[Ecky]

Originally Posted by mpg_numbers_guy

Correct me if I'm wrong, but the Insight's most efficient speed seems to be 47-52 MPH, where I can consistently get at least 105 MPG on flat, windless cruising, and 45-55 MPH where I can consistently get at least 95 MPG on flat, windless cruising. That's with the lower grille block, but missing aero panels (will be ordering Scott's belly pan).

This reflects my experience. 55mph is without a doubt worse than 50. I've found that I can get 100+ while cruising at lower speeds, but it seems like head-winds, hills, and things which interrupt steady-speed cruising affect the car more at lower speeds.

Originally Posted by mpg_numbers_guy

Upshifting at 2200-2500 RPMs seems to yield better fuel economy than taking longer to accelerate by upshifting at 1800-2100 RPMs. In other words, I got about 25 MPG higher from upshifting at 2200-2500 RPMs and driving at 50 MPH than from upshifting at 1800-2100 RPMs and driving 35-40 MPH. It's also easier to maintain a constant throttle position at 50 MPH than 40 MPH and under. Maybe I don't need cruise control.

Those shifting points do not reflect my experience. I find shifting below 2250 delivers the best numbers, but our driving conditions may be different and you almost certainly have newer computers than are in my car. However I do find it easier to maintain throttle at 50 than at lower speeds

Originally Posted by mpg_numbers_guy

Drove the Insight for exactly 70 miles today. After the first 10 miles the IMA light came on, and stayed on after clearing it 3-4 times. Not getting any assist, regen, or autostop as expected.

Driving without the IMA isn't as bad as everyone seems to make it out to be. I just shift at 2500-3000 RPMs instead of 2000-2500 RPMs. My MPG is the same. Averaged 69.3 MPG over all 70 miles, which is pretty normal. Tank is at around 65 MPG (this includes my fast driving and braking to clean the lot rot).

Sounds like you had a catastrophic cell failure - one of them died in a way that could short out the pack, so it disconnected it entirely. Many packs die very gradually instead. Sorry to hear it happened.

Good fuel economy though, considering the conditions!

Originally Posted by mpg_numbers_guy

So, I will be bypassing the IMA as soon as possible. I am already offered $500 for the battery core by a company to be refurbished, which I will go with unless one of you guys wants it for $600 or whatever. The IMA light just came on and it probably could be grid charged easily back to full health, but I just don't have the time for it, nor do I care to invest the money into a decent grid charger. I was already planning on bypassing the battery when it began dying. Bypassing the battery will let me:

• Lower the floor for more storage space like Ecky did
• Remove about 100lbs (?) of weight from the car
• Possibly install Scott's rear springs, modified to lower the car back to it's original height from it being raised due to the hybrid battery being removed
• Drive the car anytime without worrying about a hybrid battery condition
• Have more fun driving the car -- actually, yes. Throwing the car in neutral and coasting to a stop is less tedious than downshifting through the gears to regen, and I don't have to constantly worry about keeping the hybrid battery charged enough to prevent forced regen. I had more fun hypermiling the car like a normal car and still getting phenomenal fuel economy. No more back-of-the-mind worrying about the hybrid battery condition.
• Recover some of the money spent on the car. Selling the battery core for $500 will make the overall price of the car $1000 instead of $1500.

Bypassing the battery will save me the effort required to wire up 1) regen button, 2) FAS button, and 3) IMA calpod clutch button mods. Instead I will "just" have to wire up a kill switch.

...but does the Insight still track distance/fuel economy with a kill switch???

I doubt a grid charger would bring it back based on how it went. You could probably pull it apart and try to find the cell that died, but this isn't a long term solution - any replacement cell would likely get out of balance more easily and would need to be balanced regularly.

Nice to hear you're getting as much for your failed battery! That's a very nice car you have for $1,000. Since you don't live in such a mountainous region you may not see any hit at all without the battery.

I think the car handles better without it personally, and you may not need Scott's rear springs since simply removing all that weight from the back will stiffen the rear up somewhat. You'll need to cut the rear springs a little if you want to keep the same ride height in the back. If you ever decide to go with a new pack or make the car a plug-in hybrid with a small lithium pack (150+++ mpg) I still have my uncut original springs which you're welcome to, and they're quite easy to put in.

And yes, the car will still accurately track economy with a kill switch, it's only if you key-off to turn the engine off that you'll get inaccurate numbers.

Originally Posted by mpg_numbers_guy

Did a little research, and apparently I can bypass the IMA and keep the DC-DC converter just by unplugging the BCM and leaving the battery installed.


Will this still keep the 12V charged? It sounds like it should per research in Insight Central..

Also, will the CEL and IMA lights still be on with the bypass? I was still getting lean burn with the IMA/CEL lights on today. Lean burn is a non-negotiable must have. Having the IMA/CEL lights off is a bonus. If lean burn won't work with the bypass then I'll have to see if I can shut the lights off by spoofing something.

Ecky you said you lost lean burn with your bypass? How and why? Did you ever get it back?

Going to try the bypass tomorrow..

Unplugging the BCM works great. 12v will stay charged, though without the battery buffering it, charging will shut off for a few seconds if you rev over 4,000. I never found this to be an issue.

When you pull the battery out entirely you need to connect the high voltage leads that went to the battery directly to the pigtail coming from the DC-DC, so it can get voltage from the MDM to step down to 12v. Hit me up when you decide to do this, it's a pretty simple operation.

You'll have a CEL but no IMA light unless you add an Arduino to fool the ECU. Total cost can be less than $10 to make this, but you need to cut up the wire harness that went to the IMA system which makes it irreversible unless you have a spare. I might have a spare. Most cars won't lose lean burn, mine seems to be one of the rare cases. There are workarounds, but it ends up being a slightly more complicated procedure.

Hope this helps!