Aerocivic - how to drop your Cd from 0.31 to 0.17

[moonmonkey]

does the air not detach from the bottom of your boat tail? that angle is steep how many degrees is it on the bottom i know it works great but just wondering if it was a compromise so as not to knock the tail off pulling into driveways.

[basjoos]

I went with a sharper than optimal bottom angle to keep the tail from dragging when entering steep driveways, so there is likely to be some airflow separation going on. But it isn't much, since portions on the rear of a vehicle that are subject to recirculating eddies tend to get coated with grime or salt, and the underside of my boattail doesn't get any dirtier than the top or sides of my car.

[orange4boy]

How do you like your Nokians? Which ones did you get?

I just got the WRG2s for the Prius and they are excellent.

[basjoos]

Nokian Hakapelitta R 175/70/13. They have more RR than my Bridgestone Potenza RE92, but less than the Sumitomo HTR4 that I was running earlier. Much better on snow and ice than the Bridgestones and they handle fine enough on dry pavement that I wouldn't mind running them year around if I had to. Their only drawback is they take a bigger FE hit on wet roads than the Bridgestones.

[orange4boy]

The Hakkas are excellent tires.

I noticed the wet FE hit too. I guess it's a trade off. Better wet traction but greater RR.

The WRG2 is real all season tire with a M+S rating, but that's probably more like a Finnish all season. In some tests I saw it had better snow traction than some dedicated snow tires. The summer temps south of here will probably wear them down too fast but that's a supposition on my part. They have a 400 wear rating. Very stable and grippy and the 185/65/14XL I got have a 51psi max pressure.

I'm probably going to get a set of LRR Nokian H for the summer. The RR is a little higher than say, the Michelin energy saver, but on every other characteristic they are better. I looked at the i3 but the H has better RR according to the tech guys there. On the other hand the i3 has a UTQG: 620 A A. The H: 320 A A

I looked at the RE92 but the performance wasn't good enough in the wet and snow.

Part of my reason for choosing the Nokian is their environmental leadership and social responsibility. Other than offering some LRR tires, Michelin is dragging it's feet a bit on other environmental issues.

[Ironwood]

I am on my 2nd set of Nokian WR all-season snow-rated (snow flake symbol) tires on my Subaru Forester. I use them year round. The 1st set lasted a bit over 40K miles. I live in central North Carolina so they seldom see a lot of snow but they do see a good amount of summer heat. When they do encounter snow, they perform well. The rest of the time, they do fine on wet and dry roads. I am happy with them.

[WV6Z]

Wow Ironwood! I thought I was the ultimate lurker, but you win! 2 years from joining to making your first post! :O)

[dav8]

Basjoos, have you considered a message for the rubberneckers, painted on the side of your car? Like: 95 MPG, $?/MONTH GAS BILL, MPG CONSULTING $50/HR, ECOMODDER.COM, or ...?

[basjoos]

I have enough problems with rubberneckers without giving them even more information to try to read and comprehend while holding formation alongside me at 65mph. That's why I limited the message on the side of my car to just the aerocivic.com website.

[Angmaar]

The MPG gains are insane from all those aero mods!