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Old 09-03-2018, 10:27 PM   #82 (permalink)
Ecky
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Join Date: Dec 2011
Location: New Zealand
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ND Miata - '15 Mazda MX-5 Special Package
90 day: 39.72 mpg (US)

Oxygen Blue - '00 Honda Insight
90 day: 58.53 mpg (US)
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Quote:
Originally Posted by mpg_numbers_guy View Post
3. A lot of these maintenance issues seemed to come from the battery/hybrid system. Looking at it statistically, say I could manage 70 MPG without the hybrid battery, and 100 MPG with the battery. I estimate roughly 10,000 miles/yr - roughly 143 gallons without battery and 100 gallons with battery. At approximately $3/gallon that's $300/yr with battery and $429/yr without battery. A new Bumblebee battery costs $1995 (not including installation costs). Even if I could make a battery last 10 years, my savings with the battery is only $1290, compared for over $2000 for new battery + installation. In order to make having a battery actually save any money, I would need to average 116.7 MPG with the battery if the battery lasted 10 years OR drive 15,555.6 miles/yr, again if the battery lasted 10 years. And that's with me installing it myself, which I don't know how to do, and most hybrid batteries don't last 10 years unless you spend $100s in maintaining the battery, which in the long run can't really be that much more efficient.

4. Another question, how much really does the IMA battery help fuel efficiency? Am I wrong or does the battery only come into play during acceleration and hill climbing? Regen benefits are negligible by EOC. I read in Ecky's thread that without the battery shift points at 3000-4000 RPMs were necessary during acceleration as opposed to 2000 RPMs, obviously burning...4x more gas in acceleration? But other than that, how much really does the IMA battery help fuel efficiency?

5. Without the IMA, does electrical load still affect MPG signficantly compared to other cars? I.e. radio usage, headlights, etc. AC will be deleted.

3) The hybrid batteries won't save you money overall. But, they make the car a lot more fun and pleasant to drive, and to me that counts for something. It's cool as hell to have auto-stop and for it to silent start, for the car to automatically restart the engine if you stall it, to have 3x the acceleration at low speed without any extra fuel usage, to keep engine wear (and cabin noise!) down since you never need to rev it high.

That said, taking the battery out is really very easy. I'd rather do that than replace a serpentine belt on the engine, as a point of comparison.

4) You can check my thread about economy. It does help somewhat, but not at all on a flat road at steady speeds. Mostly it helps mitigate conditions that would sap mileage like stop and go traffic, idling, climbing hills and needing to pass or merge into traffic quickly.

5) I've found electrical load doesn't affect this car as much as other cars, probably because it's more far efficient than an alternator, and the car's base electrical load isn't as large as with many vehicles. It's more than a Geo Metro, but far less than virtually anything else manufactured after 2000.

Leaving the A/C compressor in the belt loop also doesn't seem to hurt mileage, and the system weighs only around 50lbs - most who have deleted it have noticed zero measurable improvement in mileage. You'll probably spend more on the replacement belt than you'll save by taking the system out. It's nice to have sometimes, to be able to defrost or defog windows, or when you have a passenger or pet who is heat sensitive. However, turning the A/C on affects acceleration (and ease of driving) a LOT more in the Insight than in any other car I've ever driven, presumably since it's not a smaller compressor than in a Civic, despite the engine being half the size. The A/C can really crank.
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