www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You

Order your TDIClub merchandise and help support TDIClub


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 August 6th, 2005, 04:59   #1
03BeigeGolfTDI
Member
 
Join Date: Sep 2003
Location: Massachusetts
Fuel Economy: 46mpg
Default No MPG Winner - but I\'m happy

as the name says 03 Golf GL (4 door) TDI
~34k miles
swapped out 15" steelies w/ GY's to 16" BBS RXIIs on brand new Conti's.
MPG went from 44 to 49...almost all highway. i'm a little confused about the MPG going UP but i can't complain. everything i read said "bigger wheel, lower mpg"...

will i see the same result changing to the .205 injectors too???
03BeigeGolfTDI is offline   Reply With Quote
Old August 6th, 2005, 05:02   #2
NMRJock
Veteran Member
 
Join Date: Aug 2003
Location: Grand Rapids, MI
Fuel Economy: 43, 40
Default Re: No MPG Winner - but I\'m happy

Were I to guess, your calculated mpg went up because your odometer is wrong as a result of the larger diameter tires.

http://www.miata.net/garage/tirecalc.html
NMRJock is offline   Reply With Quote
Old August 6th, 2005, 08:17   #3
jnecr
Veteran Member
 
jnecr's Avatar
 
Join Date: Oct 2004
Location: Raleigh, NC
Fuel Economy: 40ish?
Default Re: No MPG Winner - but I\'m happy

Quote:
Were I to guess, your calculated mpg went up because your odometer is wrong as a result of the larger diameter tires.

http://www.miata.net/garage/tirecalc.html

The tires are likely the same diameter. The new wheels may be much lighter than the steelies and they may be more properly inflated as well...
jnecr is offline   Reply With Quote
Old August 6th, 2005, 08:39   #4
GetMore
Veteran Member
 
Join Date: Apr 2003
Location: Patterson, New York
Fuel Economy: 56.1/42.7/38.1
Default Re: No MPG Winner - but I\'m happy

That probably explains it: lower rolling resistance due to proper inflation. Tire pressure makes a big difference.
Though one day I would like to see a comprehensive test on rim size and its effect on mileage. It'd be nice to see if going wider is the culprit, if it really is diameter, or if it's the tire itself.
GetMore is offline   Reply With Quote
Old August 6th, 2005, 09:00   #5
jnecr
Veteran Member
 
jnecr's Avatar
 
Join Date: Oct 2004
Location: Raleigh, NC
Fuel Economy: 40ish?
Default Re: No MPG Winner - but I\'m happy

Quote:
It'd be nice to see if going wider is the culprit, if it really is diameter, or if it's the tire itself.
All of the above, plus the weight distribution of the wheel/tire.
jnecr is offline   Reply With Quote
Old August 6th, 2005, 12:20   #6
Ernie Rogers
Veteran Member
 
Join Date: Oct 2001
Location: Pleasant Grove, Utah
Fuel Economy: 49/ 45/ 40
Default Re: No MPG Winner - but I\'m happy

With bigger tires, the odometer shows less miles traveled for the amount of gas. Further, IF you are careful enough to try to drive the same speed as before, the larger tires will fake you into driving faster than before. Overall consequence is that you might suppose (without making the necessary gage corrections) that fuel economy IS GOING DOWN with bigger tires, when in reality your mileage would increase (in agreement with theory). This was covered in detail in another thread.

Ernie Rogers

Quote:
Were I to guess, your calculated mpg went up because your odometer is wrong as a result of the larger diameter tires.

http://www.miata.net/garage/tirecalc.html
Ernie Rogers 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 02:06.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
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 - 2020, All Rights Reserved
Page generated in 0.13998 seconds with 10 queries
[Output: 70.05 Kb. compressed to 61.18 Kb. by saving 8.88 Kb. (12.67%)]