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Old 08-22-2018, 11:24 PM   #26 (permalink)
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ND Miata - '15 Mazda MX-5 Special Package
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Originally Posted by mpg_numbers_guy View Post
Is it really just that simple?

Does the HCH/Insight have an alternator that needs to be disconnected/deleted? This then solves the issue of needing to be between 1500 & 3800 RPMs for charging the battery?
Really that simple. Neither car has alternator or power steering pump. The only belt accessory is air conditioning.

In the case of 12v charging, you're replacing a very-good-for-a-15 year-old design with a better, new design with wider input voltage tolerances. It will keep the 12v system charged and happy as well or better than an alternator with higher efficiency.

Power steering is also electric on both cars, and both very efficient and reliable. Owners have seen zero improvement in economy from disabling this system. However, while the Insight's EPS is light and playful, I found the HCH1's to be quite heavy. Higher tire pressure would probably help, but if there's one gripe I have with the HCH1, it's the weight of the steering. It's honestly a great car overall.

Originally Posted by mpg_numbers_guy View Post
I say "simple" although I've never really done any wiring stuff on cars before; however I enjoy learning new stuff and a few youtube tutorials should get me going along with your diagram once I get an HCH...or an Insight...I'm still debating...

Wowsers. I'd say 50-55 MPG would be a "realistic but non-trivial" goal for my car, although by extreme hypermiling I can get 60-70. That'd be a 33% in and of itself over my current car with the HCH and 75% better with the Insight. Would that be with/without battery and ecomods?

Me want...but what about impracticality!

If I can find a good Insight next spring and I don't see a super tempting HCH...I just might go with the Insight.
I can't speak for the HCH, I've only ever driven one with a good battery, but 50-60mpg was laughably easy with zero modification. I have no idea if it will keep lean burn without the hybrid system, but I'm inclined to think it will.

Some other items worth mentioning:

The Insight has a ready-made solution for turning off the CEL with the hybrid system removed, which costs less than $15 to assemble. This could probably be done for the HCH as well, but there isn't the same community support so you'd be mostly on your own in figuring it out - if that's important to you at all.

Also, the G1 Insight has a flaw in the transmission which causes most of them to develop a gear grind when downshifting into 2nd from a higher gear. This developed in mine around 200,000 miles. A shifting technique called double clutching lets you shift into this gear anyway without grinding and isn't hard to learn, but again, worth noting. It's possible to permanently fix this (for free) by opening up the transmission. There are good how-to guides both on here and on InsightCentral, but I don't have easy access to drop my transmission so I just double clutch around it. Aside from that and the batteries, both cars are silly reliable. One member on IC has something like 400,000 miles on his Insight engine... with a turbocharger.

Last edited by Ecky; 08-22-2018 at 11:38 PM..
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