Aerocivic - how to drop your Cd from 0.31 to 0.17

[basjoos]

It was 10 years ago that I started aeromodding my Civic CX to create the Aerocivic and I've put over 200,000 miles on it since that time.

[Cd]

Glad to see you posting again Basjoos. You've been missed !

[aerohead]

Originally Posted by basjoos

It was 10 years ago that I started aeromodding my Civic CX to create the Aerocivic and I've put over 200,000 miles on it since that time.

You've probably put 2,000,000,000 'smiles' on all of us!
What a fabulous project! Can't say thanks enough.

[basjoos]

I just made my first interstate road in the aerocivic since last summer and every time I take it out on the interstate its performance continues to astound. Mileage (mpg) in the low 70's while travelling at speeds (mph) in the low 70's. Cruising along in lean burn at 80mph with the faster traffic with plenty of lean burn headroom still available. Nothing else come close to that kind of mileage at those speeds.

[elhigh]

You're the man, man. Since you're asking so little of your engine to hold cruising velocity, I imagine the engine could be reasonably expected to last longer.

[Ecky]

Have you ever considered swapping in an Insight's 3-cylinder engine, and running it without the hybrid systems?

[MetroMPG]

Mike: thanks for the update!

Now I'm curious what you're driving when not using the Aerocivic.

[basjoos]

I use the aerocivic for all of my local driving when I'm not hauling loads for the farm. For that I use a 97 Ford F150 long bed 4wd. I just don't currently do much long distance interstate driving except when I go to visit relatives. The F150 has a grill block and gets 18 to 21 mpg, but that includes off road around the farm and stock trailer hauling.

The main problem with swapping an Insight 3 cylinder motor into the aerocivic is that it won't lean burn over as wide a range of conditions as the Civic VX lean burn engine does. It certainly wouldn't lean burn at 80+mph.

[Ecky]

I was under the impression that BSFC wasn't necessarily any lower in lean burn, but rather, it was a way to have something like a smaller displacement motor (much lower pumping losses) when cruising on the highway, by opening the throttle plate up. I can't imagine the smaller 3 cylinder motor would deliver any worse economy. Consider the reverse - do you suppose the VX's 4 cylinder would perform better in an Insight than the 3-cylinder it came with?

[elhigh]

Originally Posted by basjoos

The main problem with swapping an Insight 3 cylinder motor into the aerocivic is that it won't lean burn over as wide a range of conditions as the Civic VX lean burn engine does. It certainly wouldn't lean burn at 80+mph.

Won't it? I thought LB was conditional on the load on the engine. How does the Aerocivic's aerodynamic load at 80 compare to the aerodynamic load of an Insight at 60?

All things considered I think at this point it's a matter of radically diminishing returns. I imagine there's a significant weight saving to be had however.

Hmm, looking on Wikipedia - which means this info is absolutely ironclad - the ECA1 engine in the first-gen Insight is related to the kei-class three-pots in some Japanese models. That's interesting.