Project: Zombie Insight

[RobertSmalls]

My fuel economy has thus far been below my expectations. This means I have work to do.

Despite the disappointing fuel economy, I'm absolutely thrilled with the car. It drives much differently from any other car I've driven. The car has turned a few heads, which means I really have to make it look pretty before I make it my daily driver.

This car is fun around town. Its low center of mass and long wheelbase make it quick in corners. The BSFC sweet spot is at 4000RPM, 70% throttle, which means spirited acceleration won't hurt the gas mileage, provided you follow it up with wise driving, like lean burn or EOC.

IMA makes hypermiling easier, faster, and more relaxing. Instead of DWB, you have regenerative braking. Instead of cursing every time someone cuts you off or you catch a light wrong, you just regen, and recover a good percentage of your kinetic energy, storing it for later use. If you find yourself at low RPMs, but you suddenly need to accelerate, no need to downshift. Just use the IMA assist. If you're at a red light with the engine off, you don't need to watch the red light with your foot on the clutch and your hand on the ignition. Shift out of neutral, and the Insight's engine is started before you're ready to let the clutch out.

On the interstate, the car feels stable and is so much quieter than the Subaru at 75mph. 75mph corresponds to 2600RPM, and 55mph is 1900RPM. That's great for fuel economy, but it means you have very little spare power available from the throttle pedal. You have to downshift to fourth or even third to hold your speed up certain hills. Want to pass someone? You'd better plan ahead. I love that.

Lean burn gave me around +8mpg, but you can't make more than, let's say, 15HP in lean burn. I engaged lean burn down hills and while drafting tractor trailers (from at least 1.5 trailer lengths away, don't worry), but on flat ground, I could only lean burn up to 68mph. I will increase the lean burn threshold by improving my aerodynamics to reduce the engine load at any given speed, and with a hot air intake. I intend to lean burn the entire way across the state of Ohio at 74mph at Thanksgiving.

Btw, here are some FE figures:

88.5mpg at the AMEC FE Run IV
68.3mpg @ ~65mph, being careful to hold lean burn
57.8mpg @ 70-74mph, on the way home from AMEC FE Run IV.
~61mpg on the way home from work today. Some traffic.

[MetroMPG]

Robert - congrats on getting the Insight on the road ... and in time for the AMEC competition!

[Old Mechanic]

Robert. in my VX 3rd gear was good for over 100 MPH, although I never came close to that speed.

If you want great mileage on your Insight at high speeds find a nice drafting source, and keep your braking distance between the source and yourself in the right lane, so you can react if you see a large chunk of debris.

My CVT gets about 85 at a steady 40 MPH, 70 at 55, and 65 at 62 MPH. I can get much higher if there is a drafting source, easily one time I got 80 at 62 for 25 miles.

Your manual should be able to easily beat those figures, but the area you live in has much more harsh winter weather than eastern Virginia. Definitely consider a block heater if that is practical, or a garage. Move the outside temp sensor near the radiator so it will not loose idle stop in cold weather.

Great save on the Insight, it is a great car to learn energy conservation with, and you might just get to your goals at high speed, if you take advantage of potential wind breaks to reduce your energy demand.


You definitely want to block off almost all of the lower grille opening if you haven't already.
regards
Mech

[RobertSmalls]

I just noticed, the last picture I've posted in this thread showed the car still missing its headlights, front bumper, and a fender. Here are some updated photos.



The photo below was taken by Wonderboy at the AMEC FE Run IV. It shows my handiwork on the front bumper / grille block. The center of my bumper cover was mangled, so I cut away the middle 3' of it and screwed a piece of coroplast in its place. I screwed the license plate directly to the coroplast.

Peeking out from behind the coroplast is a Dartmouth College parking permit for '03-'04. Hopefully the previous owner took good care of the car.

[RobertSmalls]

It was 35°F this morning when I left for work today. To permit lean burn in temperatures like these, and to widen the lean-burn window during warmer weather, I installed a warm air intake.




I bought a 36" length of 2" pre-heater hose for $10 at NAPA. It's basically a flexible, foil-lined paper tube. I ran it from the factory airbox, under the battery tray, over to the cat. It actually ends about 1.5" away from the cat.

This WAI is good for +20-30°F above ambient, once the cat gets hot. IAT's start to rise after about two miles, and it takes about five miles (of my ten mile commute) for IAT to reach its maximum.

It works. Despite the cold, I was able to lean burn quite a bit on the way to work, and I got 66.0mpg, which is 5mpg better than my average commute thus far. On the way home, I had IAT=75°F and lots of lean burn. I managed 59.9mpg despite bad traffic.

As an added bonus, the new intake is about 900g (2lbs) lighter than the old one. In a car that started at 1837lbs, that matters.

I need to reduce airflow through my engine bay even further. This engine barely produces enough heat to run the defroster anyway, and now I want to make sure my cat stays toasty, for the sake of emissions and intake temperature.

To do: An undertray, complete from the bumper to the firewall. The front half will be easy, but the back half has to deal with the cat and the suspension.