Long trip ahead, little prep time - best aero mod?

[COcyclist]

Originally Posted by Cd

I'll try to search for the image of the TDI Jetta I spoke of with the catfish style spoiler.
If I find it I will edit this post and attach it for you.

Edit : I looked for the image i was spoke about earlier, but could not find it.
Here is an example of what I'm talking about though : The sides cover the wheels, yet the air dam is trimmed in the center to reduce frontal area.

I believe the Jetta you spoke of belongs to Tasdrouille?? He is French Canadian IIRC and it means "rust bucket". I haven't searched for the photo yet.

Nacht, you are doing great with your Jetta. I would love to swap a 6 speed into my Golf to get a higher top gear. I have done a full belly pan- see photos in my album. It was about 2 days on my back and part of another extending the rear fenderliners and sealing up around the rear wheelwells (recommended). I have also done the passenger mirror delete and it was very involved. You have to remove the whole inside panel to get at the mirror mount and you need to have a big (15mm??) Torx bit ready to remove the mirror housing. Luckily, it folds almost flat to the window and I just used velcro to attach a convex mirror on the inside. I ran it that way for years before I committed to removing it altogether. I fold the driver's too on the open highway.

[COcyclist]

http://ecomodder.com/forum/showthrea...15-a-4805.html

Post #9 shows an older Jetta but I seem to recall a Mk IV green Jetta too.

[RunningStrong]

Originally Posted by Cd

I don't think the dam needs to extend to the full width of the tyres, otherwise it tends to throw out a wake that effectively increases the frontal area.

[ecofreak]

Originally Posted by RunningStrong

I don't think the dam needs to extend to the full width of the tyres, otherwise it tends to throw out a wake that effectively increases the frontal area.

Anything to get air away from the tires is ideal. The increase in frontal area wouldn't factor in if it's also funneling air away from the sides of the car.

It's been said before, but the best aeromods would be the pan and a grille cover. Taping over some of the body creases and gaps might also help.

You'd be better off practicing some technique, even though that does eventually involve going to the pump.

[NachtRitter]

Originally Posted by COcyclist

http://ecomodder.com/forum/showthrea...15-a-4805.html

Post #9 shows an older Jetta but I seem to recall a Mk IV green Jetta too.

Thank you COcyclist! I recall studying that thread for ideas a while back too. Great pics! The 79.9mpg is pretty incredible, in fact... if those are US gallons (not imperial!) then doing that with my Jetta would get me 1,200 miles... Wow! That'd be nearly 2/3 of the way there! While I have the patience to drive slower, I don't quite have the patience to drive THAT slow (~47mph ) for 4,000 miles (round trip).

[NachtRitter]

Originally Posted by ecofreak

Anything to get air away from the tires is ideal. The increase in frontal area wouldn't factor in if it's also funneling air away from the sides of the car.

Good discussion about this here: http://ecomodder.com/forum/showthrea...tion-8739.html

Originally Posted by ecofreak

It's been said before, but the best aeromods would be the pan and a grille cover. Taping over some of the body creases and gaps might also help.

You'd be better off practicing some technique, even though that does eventually involve going to the pump.

Are you responding to my original post or just responding generically? I'm not sure how much more would be safe for me to block off on the grill... especially with the climbs I'm showing on the elevation profile. Maybe on the 2nd half of the drive I can try a 100% grill block and be OK with it.

Also not sure who you mean when you say "You'd be better off practicing some technique". Do you mean me (the OP)? I know I can always improve, but I think getting 50%+ over EPA combined when I drive isn't too shabby. Doesn't show on the tank because my wife drives the Jetta too, but even the combination gets us within the top 10 % over EPA for Diesel cars here on ecomodder.

[NachtRitter]

Picked up a few supplies today from storage... a big sheet of coroplast (had saved it from the last election) and a plastic water heater drain pan... I'd used one of those drain pans as a rear wheel skirt on my Honda VX with decent looking results... might be *just* big enough to fit the wheel arch of the Jetta too. Will pick up some more supplies tomorrow.

Played around with Google Earth some more. Plotted two significantly different routes... one across the center of the US and one going across a bit more southerly. The elevation profiles:
Central (same as posted before):

Southerly:


Initial glance makes the southerly route look better (max altitude is 7340ft on this route while the other route has a max altitude of 8520ft). But then there are other details that seem to favor the central route (26,675ft of climbing on the central route vs 28,366ft of climbing on the southerly route; 1931mi for central vs 2159mi for southerly... worth at least 3 hours assuming the same avg speed on each route). Argh! Too much information!!

[Cd]

Just FYI, here are two examples of " trip strips " one on a new Fiesta the other on a new Focus .
One is a vertical break just before curve at the rear of the car , and the other is a ramp style which snags some of the air that has already been detached.



You can easily make your own by using some flexible wire and some electrical tape ( high quality electrical tape won't leave the sticky residue that cheaper tape will. In black it also shows up less )

Here is the clean break ( trip ) line on the Volt as seen from the rear : ( The vertical line just below the taillights )

From what I understand, a vertical 'cut' line just before any aggressive curving at the rear of the car acts to form a clean separation point . Trip strips perform the same function that a spoiler does , but for the sides of the car . That's my understanding at least.

[Cd]

Your car is very similar in shape to a Fusion and may benefit from some of the same mods performed here :

[Weather Spotter]

It looks to me like the central roué is better, also take ambient temps into account. The farther south the hotter it gets, more tempting to us ac and more grill opening needed.

From my experence without a side mirror, do it a week or two before the trip, you will be use to driveing without it by that point. On my car the side mirror removal was good for 1.6 mpg. Smoothe wheel covers were good for 1+ mpg. So I would put thoses up on the list of mods to do before the trip.