Hybridfest 2007 videos

[TheForce]

Here is my last video.

Tony Schaefer, Top Five Tips For Better Mileage, From Hybrids to Hummers
http://video.google.com/videoplay?docid=-1...81104&hl=en

[brad34695]

<div class='quotetop'>QUOTE(TheForce @ Jul 27 2007, 08:04 PM) [snapback]486454[/snapback]</div>

Wayne Gerdes, The Hows and Why of Hypermiling
http://video.google.com/videoplay?do...40436866161039
Hobbit, The Prius - A Detailed Look into How It Performs the Magic, Part 1
http://video.google.com/videoplay?do...34709053376458
[/b]

Thank you so much for posting that lecture. I learned quite a bit about hypermiling, especially about going over sidewall max tire pressure. Does anyone run 50 lbs psi?? Wayne "sugguests" that is the optimum tire pressure. Again, thanks for posting !!!!!!!!!!!

Brad
Tampa Bay Florida

[orracle]

<div class='quotetop'>QUOTE(brad34695 @ Jul 28 2007, 06:45 PM) [snapback]486832[/snapback]</div>

Thank you so much for posting that lecture. I learned quite a bit about hypermiling, especially about going over sidewall max tire pressure. Does anyone run 50 lbs psi?? Wayne "sugguests" that is the optimum tire pressure. Again, thanks for posting !!!!!!!!!!!

Brad
Tampa Bay Florida
[/b]

I talked to several people who go over 50 psi and some much higher than that. I'm only in the low 40's

[diamondlarry]

I've had 65 psi in the Integrity's since the day I drove it off the lot 4K+ miles ago. I drove accross the street to a gas station, pumped up the tires, got something to eat, and headed home and have had no issues, uneven wear or otherwise since other than a 73.7 mpg average.

[FL_Prius_Driver]

<div class='quotetop'>QUOTE(diamondlarry @ Jul 29 2007, 11:49 AM) [snapback]487080[/snapback]</div>

I've had 65 psi in the Integrity's since the day I drove it off the lot 4K+ miles ago. I drove accross the street to a gas station, pumped up the tires, got something to eat, and headed home and have had no issues, uneven wear or otherwise since other than a 73.7 mpg average.
[/b]

What pressure would you consider to be overinflated?

[diamondlarry]

<div class='quotetop'>QUOTE(FL_Prius_Driver @ Jul 29 2007, 06:02 PM) [snapback]487195[/snapback]</div>

What pressure would you consider to be overinflated?
[/b]

I'm not sure what I would consider overinflated. I have tried 70 psi and haven't noticed a significant FE improvement over 65 psi. I think that 60-65 psi must be around the point at which the FE benefit levels off. Tire condition has been a factor for me in the past. A few years ago, my grandpa wasn't driving his truck much anymore so he gave it to me rather than just junk it. It was a '78 F-250. I rarely drive it since it only gets 9-12 mpg. I only use it for hauling things that won't fit in the car. Anyway, when I got it, the tires had way more than 75% of the tread left but the tires were nearly 15 years old and the sidewalls were cracking. The tires were rated for 65 psi but I didn't feel safe in pushing them past 45.

[FL_Prius_Driver]

There are two aspect of a pressure that high. One is that it puts a larger stess on the tire than ideal. Do not know if this a real issue or not. Given the surge pressures when a tire hits a pothole, it cannot be an acute problem. Do not know if there are chronic problems with uneven wear.

The other issue is road traction. Radial Tires are designed with a certain amount of contact area. Again I do not know how much this is changed going from a recommendation of 35 psi to 65 psi, but it seems to be awful high. If the MPG keeps going up as you inflate the tire, when would you stop inflating? I guess that was my real question. I am not pro or con in this discussion, I just wanted to know why set your limit at 65 psi.

[Neicy]

If you watch the video of Wayne Gerde's talk at Hybridfest '07, he talks about how there is a point where the mpg gain levels out as you inflate the tire increasingly higher, so to a point there is more advantage to higher tire pressures, but the percentage of mpg gain does not stay the same. Watch the video of his talk. It has lots of excellent information.

[diamondlarry]

<div class='quotetop'>QUOTE(Neicy @ Jul 30 2007, 06:45 PM) [snapback]487655[/snapback]</div>

If you watch the video of Wayne Gerde's talk at Hybridfest '07, he talks about how there is a point where the mpg gain levels out as you inflate the tire increasingly higher, so to a point there is more advantage to higher tire pressures, but the percentage of mpg gain does not stay the same. Watch the video of his talk. It has lots of excellent information.
[/b]

That about covers it. Once you get up to a certain point(65 psi seemed to be that point for me), the mpg benefits level off and the ride gets even harsher if psi goes higher.