Good, bad, or neither for the car?
Insight seems to have lots of drag when descending hills & it's annoying having to press the pedal just to maintain speed. I assume the high drag has something to do with regen.
I tried shifting in neutral a couple times & the rpms jumped at first. Once I lost momentum I matched rpms & shifted into drive. Felt smooth.
Your right about giving partial petal to coast vs regen. I think I read it wasnt recommended to coast in nutral, then go back to drive while rolling and in some states its illegal to be in N while moving.
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Enginer 4 kilowatt PHEV, 3000k 35 watt fogs, Eco bulb highs, 4300k 35 watt low all w/relay kits, DRLs/Rear Wiper removed&rear interior gutted, Sony HU W/front speakers, Tanabe nf springs, 35% tint all around, all LED lamp replacement, 09 fit progress rear sway bar, OEM block heater, full gril block, KN Filter, Honda vent visiors, group 51 battery, home made balancer/grid charger Best/Worse MPG 96/36
Your right about giving partial petal to coast vs regen. I think I read it wasnt recommended to coast in nutral, then go back to drive while rolling and in some states its illegal to be in N while moving.
Well, if you go back and find that post I made a few months back where I performed several scientific tests on this, my tests definitely confirm what you are saying. The Insight still has more drag going down a hill even in "EV-MODE" where you the battery is actually giving some assist while the engine is in fuel cut mode, than it does just putting it in neutral. So it isn't regen causing the drag, it is the drivetrain. The Inisght may have less drag than a typical gas car, but it is still enough to slow the car down.
As for driving the car in neutral on a regular basis, I'm not sure. I do know that on a normal car with an automatic trans-axle, it is fine to coast in neutral as long as the engine is running because the engine will keep pumping fluid through the torque converter. However, with the CVT in the Insight, I am not sure..
As for it being illegal to coast in neutral, I put that right along side laws like it being against the law for consenting adults to perform certain acts of sex or copying some music from your friend.. Don't tell and we won't ask.
Oh, well then. Some incoherent put it on a Wiki site, it must be true that coasting is dangerous.
The argument is that you might need to apply power to the wheels for some mythical evasive maneuver, so the car should be in gear all of the time.
The problem is that the odds of needing to apply power for an evasive maneuver while coasting downhill are infinitesimal. You need to brake 99.999999999% of the time. I'll take those odds.
I coast in neutral in my manual transmission cars for miles at a time. I live in a mountainous area, and there a a lot of roads where the speed you attain coasting is very close to the speed limit. With that said, it most fuel injected vehicles, the fuel is cut off totally when coasting for long periods in high gear, so you might end up using less gas by leaving the car in gear, but only if you can maintain the speed limit in gear.
As for driving the car in neutral on a regular basis, I'm not sure. I do know that on a normal car with an automatic trans-axle, it is fine to coast in neutral as long as the engine is running because the engine will keep pumping fluid through the torque converter. However, with the CVT in the Insight, I am not sure..
It looks like it is a comparable setup. In the cut-away in the service manual the CVTF Pump is chain driven off of the input shaft. So as long as the engine is turning it would be pumping.
So if the CVTF pump is chain driven off of the input shaft then the Insight would require the drive wheels lifted when in tow, correct? I know this is typically the case for most automatics out there that they can't be towed due to lubrication issues and most manual transmission cars it doesn't matter when in neutral due to the oil bath that moving parts get to swim in.
...what about auto-stop? If the engine isn't turning does it just not get the lubricant pumping through while its off, or is this just a null issue with the no-torque low-speed operation?
Well, that is the interesting part. The CVT has a 'start clutch' that is the final connection to the drive train. If this is not engaged you 'could' tow with the front tires on the ground. The owner's manual goes through it on page 412. There is a 'special' procedure to reset the transmission to a tow-able state for up to 50 miles. The 'best' procedure is to raise the front tires.
As far as auto-stop, there would be no pumping if the engine isn't turning. Thinking about it, it has been asked 'why does an auto-stopped engine restart when shifting to park?". If you were in drive, gone into auto-stop and then switch into reverse on the way to park it might be restarting to supply hydraulics to reset the CVT for a possible change to reverse.
I cant advised someone to coast down a mountain in nutral. Plus in nutral you are burning gas, in D or S if no load it cuts fuel to the injectors. Just check the battery/gas pump screen.
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Enginer 4 kilowatt PHEV, 3000k 35 watt fogs, Eco bulb highs, 4300k 35 watt low all w/relay kits, DRLs/Rear Wiper removed&rear interior gutted, Sony HU W/front speakers, Tanabe nf springs, 35% tint all around, all LED lamp replacement, 09 fit progress rear sway bar, OEM block heater, full gril block, KN Filter, Honda vent visiors, group 51 battery, home made balancer/grid charger Best/Worse MPG 96/36
When gas went to $4 a gal. I started routinely shifting into "N" on long highway downgrades to get the better mpg in my Saturn SL. Only potential problem I could figure was damaging or misaligning the automatic transmission. Due to the potential mismatch of an engine at 700 odd rpm idle, and drive wheels spinning at 60 mph, and no clutch or AT mechanism to ease the engine up to an appropriate rpm. I solved this by noting engine rpm while cruising at 60mph. I'd move the gear shifter to "N" at the top of a hill. Use gentle braking, if needed, to control speed and alert to traffic conditions for any need of the engine. At the bottom of the hill I'd note the slow decline in speed and when approaching my "shift point", usually around 60 mph, I'd gently press the gas pedal. When the rpm approached the figure ususally used to maintain 60 mph in gear, I'd move the shifter back into "D". When shifting I occassionally noticed a little thud in the drivetrain, but when I got better at matching the rpm to speed at time of shift, no thud was detectable. Did this for 10-20,000 miles with no problems before selling the SL to get the Insight.
With the Insight's automatic fuel cut-off I'd guess I'm getting equal or better mpg benefit with less effort, and risk of mechanical problem, by just taking my foot off the gas pedal.
Currently I use long downgrades to either charge-up the IMA battery by moving foot from gas to brake pedal and just tap the brake pedal enough to move the gauge to high charge while not engaging the brake pads. Or I'll very lightly press the gas to get no arrows on the energy flow screen, or 90-100 mpg on the instant mpg slider screen while maintaining the battery assist / charge meter in exact middle neutral postion, for the "no drag" benefit of higher speed......or as "gravity power" as I like to think of it.
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2010 Insight EX-Nav Clear Sky Blue. Driving the Blue Bird since May 30, 2009
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coasting downhill in neutral
