www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2014 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You



Go Back   TDIClub Forums > VW TDI Discussion Areas > TDI Fuel Economy

TDI Fuel Economy Discussions about increasing the fuel economy of your TDI engine. Non TDI related postings will be moved or removed.

Reply
 
Thread Tools
Old October 22nd, 2007, 11:54   #1
xDieselxTunerx
Veteran Member
 
xDieselxTunerx's Avatar
 
Join Date: Jan 2006
Location: Cypress, TX
TDI(s): None Yet
Fuel Economy: 45+MPG
Default Best tire pressure for best gas mileage?

Whats the best psi to run my tires for the best fuel milesage? I have 205/55R16's right now im running them at 38psi. Is that perfect or too low?
xDieselxTunerx is offline   Reply With Quote
Old October 22nd, 2007, 12:51   #2
kwong7
Veteran Member
 
Join Date: Mar 2004
Location: Southern Caifornia
Fuel Economy: 48/42/45 MPG
Default

I had my 225/45/17 Michelin Pilot Sports up at 42/40 PSI. Over 50K miles, I noticed the middle of the tires were wearing out faster than the shoulders. Over the last 15K miles, I've decreased the pressure to 34/30 PSI and noticed no decrease at all to fuel economy (still getting 45MPG), better braking, traction, less tire squeal, and no more oversteer when taking turns like crazy.

When I had my stock 195/65/15 Michelin Energies, they seemed more sensitive to pressure change. I say this because I noticed a 2MPG gain when I upped the pressure from 30 to 44PSI. This leads me to believe that every tire compound and design will yield different results.

After 65K miles on my Pilot Sports (great tire btw), I'm going to try out the Pilot Sport PS2s. Best review from Consumer Reports and seem to have good reviews from users on tirerack.com. I'll note any fuel economy vs PSI differences.
kwong7 is offline   Reply With Quote
Old October 22nd, 2007, 14:25   #3
Mike_Van
Veteran Member
 
Mike_Van's Avatar
 
Join Date: May 2003
Location: Boulder, Colorado
Fuel Economy: ~38.8
Default

Quote:
Originally Posted by xDieselxTunerx
Whats the best psi to run my tires for the best fuel milesage? I have 205/55R16's right now im running them at 38psi. Is that perfect or too low?
For max. MPG, many folks here run 85% of the max. PSI indicated on the tire sidewall, so this value is specific to your tires. This value is usually higher than the suggested values indicated by VW (in my case, in the fuel door).
Mike_Van is offline   Reply With Quote
Old October 23rd, 2007, 08:00   #4
MBoni
Veteran Member
 
Join Date: May 2007
Location: Atlanta, GA
Cool

Just a caution:

Tire pressure usually creates a tradeoff between traction and friction. High pressure provides less friction (therefore better MPG), but also less traction. If you are planning on doing any driving where you may approach the limits of your tire's ability to stick to the road, like in twisty mountain roads, you might want to be closer to the VW recommended value.
MBoni is offline   Reply With Quote
Old October 23rd, 2007, 08:05   #5
tditom
Veteran Member
 
Join Date: Sep 2001
Location: san antonio
Fuel Economy: Golf: 54/48/43.5 B4 Passat: 52/48.5/45 B5.5 Passat: 30 mpg mixed
Default

Quote:
Originally Posted by xDieselxTunerx
Whats the best psi to run my tires for the best fuel milesage? I have 205/55R16's right now im running them at 38psi. Is that perfect or too low?
The best economy will be acheived with least rolling resistance, which would be acheived by the highest pressure the tire could handle. This wouldn't be the safest for all road conditions, though.

You might consider going to a narrower tire if you really want to have an impact on fuel economy.
__________________
-tom
current autos: 98 MB E300D-T, 09 Camry Hybrid
Find your VW part numbers here.
Why I can't recommend a tdi > MY 06 st this time
Why I recommend fuel additive.
tditom is online now   Reply With Quote
Old October 26th, 2007, 12:11   #6
kwong7
Veteran Member
 
Join Date: Mar 2004
Location: Southern Caifornia
Fuel Economy: 48/42/45 MPG
Default

I guess my previous convoluted point was that the relationship between tire pressure and fuel economy is not perfect one-to-one linear relationship. There's a point when more PSI in the tires will show a substantial benefit. I've noticed this with my Michelin Pilot Sport tires above.
kwong7 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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

Forum Jump


All times are GMT -7. The time now is 21:00.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2014
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
© 1996 - 2013, All Rights Reserved
Page generated in 0.12439 seconds with 9 queries
[Output: 70.28 Kb. compressed to 61.22 Kb. by saving 9.06 Kb. (12.89%)]