Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 02-08-2023, 09:50 AM   #1 (permalink)
Master EcoModder
 
Join Date: Mar 2010
Location: london, on
Posts: 337

Buggie - '01 Vw Beetle TDI Gls
Thanks: 4
Thanked 32 Times in 22 Posts
Economy after larger tire

2007 grand Cherokee diesel, engine is notoriously high revenge for diesel and many said that much lower gear would be nice to have. So I got new tires and I went up from 29.5" to a 32" diameter tire. Before with the old worn 29.5" tires my average fuel economy was 10.5 l per 100 km Now with the brand new all terrains it is 11.2 But the odometer used to be showing 5% too fast now it shows 6 km to low so I don't know how to calculate that extra percentage into the calculations. I basically go almost 10% more than I did before so the slight increase still shows like it should be A benefit Big because I cover more distance. After the first 80 miles average is down to 10.9, but i also changed axle and transfercase fluid. Gps verified distance traveled, 170 but only logged 159 on odometer


Last edited by bandit86; 02-08-2023 at 10:44 AM..
  Reply With Quote
The Following User Says Thank You to bandit86 For This Useful Post:
freebeard (02-08-2023)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 02-08-2023, 02:22 PM   #2 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,460
Thanks: 7,705
Thanked 8,526 Times in 7,016 Posts
Thanks
Quote:
Thanks: 3
Thanked 19 Times in 15 Posts
Rookie numbers.
__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________

History is a warning for the future -- Dr. John Campbell
  Reply With Quote
The Following User Says Thank You to freebeard For This Useful Post:
bandit86 (02-09-2023)
Old 02-08-2023, 03:14 PM   #3 (permalink)
Corporate imperialist
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 11,168

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 141.63 mpg (US)
Thanks: 269
Thanked 3,515 Times in 2,790 Posts
I went with the next size larger tires on my wife's car and they are usually $20 to $25 cheaper per tire then what's it's supposed to have.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
  Reply With Quote
Old 02-08-2023, 03:43 PM   #4 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,460
Thanks: 7,705
Thanked 8,526 Times in 7,016 Posts
On my VW panel van I ran staggered [bias-ply] tires: 6.00x14 front and 8.20x15 rear.

It was mostly for downforce from the slanted roof. Topped out at 85MPH, I used to race Vovlos through the Coast Range.
__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________

History is a warning for the future -- Dr. John Campbell
  Reply With Quote
Old 02-08-2023, 06:08 PM   #5 (permalink)
Master EcoModder
 
Join Date: Mar 2010
Location: london, on
Posts: 337

Buggie - '01 Vw Beetle TDI Gls
Thanks: 4
Thanked 32 Times in 22 Posts
Quote:
Originally Posted by freebeard View Post
Thanks

Rookie numbers.
None of the other forums I visit have that option I always forget about it
  Reply With Quote
The Following User Says Thank You to bandit86 For This Useful Post:
freebeard (02-08-2023)
Old 02-09-2023, 03:55 AM   #6 (permalink)
It's all about Diesel
 
cRiPpLe_rOoStEr's Avatar
 
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 12,548
Thanks: 0
Thanked 1,622 Times in 1,447 Posts
Quote:
Originally Posted by oil pan 4 View Post
I went with the next size larger tires on my wife's car and they are usually $20 to $25 cheaper per tire then what's it's supposed to have.
Nowadays some sizes in my country simply can't be found so easily from the most traditional tire brands, and 14" tires are sometimes cheaper than the 13" ones which used to be mainstream until around 10 to 15 years ago.
  Reply With Quote
Old 02-17-2023, 07:37 PM   #7 (permalink)
EcoModding Lurker
 
Join Date: Dec 2011
Location: northen Illinois
Posts: 10
Thanks: 0
Thanked 3 Times in 3 Posts
I have an offset number built into my MPG spread sheet to account for the larger size tires. It calculates true mileage based off the odometer reading as entered. Makes calculations more accurate.
Your 32" calculate to be 8.5% larger than the 29.5" but you GPS vs odo shows 7%.
Also sometimes larger tires can be significantly heavier by pounds (kilograms). That can impact fuel mileage.
  Reply With Quote
Old 02-21-2023, 04:05 AM   #8 (permalink)
It's all about Diesel
 
cRiPpLe_rOoStEr's Avatar
 
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 12,548
Thanks: 0
Thanked 1,622 Times in 1,447 Posts
Last time a friend asked me to calculate wheel well clearance of a set of tires he was willing to fit to his truck, I also had to point out to him how it could affect acceleration and how much he should de-rate the GVWR in order to keep the climbing ability. Changing tire sizes is not so plug-and-play at all...

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com