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-   -   Where did Honda compromise with the Insight? (

bikeracer 01-31-2010 08:57 PM

Where did Honda compromise with the Insight?
So Honda seems to have made remarkably few concessions to practicality when designing the Insight (Gen 1 in particular, more concessions (800+lbs) in the 2010). I'd love to get everyone's thoughts on where they might have traded some additional drag for some modicum of practicality. The grill opening seems to be one place. They might have gone with more pronounced tire spats as well. They added a rear wiper to the hatch.

Just throwing out a few. It would be interesting to mention how they've designed the rest of the body around these compromises—no front wheel skirts means that the trailing edge of the wheel well is rounded and recessed, for example. Just taping on skirts wouldn't do as well as addressing the compromise they made to lessen the impact of not having them in the first place.

I hope to prototype and test a lot of ideas come warmer weather and the completion of my thesis.

Also, is anyone familiar with a foam called Zotefoam? I ran into it being used to make fairings...The Recumbent Bicycle and Human Powered Vehicle Information Center

luvit 01-31-2010 10:37 PM

the rear wheel skirts are missing. they may have designed it so there is no measurable loss just for the skirts to be missing, but the skirts made a statement.


bikeracer 01-31-2010 10:43 PM

The 2010 seems to have made quite a few more concessions to boot. Interestingly, one driver I know says his favorite feature of the 2010 is the fact that he can have the windows down at speed and it's still quiet inside. It's probably the same design considerations that make the rear wheel skirt absence less of an issue.

jamesqf 01-31-2010 11:03 PM

The original - I've owned one for the last six years - is wider and taller than I'd like it to be. The doors have always annoyed me, since they're about 6" thick (but all empty space inside), and don't even have pockets to make use of the space.

There's also quite a bit of extra space in the engine compartment, everything considered, and in the battery/inverter area. Understandable for a first generation, but I sure wish they'd done a second, instead of slapping the name on a completely different car.

RobertSmalls 01-31-2010 11:11 PM

If we were talking about aerodynamic compromises made by Honda in the design of the first-gen Honda Insight, I can think of several: grille, underbody panels, the size of the car's trailing end, height and width of the car, and things that stick out into the airstream.

The biggest room for improvement is at the rear of the car. Foremost, the Insight needs a boat tail. Yes, it would be large and at times cumbersome, but if you need the best possible aerodynamics, you need a boat tail. I presume Honda omitted it for very good reasons. It would be hard to park a boat-tailed Insight in Japan and Europe, and possibly hard to sell such a car in America. There are also crash safety questions, namely: can you design a 5mph bumper that's 50cm wide? If you are rear ended at high speed, would such a boat tail act like a trench spike through the firewall of the guy behind you?

Notice how the bottom half of the rear is much less tapered than the top half. The rear track width dictates the width of the rear. I'm not suggesting you should move your suspension inward, but hey, it would improve CdA.

IMO, air should not travel through the engine bay, except as required by the radiator. Honda's gasketed hood and engine bay underpaneling are good, but both can be improved on slightly. A more complete engine bay cover increases the cost/hassle of servicing the vehicle. If you complete that and a grille block, you may want to reduce the size of the engine bay to wheel well passage too.

There are a few simple appendages that hang out in the airstream. In order from largest CdA to smallest: wing mirrors, rear wiper, door handles, antenna, washer fluid nozzles (x3), raised hood emblem. Some of these things are very necessary on a road-going car, while others were added to conform to regulations and/or consumer expectations. Of these, I've only removed the rear wiper, and I plan to remove the mirrors, antenna, and one washer nozzle.

Frontal area reduction would help. I could still seat two side-by-side with a few inches less overall width, though it would be uncomfortable when large people are in the car. Likewise, the roof could be lowered by reclining the passengers more or excluding tall people.

The Insight has 5.9" of ground clearance. A lower design would reduce CdA, though lowering the car yourself is not guaranteed to do so. I would favor more aggressive fairings in front of and behind front and rear tires, even though they'd likely come in to contact with pavement at some point.

The Insight leaves the factory with an excelled Cd=0.25. I wonder if 0.20 or even 0.17 is within the reach of an EcoModder.

Piwoslaw 02-01-2010 02:47 AM

As jamesqf noted, this isn't comparing changes from one generation of Insight to the next, it's comparing two totally different cars with the same name.

Of course, we should pay attention to what Honda could have done better with the Insight II (that's what we're here for, right?). In my opinion, if it's called the Insight, then it should have more in common with gen1 then just "being a hybrid".

Daox 02-01-2010 07:22 AM

A big part of the Insight II disappointment IMO was because it could not tred on the Civic Hybrid's toes. The Insight II was to cost less, so it could never be as great as the Civic, otherwise it would kill their sales there. One thing I know is, they purposely geared it higher than the Civic which hurts the highway mileage.

jamesqf 02-01-2010 12:21 PM


Originally Posted by RobertSmalls (Post 158137)
The Insight has 5.9" of ground clearance. A lower design would reduce CdA, though lowering the car yourself is not guaranteed to do so.

Do not think about this if you live in an area subject to sudden heavy snowfalls, though. The only time I came close to getting stuck (and that within a mile or two of home) was when a sudden (and localized: there were only a few flakes when I left the lab about 15 miles away) storm dumped about 8".

3-Wheeler 02-01-2010 09:28 PM

1 Attachment(s)

Originally Posted by RobertSmalls (Post 158137)
....Notice how the bottom half of the rear is much less tapered than the top half. The rear track width dictates the width of the rear. I'm not suggesting you should move your suspension inward, but hey, it would improve CdA....


Take a look at the photo below. Notice how you can make out the rear wheels inside the front wheels. This displaces more air than if they were in line, front to back.

So was it worth it for Honda to move the rear wheels inside of the front to taper the rear panels of the car??

It's always a compromise...


luvit 02-01-2010 10:22 PM

they are in-line.. not only airflow, but snow and water traction is better when they are in-line.

by the way, did you know that parallel lines eventually meet?

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