Potential fuel economy gains between 44 and 51 PSI? New tires choices. - Page 2 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Go Back   Fuelly Forums > Fuel Talk > General Fuel Topics
Search Today's Posts Mark Forums Read Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 09-17-2011, 08:29 PM   #11
Senior Member
 
FrugalFloyd's Avatar
 
Join Date: Dec 2009
Posts: 383
Country: United States
Location: Bay Area, CA
Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.

Good choice. There've been discussions convincing me there's no difference in tires bearing sidewall maximums of 44 and 51 psi. Three mfrs (Michelin is one) use 44 psi as their sidewall max. You can run 51 psi in them w/o problems.
__________________

FrugalFloyd is offline   Reply With Quote
Old 09-18-2011, 04:35 AM   #12
Registered Member
 
theholycow's Avatar
 
Join Date: Apr 2008
Posts: 6,624
Country: United States
Send a message via ICQ to theholycow Send a message via AIM to theholycow Send a message via MSN to theholycow Send a message via Yahoo to theholycow
Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.

Barry's Tire Tech is an excellent, educational website on tires.

http://www.barrystiretech.com/loadtables.html
Quote:
I want to draw your attention to note #3 and the table that follows:

This note means that in spite of the load curve ending at 35 (or 41 for XL) psi, it is permissible to stamp the sidewall of the tire as having a maximum inflation of 35 psi, or 44 psi or 51 psi. (41 or 50 psi for XL).

If you were to dig to find the US regulation that covers what is supposed to be stamped on the sidewall of the tire (In this yearbook, it is FMVSS109, but this was superseded by FMVSS139 in 2007, but this part reads the same for both), the regulation is unclear which of those values it is supposed to be.

Most everyone in the tire industry reads the regulation that either 44 psi or 51 psi is the proper value for SL tires. However, a few tire manufacturers - notably the Michelin group (Michelin, Uniroyal, and Goodrich) have interpreted this differently and read the regulation to mean that for S and T speed rated tires, 35 psi should be stamped on the sidewall, while H and higher are supposed to read 44 or 51 psi.

That means for otherwise comparable tires, you will find different maximum pressures stamped on the sidewall. This means you SHOULD NOT use the pressure stamped on the sidewall as any sort of reference point, except, of course, what it says - a maximum.
and there are a couple exceptions to that!!

Please note that ETRTO and JATMA have similar notes in their yearbook, except that ETRTO's rated inflation pressure for SL tires is 2.5 bar (36 psi)
__________________

__________________
This sig may return, some day.
theholycow is offline   Reply With Quote
Old 09-19-2011, 07:50 AM   #13
Registered Member
 
palemelanesian's Avatar
 
Join Date: Apr 2013
Posts: 364
Country: United States
Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.

For the record, I've done four sets of tires on both my cars at "above placard" pressures. Two on the Odyssey at max sidewall (one 44 psi and one 51 psi). Both wore evenly across the tread. Two on the Civic at "well above" max sidewall. The tread wear was/is dead even across the tread.

I'm convinced that modern steel-belted radials don't do the often-quoted center wear at high pressure. I think it's because the steel doesn't stretch much. Low pressure and they do cave in a bit and wear the shoulders, but they stay flat at any pressure above "fully inflated". In my experience, fully inflated is above placard and somewhere close to sidewall max. (32 = underinflated, 35 = underinflated, 44+ = fully inflated)
palemelanesian is offline   Reply With Quote
Old 09-19-2011, 08:43 AM   #14
Registered Member
 
IndyFetch's Avatar
 
Join Date: Nov 2008
Posts: 627
Country: United States
Location: Indianapolis
Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.

I had a set of Michelin Destiny tires on my VX. After 40,000 miles, they were less than 1/3 of the way worn. They handled quite well, were not prone to squealing, and offered decent wet and dry grip. The open tread blocks on the shoulders gave great grip in snow at the expense of a little bit of tire hum. I really liked mine, and I hope you have the same luck.
IndyFetch is offline   Reply With Quote
Old 09-19-2011, 08:51 AM   #15
Registered Member
 
palemelanesian's Avatar
 
Join Date: Apr 2013
Posts: 364
Country: United States
Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.

I'm running Destiny's on mine right now. They're noisy, but otherwise I like them.
palemelanesian is offline   Reply With Quote
Old 09-19-2011, 09:22 AM   #16
Registered Member
 
theholycow's Avatar
 
Join Date: Apr 2008
Posts: 6,624
Country: United States
Send a message via ICQ to theholycow Send a message via AIM to theholycow Send a message via MSN to theholycow Send a message via Yahoo to theholycow
Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.

Quote:
Originally Posted by PaleMelanesian View Post
I'm convinced that modern steel-belted radials don't do the often-quoted center wear at high pressure. I think it's because the steel doesn't stretch much. Low pressure and they do cave in a bit and wear the shoulders, but they stay flat at any pressure above "fully inflated".
Well said. I have had center wear, but never severe enough to be worth much discussion; I don't think most people would notice it and I don't think it's what people think of when we talk about it. I agree with your theory about why.

Quote:
In my experience, fully inflated is above placard and somewhere close to sidewall max. (32 = underinflated, 35 = underinflated, 44+ = fully inflated)
Also well said!
__________________

__________________
This sig may return, some day.
theholycow is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 08:03 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.