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 May 30th, 2015, 22:56   #76
Diesl
Veteran Member
 
Join Date: Dec 2012
Location: Chicago
Default

Just added the last two months to the plots in the previous post. At some point I might create a separate histogram just for the summer peak, to see whether anything pops up.
__________________
If it works, take it apart and find out why!
Diesl is offline   Reply With Quote
Old August 2nd, 2015, 21:25   #77
Diesl
Veteran Member
 
Join Date: Dec 2012
Location: Chicago
Default Roof rail filler effect

I'm done with the gaspods. Now I am tracking the influence of filling in the roof rails (with styrofoam inserts).




Early conclusion: filling in the rails does not seem to significantly improve diesel milage.
__________________
If it works, take it apart and find out why!

Last edited by Diesl; October 1st, 2015 at 14:15.
Diesl is offline   Reply With Quote
Old October 1st, 2015, 14:33   #78
Diesl
Veteran Member
 
Join Date: Dec 2012
Location: Chicago
Default pods + rail fillers

I started to check the effect of pods + rail filler, versus rail filler alone.

The hypothesis gets pretty convoluted though: to have any hope for a positive effect one would have to assume that
  1. the rails on the JSW create too much turbulence,
  2. that with filled rails there is too little turbulence/mixing of the boundary layer (leading to a low pressure pocket behind the car, i.e. same situation as in a normal non-wagon Golf),
  3. and that the pods with filled rails create just enough turbulence to fill in the low pressure pocket behind the car, but not enough to make the drag significantly worse.

After looking at the first three data points I decided that this is unlikely to lead anywhere, and that I'm done testing.



Does anybody want the pods for testing purposes?
__________________
If it works, take it apart and find out why!
Diesl is offline   Reply With Quote
Old June 28th, 2019, 14:44   #79
Diesl
Veteran Member
 
Join Date: Dec 2012
Location: Chicago
Default

Updated post #5. The best correlation seems to be between mpg and speed, with higher mpg for higher average speed. I assume this means it's simply an annual variation in city vs highway driving. Superimposed on these annual variations is a steady decline of diesel mileage for my car, from about 37 mpg in 2013-2014 to 34 mpg in 2019.
__________________
If it works, take it apart and find out why!

Last edited by Diesl; June 28th, 2019 at 14:46.
Diesl is offline   Reply With Quote
Old October 15th, 2019, 17:07   #80
jerrymander
Veteran Member
 
jerrymander's Avatar
 
Join Date: Feb 2012
Location: Cowford, FL
Default

Diesl, I used to collect all my data in spreadsheets when I first got my car. Then I realized that it didn't really matter too much to me personally. I did collect a few bullet points with my old manual CR140:

45 MPH @ 6th gear: 42 MPH w/o drafting @ -30 F (Dakota winter, heat ON) (car would idle at 1400 it was crazy to me)
45 MPH @ 6th gear: 57 MPG w/o drafting @ 70 F (Florida winter)
45 MPH @ 6th gear: 59 MPG w/o drafting @ 95 F (summer)

75 MPH @ 6th gear: 33 MPG w/o drafting @ -30 F
75 MPH @ 6th gear: 42 MPG w/o drafting @ 70 F
75 MPH @ 6th gear: 46 MPG w/o drafting @ 95 F
75 MPH @ 6th gear: 50 MPG w/o drafting @ 115 F (Nevada summer)

75 MPH @ 6th gear: 45 MPG w/ drafting @ 70 F
75 MPH @ 6th gear: 50 MPG w/ drafting @ 95 F

My 2015 and new(er) 2011 do similar. I hit peak fuel efficiency when the temperatures hit triple digits. In the beginning, I vigilantly hand calculated tank averages and found the multifunction display calculations to be reasonably accurate (<2% error). I stopped collecting this data meticulously around 2014. I almost never used my aircon. In Dakota I sporadically filled up with B10/B15 but never actually kept track of what was what.

Your decline is neat: I never noticed a trending MPG drop on my 2011 from 2011 to 2017 @ 112,000 miles, but I had no factory emissions equipment.
__________________
jerrymander is offline   Reply With Quote
Old October 16th, 2019, 04:57   #81
ksing44
Veteran Member
 
Join Date: Feb 2010
Location: Southeast PA
Default

Quote:
Originally Posted by Diesl View Post
Superimposed on these annual variations is a steady decline of diesel mileage for my car, from about 37 mpg in 2013-2014 to 34 mpg in 2019.
^^I also experienced a steady decline in mpg, even though the variations caused by changes in my commute, how fast I travel, and temperature have a bigger effect.


on Flickr
__________________
2010 Golf TDI - (BGM), 4-Dr, 6-M, Sunroof, Xenon, Dynaudio, Nav (RNS-510), Euro light switch, 9W7 BT, R Tinted LED Tail Lights, Monte Carlo 17" x 7.5" ET47 Wheels, 235/45/17 Tires, P3Cars Digital Interface, Sonniboy sunshades, CP3 HPFP: 11/8/2016 @139,848 miles, The Fix: 9/27/17 @153,289 miles

Flickr slideshow
ksing44 is offline   Reply With Quote
Old October 16th, 2019, 06:14   #82
bobt2382
Veteran Member - TDIClub Contributor
 
bobt2382's Avatar
 
Join Date: Aug 2009
Location: NJ
Fuel Economy: 46.5
Default

Quote:
Originally Posted by jerrymander View Post
Diesl, I used to collect all my data in spreadsheets when I first got my car. Then I realized that it didn't really matter too much to me personally. I did collect a few bullet points with my old manual CR140:
45 MPH @ 6th gear: 42 MPH w/o drafting @ -30 F (Dakota winter, heat ON) (car would idle at 1400 it was crazy to me)
45 MPH @ 6th gear: 57 MPG w/o drafting @ 70 F (Florida winter)
45 MPH @ 6th gear: 59 MPG w/o drafting @ 95 F (summer)
75 MPH @ 6th gear: 33 MPG w/o drafting @ -30 F
75 MPH @ 6th gear: 42 MPG w/o drafting @ 70 F
75 MPH @ 6th gear: 46 MPG w/o drafting @ 95 F
75 MPH @ 6th gear: 50 MPG w/o drafting @ 115 F (Nevada summer)
75 MPH @ 6th gear: 45 MPG w/ drafting @ 70 F
75 MPH @ 6th gear: 50 MPG w/ drafting @ 95 F
My 2015 and new(er) 2011 do similar. I hit peak fuel efficiency when the temperatures hit triple digits. In the beginning, I vigilantly hand calculated tank averages and found the multifunction display calculations to be reasonably accurate (<2% error). I stopped collecting this data meticulously around 2014. I almost never used my aircon. In Dakota I sporadically filled up with B10/B15 but never actually kept track of what was what.
Your decline is neat: I never noticed a trending MPG drop on my 2011 from 2011 to 2017 @ 112,000 miles, but I had no factory emissions equipment.
My experience concurs with yours, the hotter the weather the better the MPG. Also, the wind strength and direction would significantly impact MPG. Very noticeable during trips from San Diego to 29 Palms CA and to Reno NV on Rt. 395.
Thanks for posting your data.
__________________
2010 4D CWhite Golf TDI, 6 sp manual, Fluidampr, Bixenons, Rear Airbags, RNS-510, Dynaudio, DieselGeek SS & P2015 bracket, Force Fed Eng. Shifter Bushings. XB,UB, & RB UNIbraces; TyrolSport Brake Caliper Bushing, 2Micron Contain/PureFlow kits & timing belt cover, PolarFis MFD module, Euro light switch, R Red LED Tail Lights,Under Seat Drawers, Full color MFD cluster.
bobt2382 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
'13 TDI Wagon - Poor MPG - 10 mpg less than avg TDI in ATX TDI Fuel Economy 41 November 10th, 2019 04:40
Does regen cycle cause AC temperature increase? dee74 VW Passat Family (NMS and B7) TDIs (2012+) 3 July 27th, 2013 18:13
Close to 10% increase in mileage! kilo69 Atlantic Canada 2 March 25th, 2009 12:38
10% HP and Torque increase in 30mins??? Link977 TDI Power Enhancements 16 February 9th, 2008 10:30
Product discussion: 10% ~ 40% increase in MPG FuelBoost TDI Fuel Economy 199 September 8th, 2006 19:27


All times are GMT -7. The time now is 13:05.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2019, 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 - 2017, All Rights Reserved
Page generated in 0.12775 seconds with 13 queries
[Output: 90.66 Kb. compressed to 79.50 Kb. by saving 11.16 Kb. (12.31%)]