Your HCH driving technique
#61
05-24-2004, 02:59 PM
You're suggesting even on the highway it's better to use your foot? What strategy can you possibly use?
On another note...
MPG != MPH
MPG does not equal MPH
Miles Per Gallon does not equal Miles Per Hour
"I turned both my trip meters off and hopped onto the freeway and set the cruise control at the speed limit of 70MPG."
Don't you hate when you do that?
On another note...
MPG != MPH
MPG does not equal MPH
Miles Per Gallon does not equal Miles Per Hour
"I turned both my trip meters off and hopped onto the freeway and set the cruise control at the speed limit of 70MPG."
Don't you hate when you do that?
#62
05-24-2004, 04:31 PM
Join Date: Mar 2004
Location: Atlanta, Ga
Posts: 1,797
Thanks Jason I fixed that MPH-MPG error.
GreenHybrid driving strategy article
I'll be as brief as possible (Yea right)
As we know Cruise control keeps a very constant speed up & down hills.
As a result of this you have to burn extra fuel when climbing to maintain speed.
The fuel saved on the decline does not add up to the fuel burned.
Think about the HotWheels track you may have played with when a kid.
Put some "humps" into the track for hills and roll a marble down it.
The marble is not burning any fuel, it's only using what you have given it.
Observe its behavior as it rolls over the hills.
It will slow down on the incline and speed up on the decline.
Some kind of external fuel would be required to keep a constant speed up the hill to overcome gravity.
This is the problem with Cruise Control.
If you let gravity on the hills slow you down instead of burning all of it off in extra fuel,
you can regain more of the energy as gravity on the way down.
If your HotWhells marble could "burn" a tiny bit of fuel on the track flat spots
it would keep on going.
It takes significantly less fuel to maintain speed on the flat than doing so on a hill.
When is cruise control beneficial?
If one is in the habbit of excellerating up a hills or not keeping momentum on flat areas then CC would be beneficial.
Yea I sure do. Too much of this and at the end of my tank I won't be able to "Pass go or collect my 200 dollars" 
Steve
You're suggesting even on the highway it's better to use your foot? What strategy can you possibly use?
I'll be as brief as possible (Yea right)
As we know Cruise control keeps a very constant speed up & down hills.
As a result of this you have to burn extra fuel when climbing to maintain speed.
The fuel saved on the decline does not add up to the fuel burned.
Think about the HotWheels track you may have played with when a kid.
Put some "humps" into the track for hills and roll a marble down it.
The marble is not burning any fuel, it's only using what you have given it.
Observe its behavior as it rolls over the hills.
It will slow down on the incline and speed up on the decline.
Some kind of external fuel would be required to keep a constant speed up the hill to overcome gravity.
This is the problem with Cruise Control.
If you let gravity on the hills slow you down instead of burning all of it off in extra fuel,
you can regain more of the energy as gravity on the way down.
If your HotWhells marble could "burn" a tiny bit of fuel on the track flat spots
it would keep on going.
It takes significantly less fuel to maintain speed on the flat than doing so on a hill.
When is cruise control beneficial?
If one is in the habbit of excellerating up a hills or not keeping momentum on flat areas then CC would be beneficial.
Don't you hate when you do that?
Steve
#64
05-24-2004, 07:19 PM
Hi Jason:
___What Hot_Georgia_2004 is speaking of is what “Driving with Load” is all about. It does work and it doesn’t matter if the highways are full of circus performers or the entire roadway is a circus. I use it through Chicago’s Interstate/tollway system all the time with great effect and you can imagine the lunacy I see on a daily basis just trying to stay at the speed limit. You really don’t want to pass on this technique as it only costs you seconds per hill/overpass/bridge vs. minutes by driving the limits and will give you maybe another 5 - 10% increase in fuel economy depending on the hills you ascend and descend on your own daily commute or long drive. You really need to learn this technique and learn it well because it saves fuel like you wouldn’t imagine!
___And a note to all in terms of cruise control … It will hammer your fuel economy if you are on it all the time since the “Drive with Load” technique is essentially thrown out the window. If you keep throwing away the tools in the tool box, eventually you run out of tools to use and will more then likely receive what every one else does in terms of fuel economy. In other words, less then even the lowly EPA estimates! With larger vehicles with strong ICE’s, you can sometimes use cruise w/ its ACC and DEC to simulate a “Drive with Load” technique over hills and still receive fantastic mileage. In other words, you use your DEC buttons to simulate the natural loss of kinetic energy as you gain potential on the upward ascent of the hill and the ACC button to simulate the gain in kinetic with the loss of Potential on the down slope. I can use cruise in the Corolla and MDX for some of the smaller hills but once there is let say a 50’ - 75’ rise over a ¼ - 1/2 mile distance, the DEC method falls apart as it is not fine enough control. It helps if your cruise is rather insensitive to a single ACC/DEC input. The MDX is a bit touchy since when you hit it, it wants to dump 1 mph or add 1 mph right now. The Corolla is a bit more forgiving but you still have to be very careful when trying to use cruise while maximizing your fuel economy using a “Drive with Load” technique. The reason is that 1 screw up per hill will lower your overall fuel economy vs. just letting the ICE spin up, idle back, and then settle down again at the previous RPM while on cruise at a constant speed. For those with some fatigue in their accelerator foot, you can simply try to use cruise on the absolute flats and drop out completely for the rising and falling slopes, hills, over passes, bridges, whatever you come upon. It isn’t perfect but it will give you 50 - 75% of the drive with load technique gain in a smaller ICE equipped automobile without the constant inputs needed for the hyper milers. Rick Reese’s throttle strap simply locks the accelerator angle at a given position for a true “Drive with Load” setup so there is that option as well …
___I do use the “Drive with Load” technique with the cruise control in the MDX when traveling any lengthy distance including cross country and it works with great effect but as I said above, you had better practice and get proficient fast or you may as well not use it at all … Here is an example of that exact practice in our 4,500 # 4WD Lux SUV just 2 short weeks ago while going to pick up some of my sons stuff from his apartment at the University of Illinois. If it were just a bit warmer, 35 mpg would have been breached as I was at 34.7 mpg at 110 miles out when I hit the first of 2 cold fronts
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
___What Hot_Georgia_2004 is speaking of is what “Driving with Load” is all about. It does work and it doesn’t matter if the highways are full of circus performers or the entire roadway is a circus. I use it through Chicago’s Interstate/tollway system all the time with great effect and you can imagine the lunacy I see on a daily basis just trying to stay at the speed limit. You really don’t want to pass on this technique as it only costs you seconds per hill/overpass/bridge vs. minutes by driving the limits and will give you maybe another 5 - 10% increase in fuel economy depending on the hills you ascend and descend on your own daily commute or long drive. You really need to learn this technique and learn it well because it saves fuel like you wouldn’t imagine!
___And a note to all in terms of cruise control … It will hammer your fuel economy if you are on it all the time since the “Drive with Load” technique is essentially thrown out the window. If you keep throwing away the tools in the tool box, eventually you run out of tools to use and will more then likely receive what every one else does in terms of fuel economy. In other words, less then even the lowly EPA estimates! With larger vehicles with strong ICE’s, you can sometimes use cruise w/ its ACC and DEC to simulate a “Drive with Load” technique over hills and still receive fantastic mileage. In other words, you use your DEC buttons to simulate the natural loss of kinetic energy as you gain potential on the upward ascent of the hill and the ACC button to simulate the gain in kinetic with the loss of Potential on the down slope. I can use cruise in the Corolla and MDX for some of the smaller hills but once there is let say a 50’ - 75’ rise over a ¼ - 1/2 mile distance, the DEC method falls apart as it is not fine enough control. It helps if your cruise is rather insensitive to a single ACC/DEC input. The MDX is a bit touchy since when you hit it, it wants to dump 1 mph or add 1 mph right now. The Corolla is a bit more forgiving but you still have to be very careful when trying to use cruise while maximizing your fuel economy using a “Drive with Load” technique. The reason is that 1 screw up per hill will lower your overall fuel economy vs. just letting the ICE spin up, idle back, and then settle down again at the previous RPM while on cruise at a constant speed. For those with some fatigue in their accelerator foot, you can simply try to use cruise on the absolute flats and drop out completely for the rising and falling slopes, hills, over passes, bridges, whatever you come upon. It isn’t perfect but it will give you 50 - 75% of the drive with load technique gain in a smaller ICE equipped automobile without the constant inputs needed for the hyper milers. Rick Reese’s throttle strap simply locks the accelerator angle at a given position for a true “Drive with Load” setup so there is that option as well …
___I do use the “Drive with Load” technique with the cruise control in the MDX when traveling any lengthy distance including cross country and it works with great effect but as I said above, you had better practice and get proficient fast or you may as well not use it at all … Here is an example of that exact practice in our 4,500 # 4WD Lux SUV just 2 short weeks ago while going to pick up some of my sons stuff from his apartment at the University of Illinois. If it were just a bit warmer, 35 mpg would have been breached as I was at 34.7 mpg at 110 miles out when I hit the first of 2 cold fronts
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
#65
05-25-2004, 05:57 AM
Pretty Darn Active Enthusiast
Join Date: Apr 2004
Location: League City, Texas
Posts: 387
I have to say that while I am getting an avg. of over 50 mpg I am satisfied. Actually something like 52 mpg. I drive usually 60 miles one way to work and I use the cruise, it's there, I paid for it, I like it! The milage I am getting is more than twice what I was getting with my Toyota truck and I just filled up my wifes Tahoe (please forgive me ) and she gets like 13 mpg in the city. She only has to fill up once a month but still it's crappy. Never AGAIN..lol. Now for something to think about... have you seen miliage differ with the type of pavement you are on? I drive over a vast array of surfaces and it seems to me that some give better FCD readings than others. I have one place where the blacktop is quite rough not potholes just rough like stones sticking up slightly, and my bar goes down to like 45 from 55-60. On the other hand areas that are smooth concrete the milage goes WAY up. Put rain in the picture and throw everything out the window. Just wondering if anyone else has seen this or is this my mind playing tricks on me for working shift work...lol . Kevin
#66
05-25-2004, 07:10 AM
Hi Texashchman:
___You aren’t missing a thing in regards to both rain and/or pavement type. I see the best instantaneous on hard and smooth concrete as well. Rough and hot asphalt I see a small overall drop but it is hard to measure as it seems I lose “a few” mpg but I don’t have a real number because it is so slight. Rain can drop an Insight off by 10 - 30 mpg depending on how hard it is raining so that is a condition I would love to avoid. Unfortunately, Mother Nature doesn’t really care if we are trying to maximize fuel economy, does she
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
___You aren’t missing a thing in regards to both rain and/or pavement type. I see the best instantaneous on hard and smooth concrete as well. Rough and hot asphalt I see a small overall drop but it is hard to measure as it seems I lose “a few” mpg but I don’t have a real number because it is so slight. Rain can drop an Insight off by 10 - 30 mpg depending on how hard it is raining so that is a condition I would love to avoid. Unfortunately, Mother Nature doesn’t really care if we are trying to maximize fuel economy, does she
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
#68
06-06-2004, 01:35 PM
Buzz and Jinno,
I highly doubt that Steve is going into lean burn during these "hick-ups" going up hill. Lean burn is a condition wear the air to fuel ratio (by weight) goes from 14:1 to 22:1. This greatly lowers power and fuel consumption. There is a lean burn "window" that is effected byengine load, temp., and a few other criteria.
Cheers,
Steven
I highly doubt that Steve is going into lean burn during these "hick-ups" going up hill. Lean burn is a condition wear the air to fuel ratio (by weight) goes from 14:1 to 22:1. This greatly lowers power and fuel consumption. There is a lean burn "window" that is effected byengine load, temp., and a few other criteria.
Cheers,
Steven
#69
06-07-2004, 05:22 AM
Steven,
Why not? I can't think of any other condition where the car goes from getting higher mpg on the FCD with assist to no assist and lower FCD in an instant without changing pressure on the accelerator.
This happens in my 5 speed all the time, particularly when I start up a hill. The assist will kick in at first, trying to keep (what I believe, anyway) the car in lean-burn mode (as it was before I hit the hill), and will continue to do so until I hit the accelerator harder, or the car needs to purge the NOx from the system. Then it'll kick to gas only, with no assist.
Wouldn't you think this is what Steve is seeing on his hill, just a lower mpg value with a CVT? Seems logical to me, but I'm certainly open for suggestions. I've been wrong before!
Mark
Why not? I can't think of any other condition where the car goes from getting higher mpg on the FCD with assist to no assist and lower FCD in an instant without changing pressure on the accelerator.
This happens in my 5 speed all the time, particularly when I start up a hill. The assist will kick in at first, trying to keep (what I believe, anyway) the car in lean-burn mode (as it was before I hit the hill), and will continue to do so until I hit the accelerator harder, or the car needs to purge the NOx from the system. Then it'll kick to gas only, with no assist.
Wouldn't you think this is what Steve is seeing on his hill, just a lower mpg value with a CVT? Seems logical to me, but I'm certainly open for suggestions. I've been wrong before!
Mark
#70
06-07-2004, 07:34 AM
Join Date: Mar 2004
Location: Atlanta, Ga
Posts: 1,797
Since there is no positive indication (IE Light etc) I can only guess that lean burn begins around 50-60MPG. Anyone else have an idea on this?
If you are traveling down a flat section of road holding your foot on a specific point to get ~80MPG, and you hold your foot in the exact same place as you climb the hill and get ~60MPG on the crest (Trade off is reduced speed), with the figures above the car is in lean burn.
Since your foot is still in the exact same place as the previous flat road added with gravity you gain speed again on the downturn side.
If you are traveling down a flat section of road holding your foot on a specific point to get ~80MPG, and you hold your foot in the exact same place as you climb the hill and get ~60MPG on the crest (Trade off is reduced speed), with the figures above the car is in lean burn.
Since your foot is still in the exact same place as the previous flat road added with gravity you gain speed again on the downturn side.
