86mpg off the shelf and costs like £12,000.

 

[Let It Fall]

Hypermilers are a buncha people pinching pennies at the risk of their lives, as well as the lives of others. Honestly are you feeling the difference (in your wallet) between 42.7 and 43 mpg??

Or know better.

Increasing the risk of lean pre-ignition if the engine is under load. The Stoichometric ratio of air to fuel is 14.7:1, rich is <14.6:1, lean is >14.8:1 . Modern vehicles have two O2 sensors to keep that ratio in check by analyzing your exhaust gas. All you're doing is robbing yourself of power because the ratio will almost always be the same.

Pretty much true, so I use what the engineers who designed my vehicle said to use. Even if it is less than 5 bucks.

Possibly, provided you are hauling nothing more than groceries at sea level. Go up a few thousand feet and put some weight on that vehicle. Your engine will melt down. And remember that toy the thermostat we discussed earlier? If yours is failing then not having a blocked radiator could mean the difference between making it home to fix it or walking and getting picked up by a well-meaning axe murderer .

More importantly, where are the numbers? Can I get some drag co-efficients, verified MPG improvements, or quarter-mile times? Also, hybrids function differently than regular "sinner" cars so they don't run the risk of overheating as much sitting in traffic compared to my Jeep.

Truth. That's why, when you look at a Ferrari, they are smooth underneath

AC gives you a 10mpg drop? Dude, get a bigger hamster!! Never seen it affect any vehicle that much, including my parents 98 Mitsubishi Mirage with a 1.5liter engine. As far as power-steering

deletes and alternator deletes: once again the unknowing sacrificing theirs and others' safety for pennies. Hope they got good insurance.

I eliminated the Torque Converter in my vehicles a few years ago, did wonders . And TC Lockup doesn't mean squat as far as your engine is concerned, and most efficient engine speed is always variable when you remember that you are on the road with hills, corners, and us other morons . Sometimes my most efficient engine speed is 3500 RPM because it suits the conditions, sometimes it's 1800 RPM (the happy spot on my 4.0L I6). Please consider all the variables when you drive.

True, but Cruise Control is only there to give the operator (all these rumors earned you a demotion) a break on straight and flat. It's a reactive system, whereas a Driver can anticipate conditions. I do agree for the most part with the constant throttle thing, but keep conditions and other traffic in mind.

But is the engine working as hard? Gas mileage, simplistically, is fuel burned vs distance covered. a Corvette Z06 gets better gas mileage at 90 mph than it does at 60, and I had a Mazda pickup with a 4.0l V6 that did better (21.

9mpg) on I-10 going no less than 75 (and reaching into the 90s occasionally) than it did on Highway 77 in Texas doing no more than 75 and spending most of it's time at 70-ish (20.5 mpg). A whole lot of factors including aerodynamics, powerband, and gearing come into play. You're physics are right, but they are only looking at it from one angle.

See above.

Aerodynamics are more important when your vehicle is at speed, but reducing unneccessary weight can help a bunch if you live in a place that has lots of stop and go traffic. Once again, consider the entire spectrum

For the record, one can go out and buy a 5-year-old Kawasaki Ninja 250 for less than 2 grand in great shape and get a steady 55+mpg for the next 15 years only needing general preventive and scheduled maintenance.

A 5 year old Prius will be 5-7 times that amount, get 45 mpg everywhere, and need the batteries (a caustic nickel type that is absolutely horrible for the environment) for the electric drive system replaced within the next 5 years, costing pretty much what the vehicle is worth at that point in time.

Peace,
Greg

I avoid all dangerous driving styles I never block traffic or drive under speed limit with traffic.

I understand the mixture will always be the same that's why it works.

Less oxygen = less fuel for same mixture.

I drive a 2.0 turbo diesel no hybrids here sorry

Did you consider altitude wind traffic in your mpg difference?

I already drove a 250 for 8 months straight. A car offers safety room climate control and many other things do comparing them isn't equal. Also I averaged 45mpg with my 250 everytime. My car does better than that.

 

[Let It Fall]

Get a small diesel car like a VW Polo Tdi Bluemotion and forget about all this stuff that endangers yourself and other drivers. Its 86mpg off the shelf and costs like £12,000.

No it doesnt

 

[Marlat]

No it doesnt

Specs state between 67mpg (urban) and 90mpg (extra-urban) with a combined of 80.1mpg. And the cost is like £14,500 now (I was looking at 2010 pricing). If you are worried about millage its a far safer option than anything you are recommending.

 

[viper4000]

Specs state between 67mpg (urban) and 90mpg (extra-urban) with a combined of 80.1mpg. And the cost is like £14,500 now (I was looking at 2010 pricing). If you are worried about millage its a far safer option than anything you are recommending.

Edit: Do you mean Km/g? The specs seem kind of high.

 

[MonetBass]

If I use my ac my mileage drops by a good 10mpg while cruising.

Dang dude! I lose maybe 0.5 - 1 mpg when using my A/C. If your A/C is that much of a power drain, I'd have someone knowledgeable look at it.

 

[i_got_a_mohawk]

No it doesnt

Your right, it's 85.6 mpg

Not too unrealistic really, my parents have a Kia Ceed and get fairly consistent mileage just short of 70 mpg.

 

[Marlat]

Do you mean Km/H? The specs seem kind of high.

No, they are the MPG numbers the l/km figures are in the 3-4 range (which is the other accepted measurement. As I mentioned, with cards like the Bluemotion TDi Polo available there are much safer options other than poor driving habits / choices to get good economy out of a vehicle.