Question for you hypermilers. In my continuous attempt to figure out how to get my average mileage above the low-60s, I've noticed that it is nearly impossible to maintain any speed in any gear when the FCD is reading above 90 or so. In other words, if I'm driving 55mph on a flat highway in 5th gear and I put the car into lean burn around 100mpg or so, my speed will inevitably begin to taper off. That of course forces me to re-accelerate back up to cruise speed and repeat the process. If you plotted my speed vs time on any given road trip, it's a continuous roller-coaster of ups and downs trying to maintain speed. Does this seem normal or is there possibly something else to blame (tires not inflated enough, faulty systems, etc)?
Maintaining speed at 90+ mpg
1 - 4 of 4 Posts
Hi Mr. Rusttree; yes, the up and down roller coaster you speak of, is exactly the game and the challenge. The key is to REDUCE aero drag and rolling resistance, and any type of slowing force on the car. Try the tires ast 50 psi, and drive in a tailwind on the freeway at 53 mph. THAT will give you the feel of what you are trying to achieve. Then you have to manage forces over which you have no control; headwinds, inclines, cold temperatures, etc. Billy.....
G
Guest
·Hi Rusttree:
___Billy is right on … Press up those tires and do it now. I run anywhere from 52.5 - 60 #’s in mine and even though I give up some ride comfort (most anyone running 50 + #’s does
), the ICE’s load is at an absolute minimum when cruising down the highway. Given the speed limits in Arizona are high by comparison to us Illini in and around Chicago proper (55 vs. 70 mph, right?), you have a bit tougher situation. High pressure tires, low Kinematic Viscosity oil (0W-20 Mobil1 synthetic), and lower speeds are the key to leaving the EPA estimates in ruin
___The key to maintaining speed and hypermile FE in an Insight is to induce a continuous ballet of the accelerator through the lean-burn and NOx Purge events. When I hit a NOx purge, I back off the accelerator ever so slightly to maintain my target speed through the event and then when Lean-Burn hits again, just the slightest increase in accelerator pressure. In more detail, what I see in my Insight is a very slight sinusoidal action of the Instantaneous during a NOx purge event so I counterbalance the acceleration/slight deceleration/acceleration by easing up/stepping on her/and easing up again ever so gently. I use 3 directional adjustments with a continuous fluid adjustment in between through a NOx purge event if that makes sense to you. For Lean burn, just a gentle increase in accelerator angle and you are back to outrageous FE.
___If you are speaking of any sort of an incline, you want to literally coast up the slope (within reason as you aren’t going to coast up Pikes Peak) while bleeding off speed for potential. In other words, attempt to maintain the Instantaneous at a given target (100, 105, 110 …). On the back side of the slope, you want to maintain your target MPG but now you are increasing speed while trading off the earned potential for kinetic. An example … Let us say you are heading towards an overpass of ~ 30’ in height at 53 mph. You will maintain your Instantaneous at whatever target you are currently at but your speed will bleed down to lets say 49 mph at the crest. With the excess potential, you will accelerate down the backside of the overpass to 53 mph by the time you have reached the bottom. Now traffic around you might dictate a more standard cruise control type speed so you cannot always use the technique (“Driving w/ Load”) but when you can, use it. Another tip. Never use the pack except under emergency situations if you can help it. It might be neat to see the Assist bars light up as well as the feeling that the Insight has a nice kick but every time you use it, it is to the detriment of your overall FE. There is a small area in second gear during acceleration that is very hard to not use at least 4 bars but with some practice, it will become natural to see it, let off, and reaccelerate with no bars showing as you shift up into higher gears.
___After all is said and done; you will achieve much higher FE and place much less stress on the ICE and pack. The day time temperatures you are currently receiving are perfect for hypermiling as well.
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:1i4dc76a][email protected]nk.net[/email:1i4dc76a]
___Billy is right on … Press up those tires and do it now. I run anywhere from 52.5 - 60 #’s in mine and even though I give up some ride comfort (most anyone running 50 + #’s does
), the ICE’s load is at an absolute minimum when cruising down the highway. Given the speed limits in Arizona are high by comparison to us Illini in and around Chicago proper (55 vs. 70 mph, right?), you have a bit tougher situation. High pressure tires, low Kinematic Viscosity oil (0W-20 Mobil1 synthetic), and lower speeds are the key to leaving the EPA estimates in ruin ___The key to maintaining speed and hypermile FE in an Insight is to induce a continuous ballet of the accelerator through the lean-burn and NOx Purge events. When I hit a NOx purge, I back off the accelerator ever so slightly to maintain my target speed through the event and then when Lean-Burn hits again, just the slightest increase in accelerator pressure. In more detail, what I see in my Insight is a very slight sinusoidal action of the Instantaneous during a NOx purge event so I counterbalance the acceleration/slight deceleration/acceleration by easing up/stepping on her/and easing up again ever so gently. I use 3 directional adjustments with a continuous fluid adjustment in between through a NOx purge event if that makes sense to you. For Lean burn, just a gentle increase in accelerator angle and you are back to outrageous FE.
___If you are speaking of any sort of an incline, you want to literally coast up the slope (within reason as you aren’t going to coast up Pikes Peak
) while bleeding off speed for potential. In other words, attempt to maintain the Instantaneous at a given target (100, 105, 110 …). On the back side of the slope, you want to maintain your target MPG but now you are increasing speed while trading off the earned potential for kinetic. An example … Let us say you are heading towards an overpass of ~ 30’ in height at 53 mph. You will maintain your Instantaneous at whatever target you are currently at but your speed will bleed down to lets say 49 mph at the crest. With the excess potential, you will accelerate down the backside of the overpass to 53 mph by the time you have reached the bottom. Now traffic around you might dictate a more standard cruise control type speed so you cannot always use the technique (“Driving w/ Load”) but when you can, use it. Another tip. Never use the pack except under emergency situations if you can help it. It might be neat to see the Assist bars light up as well as the feeling that the Insight has a nice kick but every time you use it, it is to the detriment of your overall FE. There is a small area in second gear during acceleration that is very hard to not use at least 4 bars but with some practice, it will become natural to see it, let off, and reaccelerate with no bars showing as you shift up into higher gears.___After all is said and done; you will achieve much higher FE and place much less stress on the ICE and pack. The day time temperatures you are currently receiving are perfect for hypermiling as well.
___Good Luck
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:1i4dc76a][email protected]nk.net[/email:1i4dc76a]
Joined
·
766 Posts
Good tips so far.
Rusttree, consider that the road may not be as flat as you initially thought. I have found that a truly level road is a rare thing indeed; the instantaneous MPG readout is very good at letting you know when you've had to push the pedal down to maintain speed over an incline you wouldn't see with the naked eye.
Rusttree, consider that the road may not be as flat as you initially thought. I have found that a truly level road is a rare thing indeed; the instantaneous MPG readout is very good at letting you know when you've had to push the pedal down to maintain speed over an incline you wouldn't see with the naked eye.
1 - 4 of 4 Posts
