Aeromodded Civic VX 72mpg (image heavy)

[The donkey CRX]

Before any modifications on the VX, I could get into the low 60's to low 70's depending on the weather (hot good, cold bad or rain or wind). One reason I can good get high MPG is I drive the same 108 mile route each day. I can practice different techniques to improve MPG in each section

[basjoos]

That's about the same mpg's that I was getting out of my stock Civic CX by hypermiling it before I started aeromodding. The main reason I started down the aeromodding path was that I could only maintain that high mileage by keeping the speed mostly below 50 mph, which was hard to do since I was driving mostly on the interstates. Aeromodding allowed me to maintain that same high mileage at normal interstate speeds which I couldn't do with the stock vehicle shape.

[basjoos]

Originally Posted by ultimx

I was also considering making the front bumper more rounded and longer in the front to help" break through" the air but idk how that will work out yet.

The main advantage of rounding the flat portion of the front bumper is to lower the stagnation point to a height close to the level of the bottom of your car. It also gets rid an efficient collector of dead bugs. One advantage of the aeromodded shape is that you have very few dead bugs to clean off the front of the car. Also the rounded front end can provide a space to an install an adjustable grill block and adds additional crush space for added safety in the event of a front end collision.

[California98Civic]

Originally Posted by basjoos

The main advantage of rounding the flat portion of the front bumper is to lower the stagnation point to a height close to the level of the bottom of your car.

I could understand that it would do that, but won't doing so produce a lot of downforce? How would it interact with the rest of the car? I would imagine with more air going over the car from the nose, that the back end matters even more. True or a mistake? What do you think?

[The donkey CRX]

The benefit of aero mods that I like is that no matter how much effort you are putting into hypermiling, you always get the aero "bonus". Right now I am able to Pulse to a speed 5 MPH lower (55 instead of 60) going down a hill and still be at a higher MPH at the end of my EOC.( I don't EOC much on the freeway part of my commute).

That tells me that aero is always my friend no matter my effort or the weather!

Maybe once the pure fun of being able to get 80 MPG at 55 on the freeway and 45 or 50 on the country roads wears off, I will step it up 5 MPH, maybe.

I totally understand that if I wasn't retired and don't need to be at the shop at a certain time, I would probably speed it up to the speed limit all the time.

When I was making this commute in my pickup at the speed limit, it would take about one hour and 5 minutes one way (54 miles). Now it takes me about one hour 25 minutes. I hope all of you can take an extra 40 minutes a day to have this much fun when you retire.

[Baltothewolf]

Originally Posted by The donkey CRX

The benefit of aero mods that I like is that no matter how much effort you are putting into hypermiling, you always get the aero "bonus". Right now I am able to Pulse to a speed 5 MPH lower (55 instead of 60) going down a hill and still be at a higher MPH at the end of my EOC.( I don't EOC much on the freeway part of my commute).

That tells me that aero is always my friend no matter my effort or the weather!

Maybe once the pure fun of being able to get 80 MPG at 55 on the freeway and 45 or 50 on the country roads wears off, I will step it up 5 MPH, maybe.

I totally understand that if I wasn't retired and don't need to be at the shop at a certain time, I would probably speed it up to the speed limit all the time.

When I was making this commute in my pickup at the speed limit, it would take about one hour and 5 minutes one way (54 miles). Now it takes me about one hour 25 minutes. I hope all of you can take an extra 40 minutes a day to have this much fun when you retire.

I travel 38 miles each way to work and back everyday (out right now due to car accident) and I leave a little early just so I can drive slower to get more MPG and I'm far, far from retirement :P.

[basjoos]

Originally Posted by California98Civic

I could understand that it would do that, but won't doing so produce a lot of downforce? How would it interact with the rest of the car? I would imagine with more air going over the car from the nose, that the back end matters even more. True or a mistake? What do you think?

Lowering the stagnation point forces more of the air to go over the top and around the sides of the car, thus avoiding the roughness and turbulence of a passage under the car. Even with smooth underpanelling, there is the turbulence of its interactions with the wheels so the more of this air you can divert elsewhere the better. Lowering the stagnation point reduces drag, but it also tends to reduce downforce, since any air going over the top of the car acts like air going over the top of an airfoil, creating lift. This added lift might cause stability problems at 100+ mph speeds, but isn't a problem at usual highway speeds and you can cancel out some of this lift with no increase in drag by building a rear diffuser panel on the rear underside of the car.

[j12piprius]

The donkey CRX, did you remove the molding to help mpg? I suppose it's only purpose is dent protection for the doors, which might not be a good reason for me to keep it.

[j12piprius]

Originally Posted by johnlvs2run

How did you decide on the 6 inch clearance? Most of the underbelly on my car is at 8 inches from the ground, with some at 7. Do you think it would help or hurt to have the airdam lower than the belly?

Basjoos, what is your opinion on this? I'm planning to have the same type of nose as Aerohead & The donkey CRX. I'm thinking to cut the plastic at 7 or 8 inches from the ground, but wondering if 6 inches would be better.

[California98Civic]

My airdam is probably only 4 inches off the ground, IIRC.