Coasting
#1
I have been riding my bike a lot lately and I came to think - I dont pedal all the time yet I move all the time - I can do the same in my car! On my way to work I have about 6 blocks where there is a stop sign - so what I di was to accellerate to 35 as usual and then put it in neutral and coast the rest of the block until I had to come to a stop. There are also other situations where I knew that I could safely coast (put it in neutral and roll). Using this I got about 4 MPGs more than on my last tank. I frequently find that I can maintain 35 MPH for up to 3 minutes in neutral - the coeficient of drag on the echo is really low.
I am wondering if any one has any input on this driving style? It is obviously not an entirely safe thing to do - since when the car is in neutral it is not under my control - if I have to accellerate away from something I have to put it in gear before hitting the gas.
However - I am wondering why car makers have not made a clutch that will allow "freewheeling" - like on a bicycle. I know that by having a direct connection between the engine and the wheels you allow for engine braking - but it also kills gas mileage. It should be possible to make a clutch that allows freewheeling when driving and engine braking when breaking - especially on the hybrid cars.
Let me know what you guys think.
I am wondering if any one has any input on this driving style? It is obviously not an entirely safe thing to do - since when the car is in neutral it is not under my control - if I have to accellerate away from something I have to put it in gear before hitting the gas.
However - I am wondering why car makers have not made a clutch that will allow "freewheeling" - like on a bicycle. I know that by having a direct connection between the engine and the wheels you allow for engine braking - but it also kills gas mileage. It should be possible to make a clutch that allows freewheeling when driving and engine braking when breaking - especially on the hybrid cars.
Let me know what you guys think.
#2
Hi Freak_lad:
___Most Hypermilers use various coasting techniques (ICE off/on - Regen/non-Regen - coasting into parking spaces, parking to take advantage of elevation for coasting from a start to some speed before starting the ICE) whenever and wherever possible. With a bit more time behind the wheel, you might actually make it to the Hypermiler list in your Echo if you do begin to find yourself in the 38 + mpg range tank over tank. As it stands, you own an inexpensive yet great car for high fuel economy indeed!
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
___Most Hypermilers use various coasting techniques (ICE off/on - Regen/non-Regen - coasting into parking spaces, parking to take advantage of elevation for coasting from a start to some speed before starting the ICE) whenever and wherever possible. With a bit more time behind the wheel, you might actually make it to the Hypermiler list in your Echo if you do begin to find yourself in the 38 + mpg range tank over tank. As it stands, you own an inexpensive yet great car for high fuel economy indeed!
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
#3
My Prius will coast sometimes. I try to find that for those short "almost at the traffic light" or "almost time to decellerate, but not quite yet" situations. I don't have to shift to acheive it, but I could if i wanted to, because my gear selector does have a "neutral" position.
I'm also not afraid to use electric-only, sometimes called "stealth," because even after depleting the battery some, the car always seems to recharge it rather quickly the next time I have to step on the accellerator for some reason (get up to new, faster speed limit, make a turn, stop and then re-go at a stop sign or traffic light, etcetera).
To repeat, I think of "gliding/coasting" as "free distance", and I think of "electric-only stealth" as "almost free."
I'm also not afraid to use electric-only, sometimes called "stealth," because even after depleting the battery some, the car always seems to recharge it rather quickly the next time I have to step on the accellerator for some reason (get up to new, faster speed limit, make a turn, stop and then re-go at a stop sign or traffic light, etcetera).
To repeat, I think of "gliding/coasting" as "free distance", and I think of "electric-only stealth" as "almost free."
#4
I do a lot of coasting to get my high MPG's. In the rolling, rural roads where I get my best mileage (since I don't have a lean burn ICE that gets its best on the flats) I can spend about half of my total driving time coasting the downhills. When coasting, I just press down on the clutch and hold it down while leaving the gearshift in gear until I need to apply power, then I just release the clutch while nudging the accelerator to match RPM's for a smooth engagement. This way there is no safety issue since I can apply power when needed in a fraction of a second. And with 356,000 miles on the transmission and with the original clutch, it obviously isn't hard on the gears. The only time I will coast in neutral with the clutch released is when I have a long (over a mile) downhill coast on a fairly straight road in a low traffic situation. Also do a lot of coasting in urban driving when approaching traffic congestion, lights, stops, etc. Basically I coast whenever I encounter a downhill section of road where my vehicle will maintain its speed and whenever I have to slow down for lower speed limits, traffic, traffic lights, stops, and curves. As much as possible I use coasting rather than braking (friction or compression) to reduce my speed when it needs to be lowered. While driving on familiar roads, I can use the speeds that my vehicle attains while coasting to determine the density altitude for that particular drive so I can get an idea of how good my MPG's will be for that day since I don't have a game gauge. Also an unusual drop in coasting performance will also alert me to a tire that has dropped in pressure.
#5
I'm not sure how to phrase this, but here goes.
When I am coming to a red light, I can ease off on the gas enough so the instantaneous mileage goes way up, but not enough for the battery to charge.
I suspect this is similar to coasting.
When I am coming to a red light, I can ease off on the gas enough so the instantaneous mileage goes way up, but not enough for the battery to charge.
I suspect this is similar to coasting.
#6
For a TDI, each time you are in gear and not touching the accelerator (the "diesel pedal"), the ECU cuts fueling.
I can see it on my MFA and VAG-COM.
The accelerator is not mechanical but drive by wire.
I don't know if the hybrids are drive by wire, but if they are, coasting in gear should be more economical than coasting in neutral.
I can see it on my MFA and VAG-COM.
The accelerator is not mechanical but drive by wire.
I don't know if the hybrids are drive by wire, but if they are, coasting in gear should be more economical than coasting in neutral.
#7
Originally posted by Rammstein@Aug 9th 2004 @ 5:41 PM
For a TDI, each time you are in gear and not touching the accelerator (the "diesel pedal"), the ECU cuts fueling. I can see it on my MFA and VAG-COM. The accelerator is not mechanical but drive by wire. I don't know if the hybrids are drive by wire, but if they are, coasting in gear should be more economical than coasting in neutral.
For a TDI, each time you are in gear and not touching the accelerator (the "diesel pedal"), the ECU cuts fueling. I can see it on my MFA and VAG-COM. The accelerator is not mechanical but drive by wire. I don't know if the hybrids are drive by wire, but if they are, coasting in gear should be more economical than coasting in neutral.
FYI.....Laterz...........
#9
Hi Rammstein:
___The HCH is a Honda Civic Hybrid. The only drive by wire Hybrid is the Prius.
___What was being discussed above was either Fuel cut (fuel shut off to one or more cylinders) for coasting with or without regen, straight regen without fuel cut in a coast, or a simple coast w/out fuel cut or regen. For maximum fuel economy, fuel cut w/out regen is the best mode to be in as long as your pack is at or near its maximum charge anyway and you have a long ways before you have to hit the binders if at all. The HCH has a more advanced fuel cut mode(s) then the Insight but I have since forgotten the details. I thought it was something like 3 of 4 cylinders have a fuel cut mode during regen or something similar IIRC? The Insight is either in coast w/ Fuel cut, coast w/ regen, or a pure coast but not a mixture of any of the three. I am not sure about the Insight’s CVT’s modes however. Clear as mud? I will have to look this up just to make sure as it has been some time since this topic has presented itself. Today’s Diesel’s always fuel cut when coasting unlike those of old but regen is a Hybrid trait all its own given the MG set(s) and Pack additions.
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
___The HCH is a Honda Civic Hybrid. The only drive by wire Hybrid is the Prius.
___What was being discussed above was either Fuel cut (fuel shut off to one or more cylinders) for coasting with or without regen, straight regen without fuel cut in a coast, or a simple coast w/out fuel cut or regen. For maximum fuel economy, fuel cut w/out regen is the best mode to be in as long as your pack is at or near its maximum charge anyway and you have a long ways before you have to hit the binders if at all. The HCH has a more advanced fuel cut mode(s) then the Insight but I have since forgotten the details. I thought it was something like 3 of 4 cylinders have a fuel cut mode during regen or something similar IIRC? The Insight is either in coast w/ Fuel cut, coast w/ regen, or a pure coast but not a mixture of any of the three. I am not sure about the Insight’s CVT’s modes however. Clear as mud? I will have to look this up just to make sure as it has been some time since this topic has presented itself. Today’s Diesel’s always fuel cut when coasting unlike those of old but regen is a Hybrid trait all its own given the MG set(s) and Pack additions.
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net