Aero-AntiCorrosion Mod to Trim Rings..

[donee]

Hi Holy...,

Hard to say. Daily driving here has been so variable. I was at 57.5 mpg at the end of the day on Thursday last week, but then had to drive in 1 inch slush on the road on Friday in a short trip at 35 F, and more short trips over the weekend. By Friday this week I was down to 53.8 mpg.

Weather is just too variable here to say wether they are helping or not. It was 60 F deg last thursday, and today we are waking up to 20 F, and as I mentioned above the day after 60F was a slush storm at 35 F. Low traffic levels somedays, and heavier traffic with snow the other days just makes it unpredictable.

They are not getting all banged up though, like some of my ME work colleagues preditcted. They look pretty much the same as the day I put them on.

A true test will be some kinda down hill coasting test, and see what the final speed is at the bottom of the hill with them on or off. But or course its not good to coast in the Prius tranny above 40 mph, and 60 is the absolute max with engine off. Which is really not fast enough to get a see the difference for such a small aero mod. 75 mph should show the difference more readily. We do not have any hill long enough here to coast up to 75 mph in this area.

Cruising at 75 would not work, unless you had two Prius driving the same road at the same time both in cruise control for the same period, one with the hubcaps, and one without, and with no other traffic on the road. That is a hard situation to setup here in Chicagoland.

I will be setting up a MyScanPC (already have the EEE PC) to get some data acquistion. Possibly then I will be able to quantify a change.

I did get a compliment on them the other day. The guy said it made the car look very futuristic when driving down the road. I occasionally see people in the passenger seat do a double take looking at the wheels.

[donee]

Hi All,

I have moved my front driver license to a mid lower grill position as well now. I used J-hooks from Ace Hardware and stainless steel nuts and washers in front and behind the the plate to adjust the fit and clamp the plate . I originally was going to use 4 J hooks, but two on the top two holes of the plate worked just fine. The J hooks are slightly pulling upward , and the plate is keyed into the recess for the grill. I used a piece of plastic tubing slit lengthwise to make a chafe gard on the plastic bumper protector. Its a very secure fit.

The idea behind this is a that the bumper protector is now a smooth blunt body aero surface, rather than having the plate protruding on its braket.

This makes a permanent 1/3 lower grill grill block, which may not be appropriate from hotter climates and mountain climb application, however.

[danatt]

Originally Posted by donee

Hi Clubford,

Take your self a long trip, and bring your Prius home. Then reach into the hole in the wheel and feel the heat with a knuckle. Do not try this on a regular car!

I have done this and gone all the way to touching the disks. They were about 100 F or so. The Prius does not use its friction brakes until 7 mph in normal braking. It uses them only when the battery gets full (long downhills) and panic stops. We do not have long downhills here in Chicagoland. I will be sure to take them off at a rest stop in Nebraska before I proceed into the front range. But around here the disks are getting pitted from non-use.

Most of the braking energy of a Prius goes into the MG2 motor, and onto the batteries. In a regular car where all the slowing energy goes into those disks they run at 300 F or so in metropolitan area driving. My knuckle tells me not to get any closer to 1/2 an inch on those.

Great post donee! I've always known that one of the great things about the Prius was how it recaptured much of the energy in braking, rather than just burning up brake pads. But you've shown how we can demonstrate that in a practicle way. Thanks!

BTW - is there any data on life of brake pads on the Prius vs. conventional cars?

[donee]

Hi All,

Several months ago I found a problem with using the stock Prius (I think they were?) valve caps with the metal extenders.

Do not use the stock Prius valve caps on those metal extenders as shown in that picture. Only use the metal caps sold seperatly by the same valve equipment manufacturer. The Prius plastic valve caps have a small ring down in the cap which can cause a slow leak due to the design of the metal valve extenders. The ring alignes the cap into the normal ruber valve stem, so the O-ring in the cap seats properly. The metal extenders have a dust cover which the ring will push down on, and cause an open air path through the extender. The cap limits the leakage, but if it were to be hit by something and cracked, you could see your tire deflate rapidly while at speed.