Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Starting to think 2010 Prius has flow separation issues. Comments?

donee · 11-13-2010, 11:36 PM

Hi All,

Welp, I took the car to the dealarship, and had the alignment check. Since it was dead on perfect as one would expect, I paid the $130 for the check. The local independant shop I favor for alignments could not do the work as their software did not have the 2010 Prius update.

So, this coasting problem is not the toe-in being outboard. The front spec is 0 to .20 degrees inboard, and my car varied but was never out of this spec with manipulation of the front end. Apparently, Toyota has tightend up on this spec from the Gen II. The left rear was near specification nominal (spec -.01 to +.29). The right rear was a little towards the outboard spec limit (-.01 degrees) but still inboard (.04, and .07 in the two measurements).

So, this is getting interesting now.

I saw some side-by-side pictures of the Gen II next to the Gen III. The Gen III is a much wider/lower design, where the Gen II has a much more square aspect cross-section. This may mean the flow delamination may not be over the top, but around the sides. As the air has further to go to get back into the undisturbed flow around the sides.

If I can proove that, then one fix would be vertical plates at the rear of the car, set just inboard of the lights.

Take a look at the Aerocivic, and its a quite square cross-section car too.

11-13-2010, 11:36 PM	#21 (permalink)
donee EcoModding Apprentice Join Date: Jan 2008 Location: Chicagoland Posts: 204 - - '10 Toyota Prius III w/Navi Thanks: 4 Thanked 12 Times in 12 Posts	Hi All, Welp, I took the car to the dealarship, and had the alignment check. Since it was dead on perfect as one would expect, I paid the $130 for the check. The local independant shop I favor for alignments could not do the work as their software did not have the 2010 Prius update. So, this coasting problem is not the toe-in being outboard. The front spec is 0 to .20 degrees inboard, and my car varied but was never out of this spec with manipulation of the front end. Apparently, Toyota has tightend up on this spec from the Gen II. The left rear was near specification nominal (spec -.01 to +.29). The right rear was a little towards the outboard spec limit (-.01 degrees) but still inboard (.04, and .07 in the two measurements). So, this is getting interesting now. I saw some side-by-side pictures of the Gen II next to the Gen III. The Gen III is a much wider/lower design, where the Gen II has a much more square aspect cross-section. This may mean the flow delamination may not be over the top, but around the sides. As the air has further to go to get back into the undisturbed flow around the sides. If I can proove that, then one fix would be vertical plates at the rear of the car, set just inboard of the lights. Take a look at the Aerocivic, and its a quite square cross-section car too.